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Rule

Greenhouse Gas Emissions Standards and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles

Action

Final Rules.

Summary

EPA and NHTSA, on behalf of the Department of Transportation, are each finalizing rules to establish a comprehensive Heavy-Duty National Program that will reduce greenhouse gas emissions and fuel consumption for on-road heavy-duty vehicles, responding to the President's directive on May 21, 2010, to take coordinated steps to produce a new generation of clean vehicles. NHTSA's final fuel consumption standards and EPA's final carbon dioxide (CO 2) emissions standards are tailored to each of three regulatory categories of heavy-duty vehicles: Combination Tractors; Heavy-duty Pickup Trucks and Vans; and Vocational Vehicles. The rules include separate standards for the engines that power combination tractors and vocational vehicles. Certain rules are exclusive to the EPA program. These include EPA's final hydrofluorocarbon standards to control leakage from air conditioning systems in combination tractors, and pickup trucks and vans. These also include EPA's final nitrous oxide (N 2 O) and methane (CH 4) emissions standards that apply to all heavy-duty engines, pickup trucks and vans.

EPA's final greenhouse gas emission standards under the Clean Air Act will begin with model year 2014. NHTSA's final fuel consumption standards under the Energy Independence and Security Act of 2007 will be voluntary in model years 2014 and 2015, becoming mandatory with model year 2016 for most regulatory categories. Commercial trailers are not regulated in this phase of the Heavy-Duty National Program.

The agencies estimate that the combined standards will reduce CO 2 emissions by approximately 270 million metric tons and save 530 million barrels of oil over the life of vehicles sold during the 2014 through 2018 model years, providing over $7 billion in net societal benefits, and $49 billion in net societal benefits when private fuel savings are considered.

EPA is also finalizing provisions allowing light-duty vehicle manufacturers to use CO 2 credits to meet the light-duty vehicle N 2 O and CH 4 standards, technical amendments to the fuel economy provisions for light-duty vehicles, and a technical amendment to the criteria pollutant emissions requirements for certain switch locomotives.

Unified Agenda

Control of Greenhouse Gas Emissions From Medium and Heavy-Duty Vehicles

4 actions from November 1st, 2010 to August 2011

  • November 1st, 2010
  • November 30th, 2010
  • January 31st, 2011
    • NPRM Comment Period End
  • August 2011
    • Final Action

Commercial Medium- and Heavy-Duty On-Highway Vehicles and Work Truck Fuel Efficiency Standards

3 actions from November 30th, 2010 to August 2011

  • November 30th, 2010
  • January 31st, 2011
    • NPRM Comment Period End
  • August 2011
    • Final Rule
 

Table of Contents Back to Top

Tables Back to Top

DATES: Back to Top

These final rules are effective on November 14, 2011. The incorporation by reference of certain publications listed in this regulation is approved by the Director of the Federal Register as of November 14, 2011.

ADDRESSES: Back to Top

EPA and NHTSA have established dockets for this action under Docket ID No. EPA-HQ-OAR-2010-0162 and NHTSA-2010-0079, respectively. All documents in the docket are listed on the http://www.regulations.gov Web site. Although listed in the index, some information is not publicly available, e.g., confidential business information or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed on the Internet and will be publicly available only in hard copy form. Publicly available docket materials are available either electronically through http://www.regulations.gov or in hard copy at the following locations: EPA: EPA Docket Center, EPA/DC, EPA West Building, 1301 Constitution Ave., NW., Room 3334, Washington, DC. The Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The telephone number for the Public Reading Room is (202) 566-1744, and the telephone number for the Air Docket is (202) 566-1742. NHTSA: Docket Management Facility, M-30, U.S. Department of Transportation, West Building, Ground Floor, Rm. W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590. The Docket Management Facility is open between 9 a.m. and 5 p.m. Eastern Time, Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Back to Top

NHTSA: Lily Smith, Office of Chief Counsel, National Highway Traffic Safety Administration, 1200 New Jersey Avenue, SE., Washington, DC 20590. Telephone: (202) 366-2992. EPA: Lauren Steele, Office of Transportation and Air Quality, Assessment and Standards Division (ASD), Environmental Protection Agency, 2000 Traverwood Drive, Ann Arbor, MI 48105; telephone number: (734) 214-4788; fax number: (734) 214-4816; e-mail address: steele.lauren@epa.gov, or contact the Office of Transportation and Air Quality at OTAQPUBLICWEB@epa.gov.

SUPPLEMENTARY INFORMATION: Back to Top

A. Does this action apply to me? Back to Top

This action affects companies that manufacture, sell, or import into the United States new heavy-duty engines and new Class 2b through 8 trucks, including combination tractors, school and transit buses, vocational vehicles such as utility service trucks, as well as3/4-ton and 1-ton pickup trucks and vans. The heavy-duty category incorporates all motor vehicles with a gross vehicle weight rating of 8,500 pounds or greater, and the engines that power them, except for medium-duty passenger vehicles already covered by the greenhouse gas emissions standards and corporate average fuel economy standards issued for light-duty model year 2012-2016 vehicles. Regulated categories and entities include the following:

Category NAICS Codea Examples of potentially affected entities
Note:
aNorth American Industry Classification System (NAICS).
Industry 336111 336112 Motor Vehicle Manufacturers, Engine and Truck Manufacturers.
336120  
Industry 541514 811112 Commercial Importers of Vehicles and Vehicle Components.
811198  
Industry 336111 Alternative Fuel Vehicle Converters.
336112  
422720  
454312  
541514  
541690  
811198  
Industry 333618 336510 Manufacturers, remanufacturers and importers of locomotives and locomotive engines.

This table is not intended to be exhaustive, but rather provides a guide for readers regarding entities likely covered by these rules. This table lists the types of entities that the agencies are aware may be regulated by this action. Other types of entities not listed in the table could also be regulated. To determine whether your activities are regulated by this action, you should carefully examine the applicability criteria in the referenced regulations. You may direct questions regarding the applicability of this action to the persons listed in the preceding FOR FURTHER INFORMATION CONTACT section.

Table of Contents Back to Top

A. Does this action apply to me?

I. Overview

A. Introduction

B. Building Blocks of the Heavy-Duty National Program

C. Summary of the Final EPA and NHTSA HD National Program

D. Summary of Costs and Benefits of the HD National Program

E. Program Flexibilities

F. EPA and NHTSA Statutory Authorities

G. Future HD GHG and Fuel Consumption Rulemakings

II. Final GHG and Fuel Consumption Standards for Heavy-Duty Engines and Vehicles

A. What vehicles will be affected?

B. Class 7 and 8 Combination Tractors

C. Heavy-Duty Pickup Trucks and Vans

D. Class 2b-8 Vocational Vehicles

E. Other Standards

III. Feasibility Assessments and Conclusions

A. Class 7-8 Combination Tractor

B. Heavy-Duty Pickup Trucks and Vans

C. Class 2b-8 Vocational Vehicles

IV. Final Regulatory Flexibility Provisions

A. Averaging, Banking, and Trading Program

B. Additional Flexibility Provisions

V. NHTSA and EPA Compliance, Certification, and Enforcement Provisions

A. Overview

B. Heavy-Duty Pickup Trucks and Vans

C. Heavy-Duty Engines

D. Class 7 and 8 Combination Tractors

E. Class 2b-8 Vocational Vehicles

F. General Regulatory Provisions

G. Penalties

VI. How will this program impact fuel consumption, GHG emissions, and climate change?

A. What methodologies did the agencies use to project GHG emissions and fuel consumption impacts?

B. MOVES Analysis

C. What are the projected reductions in fuel consumption and GHG emissions?

D. Overview of Climate Change Impacts From GHG Emissions

E. Changes in Atmospheric CO 2 Concentrations, Global Mean Temperature, Sea Level Rise, and Ocean pH Associated With the Program's GHG Emissions Reductions

VII. How will this final action impact non-ghg emissions and their associated effects?

A. Emissions Inventory Impacts

B. Health Effects of Non-GHG Pollutants

C. Environmental Effects of Non-GHG Pollutants

D. Air Quality Impacts of Non-GHG Pollutants

VIII. What are the agencies' estimated cost, economic, and other impacts of the final program?

A. Conceptual Framework for Evaluating Impacts

B. Costs Associated With the Final Program

C. Indirect Cost Multipliers

D. Cost per Ton of Emissions Reductions

E. Impacts of Reduction in Fuel Consumption

F. Class Shifting and Fleet Turnover Impacts

G. Benefits of Reducing CO 2 Emissions

H. Non-GHG Health and Environmental Impacts

I. Energy Security Impacts

J. Other Impacts

K. The Effect of Safety Standards and Voluntary Safety Improvements on Vehicle Weight

L. Summary of Costs and Benefits

M. Employment Impacts

IX. Analysis of the Alternatives

A. What are the alternatives that the agencies considered?

B. How do these alternatives compare in overall GHG emissions reductions and fuel efficiency and cost?

C. What is the agencies' decision regarding trailer standards?

X. Public Participation

XI. NHTSA's Record of Decision

A. The Agency's Decision

B. Alternatives Considered by NHTSA in Reaching Its Decision, Including the Environmentally Preferable Alternative

C. Factors Balanced by NHTSA in Making Its Decision

D. How the Factors and Considerations Balanced by NHTSA Entered Into Its Decision

E. The Agency's Preferences Among Alternatives Based on Relevant Factors, Including Economic and Technical Considerations and Agency Statutory Missions

F. Mitigation

XII. Statutory and Executive Order Reviews

XIII. Statutory Provisions and Legal Authority

A. EPA

B. NHTSA

I. Overview Back to Top

A. Introduction

EPA and NHTSA (“the agencies”) are announcing a first-ever program to reduce greenhouse gas (GHG) emissions and fuel consumption in the heavy-duty highway vehicle sector. This broad sector—ranging from large pickups to sleeper-cab tractors—together represent the second largest contributor to oil consumption and GHG emissions from the mobile source sector, after light-duty passenger cars and trucks. These are the second joint rules issued by the agencies, following on the April 1, 2010 standards to sharply reduce GHG emissions and fuel consumption from MY 2012-2016 passenger cars and light trucks (published on May 7, 2010 at 75 FR 25324).

In a May 21, 2010 memorandum to the Administrators of EPA and NHTSA (and the Secretaries of Transportation and Energy), the President stated that “America has the opportunity to lead the world in the development of a new generation of clean cars and trucks through innovative technologies and manufacturing that will spur economic growth and create high-quality domestic jobs, enhance our energy security, and improve our environment.”1 2 In the May 2010 memorandum, the President specifically requested the Administrators of EPA and NHTSA to “immediately begin work on a joint rulemaking under the Clean Air Act (CAA) and the Energy Independence and Security Act of 2007 (EISA) to establish fuel efficiency and greenhouse gas emissions standards for commercial medium-and heavy-duty on-highway vehicles and work trucks beginning with the 2014 model year (MY).” In this final rulemaking, each agency is addressing this Memorandum by adopting rules under its respective authority that together comprise a coordinated and comprehensive HD National Program designed to address the urgent and closely intertwined challenges of reduction of dependence on oil, achievement of energy security, and amelioration of global climate change.

At the same time, the final program will enhance American competitiveness and job creation, benefit consumers and businesses by reducing costs for transporting goods, and spur growth in the clean energy sector.

The HD National Program the agencies are finalizing today reflects a collaborative effort between the agencies, a range of public interest nongovernmental organizations (NGOs), the state of California and the regulated industry. At the time of the President's announcement, a number of major HD truck and engine manufacturers representing the vast majority of this industry, and the California Air Resources Board (California ARB), sent letters to EPA and NHTSA supporting the creation of a HD National Program based on a common set of principles. In the letters, the stakeholders committed to working with the agencies and with other stakeholders toward a program consistent with common principles, including:

Increased use of existing technologies to achieve significant GHG emissions and fuel consumption reductions;

A program that starts in 2014 and is fully phased in by 2018;

A program that works towards harmonization of methods for determining a vehicle's GHG and fuel efficiency, recognizing the global nature of the issues and the industry;

Standards that recognize the commercial needs of the trucking industry; and

Incentives leading to the early introduction of advanced technologies.

The final rules adopted today reflect these principles. The final HD National Program also builds on many years of heavy-duty engine and vehicle technology development to achieve what the agencies believe is the greatest degree of fuel consumption and GHG emission reduction appropriate, technologically and economically feasible, and cost-effective for model years 2014-2018. In addition to taking aggressive steps that are reasonably possible now, based on the technological opportunities and pathways that present themselves during these model years, the agencies and industry will also continue learning about emerging opportunities for this complex sector to further reduce fuel consumption and GHG emission through future regulatory steps.

Similarly, the agencies will participate in efforts to improve our ability to accurately characterize the actual in-use fuel consumption and emissions of this complex sector. As technologies progress in the coming years and as the agencies improve the regulatory tools to evaluate real world vehicle performance, we expect that we will develop a second phase of regulations to reinforce these initial rules and achieve further reductions in GHG emissions and fuel consumption reduction for the mid- and longer-term time frame (beyond 2018). The agencies are committed to working with all interested stakeholders in this effort and to the extent possible working towards alignment with similar programs being developed in Canada, Mexico, Europe, China, and Japan. In doing so, we will continue to evaluate many of the structural and technical decisions we are making in today's final action in the context of new technologies and the new regulatory tools that we expect to realize in the future.

The regulatory program we are finalizing today is largely unchanged from the proposal the agencies made on November 30, 2010 (See 75 FR 741512). The structure of the program and the stringency of the standards are essentially the same as proposed. We have made a number of changes to the testing requirements and reporting requirements to provide greater regulatory certainty and better align the NHTSA and EPA portions of the program. In response to comments, we have also made some changes to the averaging, banking and trading (ABT) provisions of the program that will make implementation of this final program more flexible for manufacturers. We have added provisions to further encourage the development of advanced technologies and to provide a more straightforward mechanism to certify engines and vehicles using innovative technologies. Finally in response to comments, we have made some technical changes to our emissions compliance model that results in different numeric standards for both combination tractors and vocational vehicles to more accurately characterize emissions while maintaining the same overall stringency and therefore expected costs and benefits of the program.

Heavy-duty vehicles move much of the nation's freight and carry out numerous other tasks, including utility work, concrete delivery, fire response, refuse collection, and many more. Heavy-duty vehicles are primarily powered by diesel engines, although about 37 percent of these vehicles are powered by gasoline engines. [3] Heavy-duty trucks [4] have long been an important part of the goods movement infrastructure in this country and have experienced significant growth over the last decade related to increased imports and exports of finished goods and increased shipping of finished goods to homes through Internet purchases.

The heavy-duty sector is extremely diverse in several respects, including types of manufacturing companies involved, the range of sizes of trucks and engines they produce, the types of work the trucks are designed to perform, and the regulatory history of different subcategories of vehicles and engines. The current heavy-duty fleet encompasses vehicles from the “18-wheeler” combination tractors one sees on the highway to school and transit buses, to vocational vehicles such as utility service trucks, as well as the largest pickup trucks and vans.

For purposes of this preamble, the term “heavy-duty” or “HD” is used to apply to all highway vehicles and engines that are not within the range of light-duty vehicles, light-duty trucks, and medium-duty passenger vehicles (MDPV) covered by the GHG and Corporate Average Fuel Economy (CAFE) standards issued for MY 2012-2016. [5] It also does not include motorcycles. Thus, in this rulemaking, unless specified otherwise, the heavy-duty category incorporates all vehicles with a gross vehicle weight rating above 8,500 pounds, and the engines that power them, except for MDPVs. [6]

The agencies proposed to cover all segments of the heavy-duty category above, except with respect to recreational vehicles (RVs or motor homes). We note that the Energy Independence and Security Act of 2007 requires NHTSA to set standards for “commercial medium- and heavy-duty on-highway vehicles and work trucks.” [7] The standards that EPA is finalizing today cover recreational on-highway vehicles, while NHTSA proposed not to include recreational vehicles based on an interpretation of the term “commercial medium- and heavy-duty on-highway commercial” vehicles. NHTSA stated in the NPRM that recreational vehicles are non-commercial, and therefore outside of the term and the scope of its rule.

Oshkosh Corporation commented that this interpretation did not match the statutory definition of the term in EISA, which defines “commercial medium- and heavy-duty on-highway vehicle” by weight only, [8] and that therefore the agency's interpretation of the term should be explicitly broadened to include all vehicles, and more than only vehicles that are not engaged in interstate commerce as defined by the Federal Motor Carrier Safety Administration in 49 CFR part 202. Alternatively, Oshkosh suggested that if NHTSA followed the definition provided in EISA, which makes no direct reference to the concept of “commercial,” there would be no logical reason to exclude RVs based on that definition.

NHTSA has considered Oshkosh's comment and reconsidered its interpretation that effectively read words into the statutory definition. Given the very wide variety of vehicles contained in the HD fleet, reading those words into the definition and thereby excluding certain types of vehicles could create illogical results, i.e., treating similar vehicles differently. Therefore, NHTSA will adhere to the statutory definition contained in EISA for this rulemaking. However, as RVs were not included by NHTSA in the proposed regulation in the NPRM, they are not within the scope and must be excluded in NHTSA's portion of the final program. Accordingly, NHTSA will address this issue in the next rulemaking. However, as noted, RVs are subject to the CO 2 standards for vocational vehicles.

Setting fuel consumption standards for the heavy-duty sector, pursuant to NHTSA's EISA authority, will also improve our energy and national security by reducing our dependence on foreign oil, which has been a national objective since the first oil price shocks in the 1970s. Net petroleum imports now account for approximately 49-51 percent of U.S. petroleum consumption. World crude oil production is highly concentrated, exacerbating the risks of supply disruptions and price shocks as the recent unrest in North Africa and the Persian Gulf highlights. Recently, oil prices have been over $100 per barrel, gasoline and diesel fuel prices in excess of $4 per gallon, causing financial hardship for many families and businesses. The export of U.S. assets in exchange for oil imports continues to be an important component of the historically unprecedented U.S. trade deficits. Transportation accounts for about 72 percent of U.S. petroleum consumption. Heavy-duty vehicles account for about 17 percent of transportation oil use, which means that they alone account for about 12 percent of all U.S. oil consumption. [9]

Setting GHG emissions standards for the heavy-duty sector will help to ameliorate climate change. The EPA Administrator found after a thorough examination of the scientific evidence on the causes and impact of current and future climate change, and careful review of public comments, that the science compellingly supports a positive finding that atmospheric concentrations of six greenhouse gases taken in combination result in air pollution which may reasonably be anticipated to endanger both public health and welfare and that the combined emissions of these greenhouse gases from new motor vehicles and engines contributes to the greenhouse gas air pollution that endangers public health and welfare. In her finding, the Administrator carefully studied and relied heavily upon the major findings and conclusions from the recent assessments of the U.S. Climate Change Science Program and the U.N. Intergovernmental Panel on Climate Change. 74 FR 66496, December 15, 2009. As summarized in the Technical Support Document for EPA's Endangerment and Cause or Contribute Findings under section 202(a) of the Clean Air Act, anthropogenic emissions of GHGs are very likely (a 90 to 99 percent probability) the cause of most of the observed global warming over the last 50 years. [10] Primary GHGs of concern are carbon dioxide (CO 2), methane (CH 4), nitrous oxide (N 2 O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF 6). Mobile sources emitted 31 percent of all U.S. GHGs in 2007 (transportation sources, which do not include certain off-highway sources, account for 28 percent) and have been the fastest-growing source of U.S. GHGs since 1990. [11] Mobile sources addressed in EPA's endangerment and contribution findings under CAA section 202(a)—light-duty vehicles, heavy-duty trucks, buses, and motorcycles—accounted for 23 percent of all U.S. GHG emissions in 2007. [12] Heavy-duty vehicles emit CO 2, CH 4, N 2 O, and HFCs and are responsible for nearly 19 percent of all mobile source GHGs (nearly 6 percent of all U.S. GHGs) and about 25 percent of section 202(a) mobile source GHGs. For heavy-duty vehicles in 2007, CO 2 emissions represented more than 99 percent of all GHG emissions (including HFCs). [13]

In developing this HD National program, the agencies have worked with a large and diverse group of stakeholders representing truck and engine manufacturers, trucking fleets, environmental organizations, and states including the State of California. [14] Further, it is our expectation based on our ongoing work with the State of California that the California ARB will be able to adopt regulations equivalent in practice to those of this HD National Program, just as it has done for past EPA regulation of heavy-duty trucks and engines. NHTSA and EPA have been working with California ARB to enable that outcome.

In light of the industry's diversity, and consistent with the recommendations of the National Academy of Sciences (NAS) as discussed further below, the agencies are adopting a HD National Program that recognizes the different sizes and work requirements of this wide range of heavy-duty vehicles and their engines. NHTSA's final fuel consumption standards and EPA's final GHG standards apply to manufacturers of the following types of heavy-duty vehicles and their engines; the final provisions for each of these are described in more detail below in this section:

  • Heavy-duty Pickup Trucks and Vans.
  • Combination Tractors.
  • Vocational Vehicles.

As in the light-duty 2012-2016 MY vehicle rule, EPA's and NHTSA's final standards for the heavy-duty sector are largely harmonized with one another due to the close and direct relationship between improving the fuel efficiency of these vehicles and reducing their CO 2 tailpipe emissions. For all vehicles that consume carbon-based fuels, the amount of CO 2 exhaust emissions is essentially constant per gallon for a given type of fuel that is consumed. The more efficient a heavy-duty truck is in completing its work, the lower its environmental impact will be, because the less fuel consumed to move cargo a given distance, the less CO 2 that truck emits directly into the air. The technologies available for improving fuel efficiency, and therefore for reducing both CO 2 emissions and fuel consumption, are one and the same. [15] Because of this close technical relationship, NHTSA and EPA have been able to rely on jointly-developed assumptions, analyses, and analytical conclusions to support the standards and other provisions that NHTSA and EPA are adopting under our separate legal authorities.

This program is based on standards for direct exhaust emissions from engines and vehicles. In characterizing the overall emissions impacts, benefits and costs of the program, analyses of air pollutant emissions from upstream sources have been conducted. In this action, the agencies use the term upstream to include emissions from the production and distribution of fuel. A summary of the analysis of upstream emissions can be found in Section VI.C of this preamble, and further details are available in Chapter 5 of the RIA.

The timelines for the implementation of the final NHTSA and EPA standards are also closely coordinated. EPA's final GHG emission standards will begin in model year 2014. In order to provide for the four full model years of regulatory lead time required by EISA, as discussed in Section 0 below, NHTSA's final fuel consumption standards will be voluntary in model years 2014 and 2015, becoming mandatory in model year 2016, except for diesel engine standards which will be voluntary in model years 2014, 2015 and 2016, becoming mandatory in model year 2017. Both agencies are also allowing for early compliance in model year 2013. A detailed discussion of how the final standards are consistent with each agency's respective statutory requirements and authorities is found later in this preamble.

Allison Transmission stated that sufficient time must be taken before issuing the final rules in order to ensure that the standards are supportable. As explained in Sections II and III below, as well as in the RIA, the agencies believe there is sufficient lead time to meet all of the standards adopted in today's rules. For those areas for which the agencies have determined that insufficient time is available to develop appropriate standards, such as for trailers, the agencies are not including regulations as part of this initial program.

NHTSA received several comments related to the timing of the implementation of its fuel consumption standards. The Engine Manufacturers Association (EMA), the National Automobile Dealers Association (NADA), The Volvo Group (Volvo), and Navistar argued that the timing of NHTSA's standards violated the lead time requirement of 49 U.S.C. 32902(k)(3)(A), which states that standards under the new medium- and heavy-duty program shall have “not less than 4 full model years of regulatory lead-time.” The commenters seemed to interpret the voluntary program as the imposition of regulation upon industry. NADA described NHTSA's standards during the voluntary period as “mandates.”

NHTSA has reviewed this issue and believes that the regulatory schedule is consistent with the lead time requirement of Section 32902(k)(3). To clarify, NHTSA will not be imposing a mandatory regulatory program until 2016, and none of the voluntary standards will be “mandates.” As described in later sections, the voluntary standards would only apply to a manufacturer if it makes the voluntary and affirmative choice to opt-in to the program. [16] Mandatory NHTSA standards will first come into effect in 2016, giving industry four full years of lead time with the NHTSA fuel consumption standards.

EMA, NADA, and Navistar also argued that the proposed standards would violate the stability requirement of 49 U.S.C. 32902(k)(3)(B), which states that they shall have “not less than 3 full model years of regulatory stability.” EMA stated that since there are HD emission standards taking effect in 2013, the 2014 implementation date for this rule would violate the stability requirements. NADA argued that the MY 2014-2017/2018 phase-in period was inadequate to fulfill the stability requirement.

Congress has not spoken directly to the meaning of the words “regulatory stability.” NHTSA believes that the “regulatory stability” requirement exists to ensure that manufacturers will not be subject to new standards in repeated rulemakings too rapidly, given that Congress did not include a minimum duration period for the MD/HD standards. [17] NHTSA further believes that standards, which as set provide for increasing stringency during the period that the standards are applicable under this rule to be the maximum feasible during the regulatory period, are within the meaning of the statute. In this statutory context, NHTSA interprets the phrase “regulatory stability” in Section 32902(k)(3)(B) as requiring that the standards remain in effect for three years before they may be increased by amendment. It does not prohibit standards which contain pre-determined stringency increases.

As laid out in Section II below, NHTSA's final standards follow different phase-in schedules based on differences between the regulatory categories. Consistent with NHTSA's statutory obligation to implement a program designed to achieve the maximum feasible fuel efficiency improvement, the standards increase in stringency based upon increasing fleet penetration rates for the available technologies. The NPRM proposed phase-in schedules aligned with EPA's, some of which followed pre-determined stringency increases. The NPRM also noted that NHTSA was considering alternate standards that would not change in stringency during the time frame when the regulations are effective for those standards that increased throughout the mandatory program. As described in Section II below, the final rule includes the proposed alternate standards for those standards that follow such a stringency phase-in path. Therefore, NHTSA believes that the final rule provides ample stability for each standard.

Each standard, associated phase-in schedule, and alternative standard implemented by this final rule was noticed in the NPRM. Those fuel consumption standards that become mandatory in 2017 will remain in effect through at least 2019. This further ensures that the fuel consumption standards in this rule will remain in effect for at least three years, providing the statutorily-mandated three full years of regulatory stability, and ensuring that manufacturers will not be subject to new or amended standards too rapidly. (The greenhouse gas emission standards remain in effect unless and until amended in all later model years in any case.) Therefore, NHTSA believes the commenters' concern about regulatory stability is addressed in the structure of the rule.

Neither EPA nor NHTSA is adopting standards at this time for GHG emissions or fuel consumption, respectively, for heavy-duty commercial trailers or for vehicles or engines manufactured by small businesses. The agencies recognize that aerodynamic and tire rolling resistance improvements to trailers represent a significant opportunity to reduce fuel consumption and GHGs as evidenced, among other things, by the work of the EPA SmartWay program. While we are deferring action today on setting trailer standards, the agencies are committed to moving forward to create a regulatory program for trailers that would complement the current vehicle program. See Section IX for more details on the agencies' decisions regarding trailers, and Sections II and XII for more details on the agencies' decisions regarding small businesses.

The agencies have analyzed in detail the projected costs, fuel savings, and benefits of the final GHG and fuel consumption standards. Table I-1 shows estimated lifetime discounted program costs (including technological outlays), fuel savings, and benefits for all heavy-duty vehicles projected to be sold in model years 2014-2018 over these vehicles' lives. Section I.D includes additional information about this analysis.

Table I-1—Estimated Lifetime Discounted Costs, Fuel Savings, Benefits, and Net Benefits for 2014-2018 Model Year Heavy-Duty Vehicles a b Back to Top
[Billions, 2009$]
Notes:
a The agencies estimated the benefits associated with four different values of a one ton CO 2 reduction (model average at 2.5% discount rate, 3%, and 5%; 95th percentile at 3%), which each increase over time. For the purposes of this overview presentation of estimated costs and benefits, however, we are showing the benefits associated with the marginal value deemed to be central by the interagency working group on this topic: the model average at 3% discount rate, in 2009 dollars. Section VIII.F provides a complete list of values for the 4 estimates.
b Note that net present value of reduced GHG emissions is calculated differently than other benefits. The same discount rate used to discount the value of damages from future emissions (SCC at 5, 3, and 2.5 percent) is used to calculate net present value of SCC for internal consistency. Refer to Section VIII.F for more detail.
c Present value is the total, aggregated amount that a series of monetized costs or benefits that occur over time is worth now (in year 2009 dollar terms), discounting future values to the present.
d Net benefits reflect the fuel savings plus benefits minus costs.
e The annualized value is the constant annual value through a given time period (2012 through 2050 in this analysis) whose summed present value equals the present value from which it was derived.
Lifetime Present Valuec—3% Discount Rate  
Program Costs $8.1
Fuel Savings 50
Benefits 7.3
Net Benefitsd 49
Annualized Valuee—3% Discount Rate  
Annualized Costs 0.4
Fuel Savings 2.2
Annualized Benefits 0.4
Net Benefitsd 2.2
Lifetime Present Valuec—7% Discount Rate  
Program Costs 8.1
Fuel Savings 34
Benefits 6.7
Net Benefitsd 33
Annualized Valuee—7% Discount Rate  
Annualized Costs 0.6
Fuel Savings 2.6
Annualized Benefits 0.5
Net Benefitsd 2.5

B. Building Blocks of the Heavy-Duty National Program

The standards that are being adopted in this notice represent the first time that NHTSA and EPA are regulating the heavy-duty sector for fuel consumption and GHG emissions, respectively. The HD National Program is rooted in EPA's prior regulatory history, the SmartWay® Transport Partnership program, and extensive technical and engineering analyses done at the federal level. This section summarizes some of the most important of these precursors and foundations for this HD National Program.

(1) EPA's Traditional Heavy-Duty Regulatory Program

Since the 1980s, EPA has acted several times to address tailpipe emissions of criteria pollutants and air toxics from heavy-duty vehicles and engines. During the last 18 years, these programs have primarily addressed emissions of particulate matter (PM) and the primary ozone precursors, hydrocarbons (HC) and oxides of nitrogen (NO X). These programs have successfully achieved significant and cost-effective reductions in emissions and associated health and welfare benefits to the nation. They have been structured in ways that account for the varying circumstances of the engine and truck industries. As required by the CAA, the emission standards implemented by these programs include standards that apply at the time that the vehicle or engine is sold as well as standards that apply in actual use. As a result of these programs, new vehicles meeting current emission standards will emit 98 percent less NO X and 99 percent less PM than new trucks 20 years ago. The resulting emission reductions provide significant public health and welfare benefits. The most recent EPA regulations which were fully phased-in in 2010, the monetized health and welfare benefits alone are projected to be greater than $70 billion in 2030—benefits far exceeding compliance costs and not including the unmonetized benefits resulting from reductions in air toxics and ozone precursors (66 FR 5002, January 18, 2001).

EPA's overall program goal has always been to achieve emissions reductions from the complete vehicles that operate on our roads. The agency has often accomplished this goal for many heavy-duty truck categories through the regulation of heavy-duty engine emissions. A key part of this success has been the development over many years of a well-established, representative, and robust set of engine test procedures that industry and EPA now routinely use to measure emissions and determine compliance with emission standards. These test procedures in turn serve the overall compliance program that EPA implements to help ensure that emissions reductions are being achieved. By isolating the engine from the many variables involved when the engine is installed and operated in a HD vehicle, EPA has been able to accurately address the contribution of the engine alone to overall emissions. The agencies discuss below how the final program incorporates the existing engine-based approach used for criteria pollutant regulations, as well as new vehicle-based approaches.

(2) NHTSA's Responsibilities To Regulate Heavy-Duty Fuel Efficiency under EISA

With the passage of the EISA in December 2007, Congress laid out a framework developing the first fuel efficiency regulations for HD vehicles. As codified at 49 U.S.C. 32902(k), EISA requires NHTSA to develop a regulatory system for the fuel efficiency of commercial medium-duty and heavy-duty on-highway vehicles and work trucks in three steps: a study by NAS, a study by NHTSA, [18] and a rulemaking to develop the regulations themselves.

Specifically, section 102 of EISA, codified at 49 U.S.C. 32902(k)(2), states that not later than two years after completion of the NHTSA study, DOT (by delegation, NHTSA), in consultation with the Department of Energy (DOE) and EPA, shall develop a regulation to implement a “commercial medium-duty and heavy-duty on-highway vehicle and work truck fuel efficiency improvement program designed to achieve the maximum feasible improvement.” NHTSA interprets the timing requirements as permitting a regulation to be developed earlier, rather than as requiring the agency to wait a specified period of time.

Congress specified that as part of the “HD fuel efficiency improvement program designed to achieve the maximum feasible improvement,” NHTSA must adopt and implement:

Appropriate test methods;

Measurement metrics;

Fuel economy standards; [19] and

Compliance and enforcement protocols.

Congress emphasized that the test methods, measurement metrics, standards, and compliance and enforcement protocols must all be appropriate, cost-effective, and technologically feasible for commercial medium-duty and heavy-duty on-highway vehicles and work trucks. NHTSA notes that these criteria are different from the “four factors” of 49 U.S.C. 32902(f) [20] that have long governed NHTSA's setting of fuel economy standards for passenger cars and light trucks, although many of the same issues are considered under each of these provisions.

Congress also stated that NHTSA may set separate standards for different classes of HD vehicles, which the agency interprets broadly to allow regulation of HD engines in addition to HD vehicles, and provided requirements new to 49 U.S.C. 32902 in terms of timing of regulations, stating that the standards adopted as a result of the agency's rulemaking shall provide not less than four full model years of regulatory lead time, and three full model years of regulatory stability.

(3) National Academy of Sciences Report on Heavy-Duty Technology

In April 2010 as mandated by Congress in EISA, the National Research Council (NRC) under NAS issued a report to NHTSA and to Congress evaluating medium-duty and heavy-duty truck fuel efficiency improvement opportunities, titled “Technologies and Approaches to Reducing the Fuel Consumption of Medium- and Heavy-duty Vehicles.” [21] This study covers the same universe of heavy-duty vehicles that is the focus of this final rulemaking—all highway vehicles that are not light-duty, MDPVs, or motorcycles. The agencies have carefully evaluated the research supporting this report and its recommendations and have incorporated them to the extent practicable in the development of this rulemaking.

The NAS report is far reaching in its review of the technologies that are available and which may become available in the future to reduce fuel consumption from medium and heavy-duty vehicles. In presenting the full range of technical opportunities the report includes technologies which may not be available until 2020 or even further into the future. As such, the report provides not only a valuable list of off the shelf technologies from which the agencies have drawn in developing this near-term 2014-2018 program consistent with statutory authorities and with the set of principles set forth by the President, but the report also provides a road map the agencies can use as we look to develop future regulations for this sector. A review of the technologies in the NAS report makes clear that there are not only many technologies readily available today to achieve important reductions in fuel consumption, like the ones we used in developing the 2014-2018 program, but there are also great opportunities for even larger reductions in the future through the development of advanced hybrid drive systems and sophisticated engine technologies such as Rankine waste heat recovery. The agencies will again make extensive use of this report when we move forward to develop the next phase of regulations for medium and heavy-duty vehicles.

Allison Transmission commented that NHTSA (implicitly, both agencies) had improperly relied on the NAS report and failed to do sufficient independent analysis, which Allison claimed did not meet the statutory obligation to provide an adequate basis for the rule. First, an agency does not improperly delegate its authority or judgment merely by using work performed by outside parties as the factual basis for its decision making. See U .S. Telecom Ass'n v. FCC, 359 F.3d 554, 568 (DC Cir. 2004); United Steelworkers of Am. v. Marshall, 647 F.2d 1189, 1216-17 (DC Cir. 1980). Here, although EPA and NHTSA carefully considered the NAS report, the agencies' consideration and use of the report was not uncritical and the agencies exercised reasonable independent judgment in developing the proposed and final rules. Consistent with EISA's direction, NAS submitted a report evaluating MD/HD fuel economy standards to NHTSA in March of 2010. Indeed, many commenters argued that the agencies should have adopted more of the NAS report recommendations. The agencies reviewed the findings and recommendations of the NAS report when developing the proposed rules, as was clearly intended by Congress, but also conducted an independent study, as described throughout the record to the proposal and summarized in Section X of the NPRM, 75 FR at 74351-56. In conducting its analysis of the NAS report, the agencies found that several key recommendations, such as the use of fuel efficiency metrics, were the best approach to implementing the new program. However, the agencies rejected other recommendations of the NAS report, for example, by proposing separate regulation of engines and vehicles and the regulation of large manufacturers.

(4) The NHTSA and EPA Light-Duty National GHG and Fuel Economy Program

On May 7, 2010, EPA and NHTSA finalized the first-ever National Program for light-duty cars and trucks, which set GHG emissions and fuel economy standards for model years 2012-2016 (See 75 FR 25324). The agencies have used the light-duty National Program as a model for this final HD National Program in many respects. This is most apparent in the case of heavy-duty pickups and vans, which are very similar to the light-duty trucks addressed in the light-duty National Program both technologically as well as in terms of how they are manufactured (i.e., the same company often makes both the vehicle and the engine). For these vehicles, there are close parallels to the light-duty program in how the agencies have developed our respective final standards and compliance structures, although, as discussed below, the technologies applied to light-duty trucks are not invariably applicable to heavy-duty pickups and vans at the same penetration rates in the lead time afforded in this heavy-duty action. Another difference is that each agency adopts standards based on attributes other than vehicle footprint, as discussed below.

Due to the diversity of the remaining HD vehicles, there are fewer parallels with the structure of the light-duty program. However, the agencies have maintained the same collaboration and coordination that characterized the development of the light-duty program. Most notably, as with the light-duty program, manufacturers will be able to design and build vehicles to meet a closely coordinated, harmonized national program, and avoid unnecessarily duplicative testing and compliance burdens.

(5) EPA's SmartWay Program

EPA's voluntary SmartWay Transport Partnership program encourages shipping and trucking companies to take actions that reduce fuel consumption and CO 2 by working with the shipping community and the freight sector to identify low carbon strategies and technologies, and by providing technical information, financial incentives, and partner recognition to accelerate the adoption of these strategies. Through the SmartWay program, EPA has worked closely with truck manufacturers and truck fleets to develop test procedures to evaluate vehicle and component performance in reducing fuel consumption and has conducted testing and has established test programs to verify technologies that can achieve these reductions. Over the last six years, EPA has developed hands-on experience testing the largest heavy-duty trucks and evaluating improvements in tire and vehicle aerodynamic performance. In 2010, according to vehicle manufacturers, approximately five percent of new combination heavy-duty trucks will meet the SmartWay performance criteria demonstrating that they represent the pinnacle of current heavy-duty truck reductions in fuel consumption.

In developing this HD National Program, the agencies have drawn from the SmartWay experience, as discussed in detail both in Sections II and III below (e.g., developing test procedures to evaluate trucks and truck components) but also in the RIA (estimating performance levels from the application of the best available technologies identified in the SmartWay program). These technologies provide part of the basis for the GHG emission and fuel consumption standards in this rulemaking for certain types of new heavy-duty Class 7 and 8 combination tractors.

In addition to identifying technologies, the SmartWay program includes operational approaches that truck fleet owners as well as individual drivers and their freight customers can incorporate, that the NHTSA and EPA believe will complement the final standards. These include such approaches as improved logistics and driver training, as discussed in the RIA. This approach is consistent with the one of the three alternative approaches that the NAS recommended be considered. The three approaches were raising fuel taxes, relaxing truck size and weight restrictions, and encouraging incentives to disseminate information to inform truck drivers about the relationship between driving behavior and fuel savings. Taxes and truck size and weight limits are mandated by public law; as such, these options are outside EPA's and NHTSA's authority to implement. However, complementary operational measures like driver training, which SmartWay does promote, can complement the final standards and also provide benefits for the existing truck fleet, furthering the public policy objectives of addressing energy security and climate change.

(6) Environment Canada

The Government of Canada's Department of the Environment (Environment Canada) assisted EPA's development of this rulemaking by conducting emissions testing of heavy-duty vehicles at their test facilities to gather data on a range of possible test cycles, and to evaluate the impact of certain emissions reduction technologies. Environment Canada also facilitated the evaluation of heavy-duty vehicle aerodynamic properties at Canada's National Research Council wind tunnel, and during coastdown testing.

We expect the technical collaboration with Environment Canada to continue as we implement testing and compliance verification procedures for this rulemaking. We may also begin to develop a knowledge base enabling improvement upon this regulatory framework for model years beyond 2018 (for example, improvements to the means of demonstrating compliance). We also expect to continue our collaboration with Environment Canada on compliance issues.

Collaboration with Environment Canada is taking place under the Canada-U.S. Air Quality Committee.

C. Summary of the Final EPA and NHTSA HD National Program

When EPA first addressed emissions from heavy-duty trucks in the 1980s, it established standards for engines, based on the amount of work performed (grams of pollutant per unit of work, expressed as grams per brake horsepower-hour or g/bhp-hr). [22] This approach recognized the fact that engine characteristics are the dominant determinant of the types of emissions generated, and engine-based technologies (including exhaust aftertreatment systems) need to be the focus for addressing those emissions. Vehicle-based technologies, in contrast, have less influence on overall truck emissions of the pollutants that EPA has regulated in the past. The engine testing approach also recognized the relatively small number of distinct heavy-duty engine designs, as compared to the extremely wide range of truck designs. EPA concluded at that time that any incremental gain in conventional emission control that could be achieved through regulation of the complete vehicle would be small in comparison to the cost of addressing the many variants of complete trucks that make up the heavy-duty sector—smaller and larger vocational vehicles for dozens of purposes, various designs of combination tractors, and many others.

Addressing GHG emissions and fuel consumption from heavy-duty trucks, however, requires a different approach. Reducing GHG emissions and fuel consumption requires increasing the inherent efficiency of the engine as well as making changes to the vehicles to reduce the amount of work demanded from the engine in order to move the truck down the road. A focus on the entire vehicle is thus required. For example, in addition to the basic emissions and fuel consumption levels of the engine, the aerodynamics of the vehicle can have a major impact on the amount of work that must be performed to transport freight at common highway speeds. For this first rulemaking, the agencies proposed a complementary engine and vehicle approach in order to achieve the maximum feasible near-term reductions.

NHTSA received comments on the proposal to create complementary engine and vehicle standards. Volvo and Daimler argued that EISA limited NHTSA's authority to the regulation of completed vehicles and did not give NHTSA authority to regulate engines. 49 U.S.C. 32902(k)(2) grants NHTSA broad authority to regulate this sector, stating simply that the Secretary “shall determine in a rulemaking proceeding how to implement a commercial medium- and heavy-duty on-highway vehicle and work truck fuel efficiency improvement program designed to achieve the maximum feasible improvement,” considering appropriateness, cost-effectiveness, and technological feasibility. NHTSA does not believe that this language precludes the regulation of engines, but rather explicitly leaves the regulatory approach to the agency's expertise and discretion. See 75 FR at 74173 n. 36. Considering the factors described in the NPRM and in Sections III and IV below, NHTSA continues to believe that the separate regulation of engines and vehicles is both consistent with the agency's statutory mandate to determine how to implement a regulatory program designed to achieve the maximum feasible improvement and facilitates coordination with EPA's efforts to reduce greenhouse gas emissions. The Clean Air act, of course, mandates standards for both “new motor vehicles” and “new motor vehicle engines”, so there is no issue of authority for separate engine standards under the EPA GHG program. CAA section 202(a)(1).

As described elsewhere in this preamble, the final standards under the HD National Program address the complete vehicle, to the extent practicable and appropriate under the agencies' respective statutory authorities, through complementary engine and vehicle standards. The agencies continue to believe that this complementary engine and vehicle approach is the best way to achieve near term reductions from the heavy-duty sector. However, we also recognize as did the NAS committee and a wide range of industry and environmental commenters, that in order to fully capture the multi-faceted synergistic aspects of engine and vehicle design a more comprehensive complete vehicle standard may be appropriate in the future. The agencies are committed to fully exploring such a possibility and to developing the testing and modeling tools necessary to enable such a regulatory approach. We intend to work with all interested stakeholders as we move forward.

(1) Brief Overview of the Heavy-Duty Truck Industry

The heavy-duty truck sector spans a wide range of vehicles with often unique form and function. A primary indicator of the extreme diversity among heavy-duty trucks is the range of load-carrying capability across the industry. The heavy-duty truck sector is often subdivided by vehicle weight classifications, as defined by the vehicle's gross vehicle weight rating (GVWR), which is a measure of the combined curb (empty) weight and cargo carrying capacity of the truck. [23] Table I-2 below outlines the vehicle weight classifications commonly used for many years for a variety of purposes by businesses and by several federal agencies, including the Department of Transportation, the Environmental Protection Agency, the Department of Commerce, and the Internal Revenue Service.

Table I-2—Vehicle Weight Classification Back to Top
Class 2b 3 4 5 6 7 8
GVWR (lb) 8,501-10,000 10,001-14,000 14,001-16,000 16,001-19,500 19,501-26,000 26,001-33,000 > 33,001

In the framework of these vehicle weight classifications, the heavy-duty truck sector refers to Class 2b through Class 8 vehicles and the engines that power those vehicles. [24] Unlike light-duty vehicles, which are primarily used for transporting passengers for personal travel, heavy-duty vehicles fill much more diverse operator needs. Heavy-duty pickup trucks and vans (Classes 2b and 3) are used chiefly as work truck and vans, and as shuttle vans, as well as for personal transportation, with an average annual mileage in the range of 15,000 miles. The rest of the heavy-duty sector is used for carrying cargo and/or performing specialized tasks. “Vocational” vehicles, which may span Classes 2b through 8, vary widely in size, including smaller and larger van trucks, utility “bucket” trucks, tank trucks, refuse trucks, urban and over-the-road buses, fire trucks, flat-bed trucks, and dump trucks, among others. The annual mileage of these trucks is as varied as their uses, but for the most part tends to fall in between heavy-duty pickups/vans and the large combination tractors, typically from 15,000 to 150,000 miles per year, although some travel more and some less. Class 7 and 8 combination tractor-trailers—some equipped with sleeper cabs and some not—are primarily used for freight transportation. They are sold as tractors and sometimes run without a trailer in between loads, but most of the time they run with one or more trailers that can carry up to 50,000 pounds or more of payload, consuming significant quantities of fuel and producing significant amounts of GHG emissions. The combination tractor-trailers used in combination applications can travel more than 150,000 miles per year.

EPA and NHTSA have designed our respective standards in careful consideration of the diversity and complexity of the heavy-duty truck industry, as discussed next.

(2) Summary of Final EPA GHG Emission Standards and NHTSA Fuel Consumption Standards

As described above, NHTSA and EPA recognize the importance of addressing the entire vehicle in reducing fuel consumption and GHG emissions. At the same time, the agencies understand that the complexity of the industry means that we will need to use different approaches to achieve this goal, depending on the characteristics of each general type of truck. We are therefore dividing the industry into three discrete regulatory categories for purposes of setting our respective standards—combination tractors, heavy-duty pickups and vans, and vocational vehicles—based on the relative degree of homogeneity among trucks within each category. For each regulatory category, the agencies are adopting related but distinct program approaches reflecting the specific challenges that we see in these segments. In the following paragraphs, we discuss EPA's final GHG emission standards and NHTSA's final fuel consumption standards for the three regulatory categories of heavy-duty vehicles and their engines.

The agencies are adopting test metrics that express fuel consumption and GHG emissions relative to the most important measures of heavy-duty truck utility for each segment, consistent with the recommendation of the 2010 NAS Report that metrics should reflect and account for the work performed by various types of HD vehicles. This approach differs from NHTSA's light-duty program that uses fuel economy as the basis. The NAS committee discussed the difference between fuel economy (a measure of how far a vehicle will go on a gallon of fuel) and fuel consumption (the inverse measure, of how much fuel is consumed in driving a given distance) as potential metrics for MD/HD regulations. The committee concluded that fuel economy would not be a good metric for judging the fuel efficiency of a heavy-duty vehicle, and stated that NHTSA should instead consider fuel consumption as the metric for its standards. As a result, for heavy-duty pickup trucks and vans, EPA and NHTSA are finalizing standards on a per-mile basis (g/mile for the EPA standards, gallons/100 miles for the NHTSA standards), as explained in Section 0 below. For heavy-duty trucks, both combination and vocational, the agencies are adopting standards expressed in terms of the key measure of freight movement, tons of payload miles or, more simply, ton-miles. Hence, for EPA the final standards are in the form of the mass of emissions from carrying a ton of cargo over a distance of one mile (g/ton-mi). Similarly, the final NHTSA standards are in terms of gallons of fuel consumed over a set distance (one thousand miles), or gal/1,000 ton-mile. Finally, for engines, EPA is adopting standards in the form of grams of emissions per unit of work (g/bhp-hr), the same metric used for the heavy-duty highway engine standards for criteria pollutants today. Similarly, NHTSA is finalizing standards for heavy-duty engines in the form of gallons of fuel consumption per 100 units of work (gal/100 bhp-hr).

Section II below discusses the final EPA and NHTSA standards in greater detail.

(a) Class 7 and 8 Combination Tractors

Class 7 and 8 combination tractors and their engines contribute the largest portion of the total GHG emissions and fuel consumption of the heavy-duty sector, approximately 65 percent, due to their large payloads, their high annual miles traveled, and their major role in national freight transport. [25] These vehicles consist of a cab and engine (tractor or combination tractor) and a detachable trailer. In general, reducing GHG emissions and fuel consumption for these vehicles will involve improvements in aerodynamics and tires and reduction in idle operation, as well as engine-based efficiency improvements.

In general, the heavy-duty combination tractor industry consists of tractor manufacturers (which manufacture the tractor and purchase and install the engine) and trailer manufacturers. These manufacturers are usually not the same entity. We are not aware of any manufacturer that typically assembles both the finished truck and the trailer and introduces the combination into commerce for sale to a buyer. The owners of trucks and trailers are often distinct as well. A typical truck buyer will purchase only the tractor. The trailers are usually purchased and owned by fleets and shippers. This occurs in part because trucking fleets on average maintain 3 trailers per tractor and in some cases as many as 6 or more trailers per tractor. There are also large differences in the kinds of manufacturers involved with producing tractors and trailers. For HD highway tractors and their engines, a relatively limited number of manufacturers produce the vast majority of these products. The trailer manufacturing industry is quite different, and includes a large number of companies, many of which are relatively small in size and production volume. Setting standards for the products involved—tractors and trailers—requires recognition of the large differences between these manufacturing industries, which can then warrant consideration of different regulatory approaches.

Based on these industry characteristics, EPA and NHTSA believe that the most straightforward regulatory approach for combination tractors and trailers is to establish standards for tractors separately from trailers. As discussed below in Section IX, the agencies are adopting standards for the tractors and their engines in this rulemaking, but did not propose and are not adopting standards for trailers.

As with the other regulatory categories of heavy-duty vehicles, EPA and NHTSA have concluded that achieving reductions in GHG emissions and fuel consumption from combination tractors requires addressing both the cab and the engine, and EPA and NHTSA each are adopting standards that reflect this conclusion. The importance of the cab is that its design determines the amount of power that the engine must produce in moving the truck down the road. As illustrated in Figure I-1, the loads that require additional power from the engine include air resistance (aerodynamics), tire rolling resistance, and parasitic losses (including accessory loads and friction in the drivetrain). The importance of the engine design is that it determines the basic GHG emissions and fuel consumption performance of the engine for the variety of demands placed on the engine, regardless of the characteristics of the cab in which it is installed. The agencies intend for the final standards to result in the application of improved technologies for lower GHG emissions and fuel consumption for both the cab and the engine.

Accordingly, for Class 7 and 8 combination tractors, the agencies are each finalizing two sets of standards. For vehicle-related emissions and fuel consumption, tractor manufacturers are required to meet vehicle-based standards. Compliance with the vehicle standard will typically be determined based on a customized vehicle simulation model, called the Greenhouse gas Emissions Model (GEM), which is consistent with the NAS Report recommendations to require compliance testing for combination tractors using vehicle simulation rather than chassis dynamometer testing. This compliance model was developed by EPA specifically for this final action. It is an accurate and cost-effective alternative to measuring emissions and fuel consumption while operating the vehicle on a chassis dynamometer. Instead of using a chassis dynamometer as an indirect way to evaluate real-world operation and performance, various characteristics of the vehicle are measured and these measurements are used as inputs to the model. These characteristics relate to key technologies appropriate for this subcategory of truck—including aerodynamic features, weight reductions, tire rolling resistance, the presence of idle-reducing technology, and vehicle speed limiters. The model also assumes the use of a representative typical engine, rather than a vehicle-specific engine, because engines are regulated separately. Using these inputs, the model will be used to quantify the overall performance of the vehicle in terms of CO 2 emissions and fuel consumption. The model's development and design, as well as the sources for inputs, are discussed in detail in Section II below and in Chapter 4 of the RIA.

(i) Final Standards for Class 7 and 8 Combination Tractors and Their Engines

The vehicle standards that EPA and NHTSA are adopting for Class 7 and 8 combination tractor manufacturers are based on several key attributes related to GHG emissions and fuel consumption that we believe reasonably represent the many differences in utility and performance among these vehicles. The final standards differ depending on GVWR (i.e., whether the truck is Class 7 or Class 8), the height of the roof of the cab, and whether it is a “day cab” or a “sleeper cab.” These later two attributes are important because the height of the roof, designed to correspond to the height of the trailer, significantly affects air resistance, and a sleeper cab generally corresponds to the opportunity for extended duration idle emission and fuel consumption improvements. We received a number of comments supporting this approach and no comments that provided a compelling reason to change our approach in this final action.

Thus, the agencies have created nine subcategories within the Class 7 and 8 combination tractor category based on the differences in expected emissions and fuel consumption associated with the key attributes of GVWR, cab type, and roof height. The agencies are setting standards beginning in 2014 model year with more stringent standards following in 2017 model year. Table I-3 presents the agencies' respective standards for combination tractor manufacturers for the 2017 model year. The standards represent an overall fuel consumption and CO 2 emissions reduction up to 23 percent from the tractors and the engines installed in them when compared to a baseline 2010 model year tractor and engine without idle shutdown technology. The standard values shown below differ somewhat from the proposal, reflecting refinements made to the GEM in response to comments. These changes did not impact our estimates of the relative effectiveness of the various control technologies modeled in this final action nor the overall cost or benefits or cost effectiveness estimated for these final vehicle standards.

As proposed, the agencies are exempting certain types of tractors which operate off-road to be exempt from the combination tractor vehicle standards (although standards would still apply to the engines installed in these vehicles). The criteria for tractors to be considered off-road have been amended slightly from those proposed, in response to public comment. The agencies have also recognized, again in response to public comment, that some combination tractors operate in a manner essentially the same as vocational vehicles and have created a subcategory of “vocational tractors” as a result. Vocational tractors will be subject to the standards for vocational vehicles rather than the combination tractor standards. See Section II.B of this preamble.

Table I-3—Heavy-Duty Combination Tractor EPA Emissions Standards (G CO 2/Ton-Mile) and NHTSA Fuel Consumption Standards (GAL/1,000 Ton-Mile) Back to Top
Day cab Sleeper cab
Class 7 Class 8 Class 8
2017 Model Year CO 2 Grams per Ton-Mile      
Low Roof 104 80 66
Mid Roof 115 86 73
High Roof 120 89 72
2017 Model Year Gallons of Fuel per 1,000 Ton-Mile      
Low Roof 10.2 7.8 6.5
Mid Roof 11.3 8.4 7.2
High Roof 11.8 8.7 7.1

In addition, the agencies are finalizing separate performance standards for the engines manufactured for use in these trucks. EPA's engine-based CO 2 standards and NHTSA's engine-based fuel consumption standards are implemented using EPA's existing test procedures and regulatory structure for criteria pollutant emissions from medium- and heavy-duty engines. As at proposal, the final engine standards vary depending on engine size linked to intended vehicle service class. Consistent with our proposal, the agencies are finalizing an interim alternative compression ignition engine standard for model years 2014-2016. This alternative standard is designed to provide a glide path for legacy diesel engine products that may not be able to comply with the final engine standards for model years 2014-16 given the short (approximately 2-year) lead time of this program. We believe this alternative standard is appropriate for a first-ever program when the overall baseline performance of the industry is quite varied and where the short lead time means that not every product can be brought into compliance by 2014. The alternative standard only applies through and including model year 2016.

Separately, EPA is adopting standards for combination tractors that apply in use. EPA is also finalizing engine-based N 2 O and CH 4 standards for manufacturers of the engines used in these combination tractors. EPA is finalizing separate engine-based standards for N 2 O and CH 4 because the agency believes that emissions of these GHGs are technologically related solely to the engine, fuel, and emissions aftertreatment systems, and the agency is not aware of any influence of vehicle-based technologies on these emissions. NHTSA is not incorporating standards for N 2 O and CH 4 because these emissions do not impact fuel consumption in a significant way. The standards that EPA is finalizing for N 2 O and CH 4 are less stringent than those we proposed, reflecting new data provided to EPA in comments on the proposal showing that the current baseline level of N 2 O and CH 4 emissions varies more than EPA had expected. EPA expects that manufacturers of current engine technologies will be able to comply with the final N 2 O and CH 4“cap” standards with little or no technological improvements; the value of the standards will be to prevent significant increases in these emissions as alternative technologies are developed and introduced in the future. Compliance with the final EPA engine-based CO 2 standards and the final NHTSA engine-based fuel consumption standards, as well as the final EPA N 2 O and CH 4 standards, will be determined using the appropriate EPA engine test procedure, as discussed in Sections II.B, II.D, and II.E below.

As with the other categories of heavy-duty vehicles, EPA and NHTSA are finalizing respective standards that will apply to Class 7 and 8 tractors at the time of production (as in Table I-3, above). In addition, EPA is finalizing separate standards that will apply for a specified period of time in use. All of the standards for these vehicles, as well as details about the provisions for certification and implementation of these standards, are discussed in more detail in Sections II, III, IV, and V below and in the RIA.

(ii) EPA's Final Air Conditioning Leakage Standard for Class 7 and 8 Combination Tractors

In addition to the final EPA tractor- and engine-based standards for CO 2 and engine-based standards for N 2 O, and CH 4 emissions, EPA is finalizing a separate standard to reduce leakage of HFC refrigerant from cabin air conditioning (A/C) systems from combination tractors, to apply to the tractor manufacturer. This standard is independent of the CO 2 tractor standard, as discussed below in Section II.E.5. Because the current refrigerant used widely in all these systems has a very high global warming potential, EPA is concerned about leakage of refrigerant. [27]

Because the interior volume to be cooled for most tractor cabins is similar to that of light-duty vehicles, the size and design of current tractor A/C systems is also very similar. The compliance approach for Class 7 and 8 tractors is therefore similar to that in the light-duty rule in that these standards are design-based. Manufacturers will choose technologies from a menu of leak-reducing technologies sufficient to comply with the standard, as opposed to using a test to measure performance.

However, the final heavy-duty A/C provisions differ in two important ways from those established in the light-duty rule. First, the light-duty provisions were established as voluntary ways to generate credits towards the CO 2 g/mi standard, and EPA took into account the expected use of such credits in determining the stringency of the CO 2 emissions standards. In the HD National Program, EPA is requiring that manufacturers actually meet a standard—as opposed to having the opportunity to earn a credit—for A/C refrigerant leakage. Thus, refrigerant leakage control is not separately accounted for in the final heavy-duty CO 2 standards. We are taking this approach here recognizing that while the benefits of leakage control are almost identical between light-duty and heavy-duty vehicles on a per vehicle basis, these benefits on a per mile basis expressed as a percentage of overall GHG emissions are much smaller for heavy-duty vehicles due to their much higher CO 2 emissions rates and higher annual mileage when compared to light-duty vehicles. Hence a credit-based approach as done for light-duty vehicles would provide less motivation for manufacturers to install low leakage systems even though such systems represent a highly cost effective means to control GHG emissions. The second difference relates to the expression of the leakage rate. The light-duty A/C leakage standard is expressed in terms of grams per year. For EPA's heavy-duty program, however, because of the wide variety of system designs and arrangements, a one-size-fits-all gram per year standard would not be appropriate, so EPA is adopting a standard in terms of annual mass leakage rate for A/C systems with refrigerant capacities less than or equal to 733 grams and percent of total refrigerant leakage per year for A/C systems with refrigerant capacities greater than 733 grams. The percent of total refrigerant leakage per year requires the total refrigerant capacity of the A/C system to be taken into account in determining compliance. EPA believes that this approach—a standard instead of a credit, and basing the standard on percent or mass of leakage over time—is more appropriate for heavy-duty tractors than the light-duty vehicle approach and that it will achieve the desired reductions in refrigerant leakage. Compliance with the standard will be determined through a showing by the tractor manufacturer that its A/C system incorporates a combination of low-leak technologies sufficient to meet the leakage rate of the applicable standard. The “menu” of technologies is very similar to that established in the light-duty 2012-2016 MY vehicle rule. [28]

Finally, the agencies did not propose and are not adopting an A/C system efficiency standard in this heavy-duty rulemaking, although an efficiency credit was a part of the light-duty rule. The much larger emissions of CO 2 from a heavy-duty tractor as compared to those from a light-duty vehicle mean that the relative amount of CO 2 that could be reduced through A/C efficiency improvements is very small.

A more detailed discussion of A/C related issues is found in Section II.E.5 of this preamble.

(b) Heavy-Duty Pickup Trucks and Vans (Class 2b and 3)

Heavy-duty vehicles with GVWR between 8,501 and 10,000 lb are classified in the industry as Class 2b motor vehicles per the Federal Motor Carrier Safety Administration definition. As discussed above, Class 2b includes MDPVs that are regulated by the agencies under the light-duty vehicle rule, and the agencies are not adopting additional requirements for MDPVs in this rulemaking. Heavy-duty vehicles with GVWR between 10,001 and 14,000 lb are classified as Class 3 motor vehicles. Class 2b and Class 3 heavy-duty vehicles (referred to in these rules as “HD pickups and vans”) together emit about 15 percent of today's GHG emissions from the heavy-duty vehicle sector.

About 90 percent of HD pickups and vans are3/4-ton and 1-ton pickup trucks, 12- and 15-passenger vans, and large work vans that are sold by vehicle manufacturers as complete vehicles, with no secondary manufacturer making substantial modifications prior to registration and use. These vehicle manufacturers are companies with major light-duty markets in the United States, primarily Ford, General Motors, and Chrysler. Furthermore, the technologies available to reduce fuel consumption and GHG emissions from this segment are similar to the technologies used on light-duty pickup trucks, including both engine efficiency improvements (for gasoline and diesel engines) and vehicle efficiency improvements.

For these reasons, EPA believes it is appropriate to adopt GHG standards for HD pickups and vans based on the whole vehicle (including the engine), expressed as grams per mile, consistent with the way these vehicles are regulated by EPA today for criteria pollutants. NHTSA believes it is appropriate to adopt corresponding gallons per 100 mile fuel consumption standards that are likewise based on the whole vehicle. This complete vehicle approach being adopted by both agencies for HD pickups and vans is consistent with the recommendations of the NAS Committee in their 2010 Report. EPA and NHTSA also believe that the structure and many of the detailed provisions of the recently finalized light-duty GHG and fuel economy program, which also involves vehicle-based standards, are appropriate for the HD pickup and van GHG and fuel consumption standards as well, and this is reflected in the standards each agency is finalizing, as detailed in Section II.C. These commonalities include a new vehicle fleet average standard for each manufacturer in each model year and the determination of these fleet average standards based on production volume-weighted targets for each model, with the targets varying based on a defined vehicle attribute. Vehicle testing will be conducted on chassis dynamometers using the drive cycles from the EPA Federal Test Procedure (Light-duty FTP or “city” test) and Highway Fuel Economy Test (HFET or “highway” test). [29]

For the light-duty GHG and fuel economy standards, the agencies factored in vehicle size by basing the emissions and fuel economy targets on vehicle footprint (the wheelbase times the average track width). [30] For those standards, passenger cars and light trucks with larger footprints are assigned higher GHG and lower fuel economy target levels in acknowledgement of their inherent tendency to consume more fuel and emit more GHGs per mile. For HD pickups and vans, the agencies believe that setting standards based on vehicle attributes is appropriate, but feel that a work-based metric serves as a better attribute than the footprint attribute utilized in the light-duty vehicle rulemaking. Work-based measures such as payload and towing capability are key among the parameters that characterize differences in the design of these vehicles, as well as differences in how the vehicles will be utilized. Buyers consider these utility-based attributes when purchasing a heavy-duty pickup or van. EPA and NHTSA are therefore finalizing standards for HD pickups and vans based on a “work factor” attribute that combines their payload and towing capabilities, with an added adjustment for 4-wheel drive vehicles. The agencies received a number of comments supporting this approach arguing, as the agencies had, that this approach was an effective way to encourage technology development and to appropriately reflect the utility of work vehicles while setting a consistent metric measure of vehicle performance.

As proposed, the agencies are adopting provisions such that each manufacturer's fleet average standard will be based on production volume-weighting of target standards for all vehicles that in turn are based on each vehicle's work factor. These target standards are taken from a set of curves (mathematical functions), presented in Section II.C below and in § 1037.104. EPA is also phasing in the CO 2 standards gradually starting in the 2014 model year, at 15-20-40-60-100 percent of the model year 2018 standards stringency level in model years 2014-2015-2016-2017-2018, respectively. The phase-in takes the form of a set of target standard curves, with increasing stringency in each model year, as detailed in Section II.C. The final EPA standards for 2018 (including a separate standard to control air conditioning system leakage) represent an average per-vehicle reduction in GHGs of 17 percent for diesel vehicles and 12 percent for gasoline vehicles, compared to a common baseline, as described in Sections II.C and III.B of this preamble. The rule contains separate standards for diesel and gasoline heavy duty pickups and vans for reasons described in Section II.C below. EPA is also finalizing a compliance alternative whereby manufacturers can phase in different percentages: 15-20-67-67-67-100 percent of the model year 2019 standards stringency level in model years 2014-2015-2016-2017-2018-2019, respectively. This compliance alternative parallels and is equivalent to NHTSA's first alternative described below.

NHTSA is allowing manufacturers to select one of two fuel consumption standard alternatives for model years 2016 and later. The first alternative defines individual gasoline vehicle and diesel vehicle fuel consumption target curves that will not change for model years 2016-2018, and are equivalent to EPA's 67-67-67-100 percent target curves in model years 2016-2017-2018-2019, respectively. The target curves for this alternative are presented in Section II.C. The second alternative uses target curves that are equivalent to the EPA's 40-60-100 percent target curves in model years 2016-2017-2018, respectively. Stringency for the alternatives has been selected to allow a manufacturer, through the use of the credit and deficit carry-forward provisions that the agencies are also finalizing, to rely on the same product plans to satisfy either of these two alternatives, and also EPA requirements. If a manufacturer cannot meet an applicable standard in a given model year, it may make up its shortfall by overcomplying in a subsequent year, called reconciling a credit deficit. NHTSA is also allowing manufacturers to voluntarily opt into the NHTSA HD pickup and van program in model years 2014 or 2015. For these model years, NHTSA's fuel consumption target curves are equivalent to EPA's target curves.

The agencies received a number of comments including from the Senate authors and supporters of the Ten-in-Ten Fuel Economy Act suggesting that the standards for heavy-duty pickups and vans should be made more stringent for gasoline vehicles and that the phase-in timing of the standards should be accelerated to the 2016 model year (from 2018). We also received comments arguing that the proposed standards were aggressive and could only be met given the phase-in schedules proposed by the agencies. In response to these comments, we reviewed again the technology assessments from the 2010 NAS report, our own joint light-duty 2012-2016 rulemaking, and information provided by the commenters relevant to the stringency of these standards. After reviewing all of the information, we continue to conclude that the proposed standards and associated phase-in schedules represent technically stringent but reasonable standards considering the available lead time and costs to bring the necessary technologies to market and our own assessments of the efficacy of the technologies when applied to heavy-duty pickup trucks and vans. Further detail on the feasibility of the standards and the agencies' choices among alternative standards is found in Section III.C below.

The Senate authors and supporters of the Ten-in-Ten Fuel Economy Act sent a letter to the agencies encouraging the agencies to finalize a fuel economy labeling requirement for heavy-duty pickups and vans. [31] The agencies recognize that consumer information in the form of a fuel efficiency label can be a valuable tool to help achieve our goals, and we note that the agencies have just recently finalized a new fuel economy label for passenger cars and light trucks. See 76 FR at 39478. That rulemaking effort focused solely on modifying an existing label and was a multi-year process with significant public input. As we did not propose a consumer label for heavy-duty pickups and vans in this action and have not appropriately engaged the public in developing such a label, we are not prepared to finalize a consumer-based label in this action. However, we do intend to consider this issue as we begin work on the next phase of regulations, as we recognize that a consumer label can play an important role in reducing fuel consumption and GHG emissions.

The form and stringency of the EPA and NHTSA standards curves are based on a set of vehicle, engine, and transmission technologies expected to be used to meet the recently established GHG emissions and fuel economy standards for model year 2012-2016 light-duty vehicles, with full consideration of how these technologies are likely to perform in heavy-duty vehicle testing and use. All of these technologies are already in use or have been announced for upcoming model years in some light-duty vehicle models, and some are in use in a portion of HD pickups and vans as well. The technologies include:

  • Advanced 8-speed automatic transmissions.
  • Aerodynamic improvements.
  • Electro-hydraulic power steering.
  • Engine friction reductions.
  • Improved accessories.
  • Low friction lubricants in powertrain components.
  • Lower rolling resistance tires.
  • Lightweighting.
  • Gasoline direct injection.
  • Diesel aftertreatment optimization.
  • Air conditioning system leakage reduction (for EPA program only).

See Section III.B for a detailed analysis of these and other potential technologies, including their feasibility, costs, and effectiveness when employed for reducing fuel consumption and CO 2 emissions in HD pickups and vans.

A relatively small number of HD pickups and vans are sold by vehicle manufacturers as incomplete vehicles, without the primary load-carrying device or container attached. We are generally regulating these vehicles as Class 2b through 8 vocational vehicles but are also allowing manufacturers the option to choose to comply with heavy-duty pickup or van standards, as described in Section I.C.(2)(c). Although, as with vocational vehicles generally, we have little information on baseline aerodynamic performance and opportunities for improvement, a sizeable subset of these incomplete vehicles, often called cab-chassis vehicles, are sold by the vehicle manufacturers in configurations with many of the components that affect GHG emissions and fuel consumption identical to those on complete pickup truck or van counterparts—including engines, cabs, frames, transmissions, axles, and wheels. We are including provisions that will allow manufacturers to include these vehicles, as well as some Class 4 and 5 vehicles, to be regulated under the chassis-based HD pickup and van program (i.e. subject to the standards for HD pickups and vans), rather than the vocational vehicle program. These provisions are described in Section V.B(1)(e).

In addition to the EPA CO 2 emission standards and the NHTSA fuel consumption standards for HD pickups and vans, EPA is also finalizing standards for two additional GHGs, N 2 O and CH 4, as well as standards for air conditioning-related HFC emissions. These standards are discussed in more detail in Section II.E. Finally, EPA is finalizing standards that will apply to HD pickups and vans in use. All of the standards for these HD pickups and vans, as well as details about the provisions for certification and implementation of these standards, are discussed in Section II.C.

(c) Class 2b-8 Vocational Vehicles

Class 2b-8 vocational vehicles consist of a wide variety of vehicle types. Some of the primary applications for vehicles in this segment include delivery, refuse, utility, dump, and cement trucks; transit, shuttle, and school buses; emergency vehicles, motor homes, [32] tow trucks, among others. These vehicles and their engines contribute approximately 20 percent of today's heavy-duty truck sector GHG emissions.

Manufacturing of vehicles in this segment of the industry is organized in a more complex way than that of the other heavy-duty categories. Class 2b-8 vocational vehicles are often built as a chassis with an installed engine and an installed transmission. Both the engine and transmissions are typically manufactured by other manufacturers and the chassis manufacturer purchases and installs them. Many of the same companies that build Class 7 and 8 tractors are also in the Class 2b-8 chassis manufacturing market. The chassis is typically then sent to a body manufacturer, which completes the vehicle by installing the appropriate feature—such as dump bed, delivery box, or utility bucket—onto the chassis. Vehicle body manufacturers tend to be small businesses that specialize in specific types of bodies or specialized features.

EPA and NHTSA proposed that in this vocational vehicle category the proposed GHG and fuel consumption standards apply to chassis manufacturers. Chassis manufacturers play a central role in the manufacturing process. The product they produce—the chassis with engine and transmission—includes the primary technologies that affect GHG emissions and fuel consumption. They also constitute a much more limited group of manufacturers for purposes of developing and implementing a regulatory program. The agencies believe that a focus on the body manufacturers would be much less practical, since they represent a much more diverse set of manufacturers, many of whom are small businesses. Further, the part of the vehicle that they add affords very few opportunities to reduce GHG emissions and fuel consumption (given the limited role that aerodynamics plays in many types of lower speed and stop-and-go operation typically found with vocational vehicles.) Therefore, the agencies proposed that the standards in this vocational vehicle category would apply to the chassis manufacturers of all heavy-duty vehicles not otherwise covered by the HD pickup and van standards or Class 7 and 8 combination tractor standards discussed above. The agencies requested comment on the proposed focus on chassis manufacturers.

Volvo and Daimler commented that the EISA does not speak to the regulation of subsystems, such as engines or incomplete vehicles, and argued that on the other hand, Section 32902(k)(2) prescribes the regulation of vehicles. Volvo further stated that precedent for the regulation of complete vehicles exists in the light-duty fuel economy rule. As noted above, NHTSA does not believe that EISA mandates a particular regulatory approach, but rather gives the agency wide latitude and explicitly leaves that determination to the agency. NHTSA also notes that its heavy-duty rule creates a new fuel efficiency program for which the light-duty program does not necessarily serve as a useful precedent for considerations of its structure. Unlike the light-duty fuel economy program, MD/HD vehicles are produced in widely diverse stages. Further, given the MD/HD market structure, where the complete vehicle manufacturers are numerous, diverse, and often small businesses, the regulation of complete vehicles would create unique difficulties for the application of appropriate and feasible technologies. These same considerations justify EPA's determination, pursuant to CAA section 202 (a), to regulate only chassis manufacturers in this first stage of GHG rules for the heavy-duty sector. NHTSA also notes that this rule does not represent the first time that the agency has regulated incomplete vehicles. Rather, incomplete vehicles have a history of regulation under the Federal Motor Vehicle Safety Standards. [33] For this first phase of the HD National Program, NHTSA and EPA believe that given the complexity of the manufacturing process for vocational vehicles, and given the wide range of entities that participate in that process, vehicle fuel consumption standards would be most appropriately applied to chassis manufacturers and not to body builders.

The agencies continue to believe that regulation of the chassis manufacturers for this vocational vehicle category will achieve the maximum feasible improvement in fuel efficiency for purposes of EISA and appropriate emissions reductions for purposes of the CAA. Therefore, consistent with our proposal the final standards in this vocational vehicle category apply to the chassis manufacturers of all heavy-duty vehicles not otherwise covered by the HD pickup and van standards or Class 7 and 8 combination tractor standards discussed above. As discussed above, EPA and NHTSA have concluded that reductions in GHG emissions and fuel consumption require addressing both the vehicle and the engine. As discussed above for Class 7 and 8 combination tractors, the agencies are each finalizing two sets of standards for Class 2b-8 vocational vehicles. For vehicle-related emissions and fuel consumption, the agencies are adopting standards for chassis manufacturers: EPA CO 2 (g/ton-mile) standards and NHTSA fuel consumption (gal/1,000 ton-mile) standards). While the agencies believe that a freight-based metric is broadly appropriate for vocational vehicles because the vocational vehicle population is dominated by freight trucks and maintain that it is appropriate for the first phase of the program, the agencies may consider other metrics for future phases of a HD program. Manufacturers will use GEM, the same customized vehicle simulation model used for Class 7 and 8 tractors, to determine compliance with the vocational vehicle standards finalized in this action. The primary manufacturer-generated input into the GEM for this category of trucks will be a measure of tire rolling resistance, as discussed further below, because tire improvements are the primary means of vehicle improvement available at this time for vocational vehicles. The model also assumes the use of a typical representative, compliant engine in the simulation, resulting in an overall value for CO 2 emissions and one for fuel consumption. This is done for the same reason as for combination tractors. As is the case for combination tractors, the manufacturers of the engines intended for vocational vehicles will be subject to separate engine-based standards.

(i) Final Standards for Class 2b-8 Vocational Vehicles and Their Engines

Based on our analysis and research, the agencies believe that the primary opportunity for reductions in vocational vehicle GHG emissions and fuel consumption will be through improved engine technologies and improved tire rolling resistance. For engines, EPA and NHTSA are adopting separate standards for the manufacturers of engines used in Class 2b-8 vocational vehicles (the same approach as for combination tractors and engines intended for use in those tractors). EPA's final engine-based CO 2 standards and NHTSA's final engine-based fuel consumption standards vary based on the expected weight class and usage of the truck into which the engine will be installed. Tire rolling resistance is closely related to the weight of the vehicle. Therefore, we are adopting vehicle-based standards for these trucks which vary according to one key attribute, GVWR. For this initial HD rulemaking, we are adopting standards based on the same groupings of truck weight classes used for the engine standards—light heavy-duty, medium heavy-duty, and heavy heavy-duty. These groupings are appropriate for the final vehicle-based standards because they parallel the general divisions among key engine characteristics, as discussed in Section II.

The agencies are also finalizing an interim alternative compression ignition (diesel) engine standard for model years 2014-2016, again analogous to the alternative standards for compression ignition engines use in combination tractors. The need for this provision and our considerations in adopting it are the same for the engines used in vocational vehicles as for the engines used in combination tractors. As we proposed, these alternative standards will only be available through model year 2016. In addition, manufacturers that use the interim alternative diesel engine standards for model years 2014-2016 under the EPA program must use equivalent fuel consumption standards under the NHTSA program.

For the 2014 to 2016 model years, manufacturers may also choose to meet alternative engine standards that are phased-in over the model years to coincide with new EPA On-Board Diagnostic (OBD) requirements applicable for these same model years. See Sections II.B and II.D below.

The agencies received a significant number of comments including from the Senate authors and supporters of the Ten-in-Ten Fuel Economy Act arguing that our proposed standards for vocational vehicles did not reflect all of the technologies identified in the 2010 NAS report. The commenters encouraged the agencies to expand the program to bring in additional reductions through the use of new transmission technologies, vehicle weight reductions and hybrid drivetrains. In general, the agencies agree with the commenters' central contention that there are additional technologies to improve the fuel efficiency of vocational vehicles. As discussed later, we are finalizing provisions to allow new technologies to be brought into the program through the innovative technology credit program. More specifically, we are including provisions to account for and credit the use of hybrid technology as a technology that can reduce emissions and fuel consumption. Hybrid technology can currently be a cost-effective technology in certain specific vocational applications, and the agencies want to recognize and promote the use of this technology. (See Sections I.E and IV below.) However, we are not finalizing standards that are premised on the use of these additional technologies because we have not been able to develop the test procedures, regulatory mechanisms and baseline performance data necessary to adopt a more comprehensive approach to controlling fuel efficiency and GHG emissions from vocational vehicles. In concept, the agencies would need to know the baseline weight, aerodynamic performance, and transmission configuration for the wide range of vocational vehicles produced today. We do not have this information even for relatively small portions of this market (e.g. concrete mixers) nor are we well informed regarding the potential tradeoffs to changes to vehicle utility that might exist for changes to concrete mixer designs in response to a regulation. Nor did the commenters provide any such information. Absent this information and the necessary regulatory tools, we believe the standards we are finalizing for vocational vehicles represent the most appropriate standards for this segment during the model years of the first phase of the program. We intend to address fuel consumption and GHG emissions from these vehicles in a more comprehensive manner through future regulation and look forward to working with all stakeholders on this important segment in the future.

The agencies are setting standards beginning in the 2014 model year and establishing more stringent standards in the 2017 model year. Table I-4 presents EPA's final CO 2 standards and NHTSA's final fuel consumption standards for chassis manufacturers of Class 2b through Class 8 vocational vehicles for the 2017 model year. The 2017 model year standards represent a 6 to 9 percent reduction in CO 2 emissions and fuel consumption over a 2010 model year vehicle.

Table I-4—Final 2017 Class 2 b-8 Vocational Vehicle EPA CO 2 Standards and NHTSA Fuel Consumption Standards Back to Top
Light heavy-duty Class 2b-5 Medium heavy-duty Class 6-7 Heavy heavy-duty Class 8
EPA CO 2 (gram/ton-mile) Standard Effective 2017 Model Year      
CO 2 Emissions 373 225 222
NHTSA Fuel Consumption (gallon per 1,000 ton-mile) Standard Effective 2017 Model Year      
Fuel Consumption 36.7 22.1 21.8

As mentioned above for Class 7 and 8 combination tractors, EPA believes that N 2 O and CH 4 emissions are technologically related solely to the engine, fuel, and emissions aftertreatment systems, and the agency is not aware of any influence of vehicle-based technologies on these emissions. Therefore, for Class 2b-8 vocational vehicles, EPA's final N 2 O and CH 4 standards cover manufacturers of the engines to be used in vocational vehicles. EPA did not propose, nor are we adopting separate vehicle-based standards for these GHGs. As for the engines used in Class 7 and 8 tractors, we are finalizing a somewhat higher N 2 O and CH 4 emission standards reflecting new data submitted to the agencies during the public comment period. EPA expects that manufacturers of current engine technologies will be able to comply with the final “cap” standards with little or no technological improvements; the value of the standards is that they will prevent significant increases in these emissions as alternative technologies are developed and introduced in the future. Compliance with the final EPA engine-based CO 2 standards and the final NHTSA fuel consumption standards, as well as the final EPA N 2 O and CH 4 standards, will be determined using the appropriate EPA engine test procedure, as discussed in Section II below.

As with the other regulatory categories of heavy-duty vehicles, EPA and NHTSA are adopting standards that apply to Class 2b-8 vocational vehicles at the time of production, and EPA is adopting standards for a specified period of time in use. All of the standards for these trucks, as well as details about the final provisions for certification and implementation of these standards, are discussed in more detail later in this notice and in the RIA.

EPA did not propose, nor is it adopting A/C refrigerant leakage standards for Class 2b-8 vocational vehicles, primarily because of the number of entities involved in their manufacture and thus the potential for different entities besides the chassis manufacturer to be involved in the A/C system production and installation.

(d) What manufacturers are not covered by the final standards?

The NPRM proposed to defer temporarily greenhouse gas emissions and fuel consumption standards for any manufacturers of heavy-duty engines, manufacturers of combination tractors, and chassis manufacturers for vocational vehicles that meet the “small business” size criteria set by the Small Business Administration (SBA). 13 CFR 121.201 defines a small business by the maximum number of employees; for example, this is currently 1,000 for heavy-duty vehicle manufacturing and 750 for engine manufacturing. [34] The agencies stated that they would instead consider appropriate GHG and fuel consumption standards for these entities as part of a future regulatory action. This includes both U.S.-based and foreign small-volume heavy-duty manufacturers. To ensure that the agencies are aware of which companies would be exempt, the agencies proposed to require that such entities submit a declaration describing how it qualifies as a small entity under the provisions of 13 CFR 121.201 to EPA and NHTSA as prescribed in Section V below.

EPA and NHTSA were not aware of any manufacturers of HD pickups and vans that meet these criteria. For each of the other categories and for engines, the agencies identified a small number of manufacturers that would appear to qualify as small businesses under the SBA size criterion, which were estimated to comprise a negligible percentage of the U.S. market. [35] Therefore, the agencies believed that deferring the standards for these companies at this time would have a negligible impact on the GHG emission reductions and fuel consumption reductions that the program would otherwise achieve. The agencies proposed to consider appropriate GHG emissions and fuel consumption standards for these entities as part of a future regulatory action.

The Institute for Policy Integrity (IPI) commented that the small business exemption proposed in the NPRM was based on the improper framework of whether the exemption would have a negligible impact, and did not adequately explain why the regulation of small businesses would face special compliance and administrative burdens. IPI argued that the only proper basis for this exemption would be if the agencies could explain how these burdens create costs that exceeded the benefits of regulation.

NHTSA believes that developing standards that are “appropriate, cost-effective, and technologically feasible” under 49 U.S.C. 32902(k)(2) includes the authority to exclude certain manufacturers if their inclusion would work against these statutory factors. Similarly, under section 202(a) of the CAA, EPA may reasonably choose to defer regulation of industry segments based on considerations of cost, cost-effectiveness and available lead time for standards. As noted above, small businesses make up a very small percentage of the market and are estimated to have a negligible impact on the emissions and fuel consumption goals of this program. The short lead time before the CO 2 standards take effect, the extremely small fuel savings and emissions contribution of these entities, and the potential need to develop a program that would be structured differently for them (which would require more time to determine and adopt), all led to the decision that the inclusion of small businesses would not be appropriate at this time. Therefore, the final rule exempts small businesses as proposed.

Volvo and EMA stated that by exempting small businesses based on the definition from SBA, the rules would create a competitive advantage for small businesses over larger entities. EMA commented that the exemption should not apply to market segments where a small business has a significant share of a particular HD market. Volvo argued that the exempted businesses could expand their product offerings or sell vehicles on behalf of larger entities, thereby inappropriately increasing the scope of the exclusion. The agencies anticipate that the gain a manufacturer might achieve by restructuring its practices and products to circumvent the standard (which for vocational vehicles simply means installing low rolling resistance tires) in the first few years of this program will be outweighed by the costs, particularly as small businesses anticipate their potential inclusion in the next rulemaking.

Volvo also commented that the agencies should elaborate on the requirements for the exemption in greater detail. The agencies agree that this may help to clarify the process. As suggested by Volvo, the agencies will consider affiliations to other companies and evidence of spin-offs for the purpose of circumventing the standards in determining whether a business qualifies as a small entity for this exclusion. Each declaration must be submitted in writing to EPA and NHTSA as prescribed in Section V below. As the agencies gain more experience with this exemption, these clarifications may be codified in the regulatory text of a future rulemaking.

Volvo further commented that the agencies were adopting an exemption of “small businesses” in order to avoid doing a Small Business Regulatory Enforcement Fairness Act (SBREFA) and Regulatory Flexibility Act (RFA) analysis. The agencies would like to reiterate that they have decided not to include small businesses at this time due to the factors described above. The discussion on an RFA analysis is laid out in Section XII(4).

The agencies continue to believe that deferring the standards for these companies at this time will have a negligible impact on the GHG emission reductions and fuel consumption reductions that the program would otherwise achieve. Therefore, the final rules include the small business exemption as proposed. The specific deferral provisions are discussed in more detail in Section II.

The agencies will consider appropriate GHG emissions and fuel consumption standards for these entities as part of a future regulatory action.

(e) Light-Duty Vehicle CH 4 and N 2 O Standards Flexibility

After finalization of the N 2 O and CH 4 standards for light-duty vehicles as part of the 2012-2016 MY program, some manufacturers raised concerns that they may have difficulty meeting those standards across their light-duty vehicle fleets. In response to these concerns, as part of the same Federal Register notice as the heavy-duty proposal, EPA requested comments on additional options for manufacturers to comply with light-duty vehicle N 2 O and CH 4 standards to provide additional near-term flexibility. Commenters providing comment on this issue supported additional flexibility for manufacturers. EPA is finalizing provisions allowing manufacturers to use CO 2 credits, on a CO 2-equivalent basis, to meet the N 2 O and CH 4 standards, which is consistent with many commenters' preferred approach. Manufacturers will have the option of using CO 2 credits to meet N 2 O and CH 4 standards on a test group basis as needed for MYs 2012-2016.

(f) Alternative Fuel Engines and Vehicles

The agencies believe that it is also appropriate to take steps to recognize the benefits of flexible-fueled vehicles (FFVs) and dedicated alternative-fueled vehicles. In the NPRM, EPA proposed to determine the emissions performance of dedicated alternative fuel engines and pickup trucks and vans by measuring tailpipe CO 2 emissions. NHTSA proposed to determine fuel consumption performance of non-electric dedicated alternative fuel engines and pickup trucks and vans by measuring fuel consumption with the alternative fuel and then calculating a petroleum equivalent fuel consumption using a Petroleum Equivalency Factor (PEF) that is determined by the Department of Energy. NHTSA proposed to treat electric vehicles as having zero fuel consumption, comparable to the EPA proposal. Both agencies proposed to determine FFV performance in the same way as for GHG emissions for light-duty vehicles, with a 50-50 weighting of alternative and conventional fuel test results through MY 2015, and a weighting based on demonstrated fuel use in the real world after MY 2015 (defaulting to an assumption of 100 percent conventional fuel use). This approach was considered to be a reasonable and logical way to properly credit alternative fuel use in FFVs in the real world without imposing a difficult burden of proof on manufacturers. However, unlike in the light-duty rule, the agencies do not believe it is appropriate to create a provision for additional incentives similar to the 2012-2015 light-duty incentive program (See 49 U.S.C. 32904) because the HD sector does not have the incentives mandated in EISA for light-duty FFVs, and so has not relied on the existence of such credits in devising compliance strategies for the early model years of this program. See 74 FR at 49531. In fact, manufacturers have not in the past produced FFV heavy-duty vehicles. On the other hand, the agencies sought comment on how to properly recognize the impact of the use of alternative fuels, and E85 in particular, in HD pickups and vans, including the proper accounting for alternative fuel use in FFVs in the real world. [36] See 75 FR at 74198.

The agencies received several comments from natural gas vehicle (NGV) interests arguing for greater crediting of NGVs than the proposed approach would have provided. Clean Energy, Hayday Farms, Border Valley, AGA, Ryder, Encana, and a group of NGV interests commented that the NPRM ignored Congress' intent to incentivize the use of NGVs by not including the conversion factor that exists in the light-duty statutory language. The commenters argued that Congress' intent to incentivize NGVs is evident in the formula contained in 49 U.S.C. 32905, which deems a gallon equivalent of gaseous fuel to have a fuel content of 0.15 gallon of fuel. The commenters also argued that Congress implicitly intended NGVs to be incentivized in this rulemaking, as evidenced by the incentives in the light-duty statutory text. AGA and Hayday suggested that the agencies were not including the NGV incentive from light-duty because Congress did not explicitly include it in 49 U.S.C. 32902(k), and argued that this would contradict the agencies' inclusion of other incentives similar to the light-duty rule.

The American Trucking Association expressed support for estimating natural gas fuel efficiency by using carbon emissions from natural gas rather than energy content to estimate fuel consumption. ATA explained that two vehicles can achieve the same fuel efficiency, yet one operated on natural gas would have a lower carbon dioxide emissions rate. A natural gas conversion factor that uses carbon content versus energy content is a more appropriate method for calculating fuel consumption, in the commenter's view. A number of other groups commented on the appropriate method to use in establishing fuel consumption from alternative fueled vehicles. A group of NGV interests, Ryder, Border Valley Trading, Waste Management, Robert Bosch and the Blue Green Alliance encouraged the agencies to adopt the 0.15 conversion factor in estimating fuel consumption for FFVs and alternative fuel vehicles finalized in the light-duty 2012-2016 MY vehicle standards. The suggested incentive would effectively reduce the calculated fuel consumption for FFVs and alternative fuel vehicles by a factor of 85 percent. The commenters argued that the incentive is needed for heavy-duty vehicles to encourage the use of natural gas and to reduce the nation's dependence on petroleum.

The agencies reassessed the options for evaluating the CO 2 and fuel consumption performance of alternative fuel vehicles in response to comments and because the agencies recognized that the treatment of alternate fuel vehicles was one of the few provisions in the proposal where the EPA and NHTSA programs were not aligned. The agencies conducted an analysis comparing fuel consumption calculated based on CO 2 emissions [37] to fuel consumption calculated based on gasoline or diesel energy equivalency to evaluate impacts of a consistent consumption measurement for all vehicle classes covered by this program and to further understand how alternative fuels would be impacted by this measurement methodology. In particular the agencies evaluated how measuring consumption via CO 2 emissions would hinder or benefit the application of alternative fuels versus following similar alternative fuel incentivizing programs provided via statute for the Agency's light-duty programs. The analysis showed measuring a vehicle's CO 2 output converted to fuel consumption provided a fuel consumption measurement benefit to those vehicles operating on fuels other than gasoline or diesel. For CNG, LNG and LPG the benefit is approximately 19 percent to 24 percent, for biodiesel and ethanol blends the benefit is approximately 1 percent to 3 percent, and for electricity and hydrogen fuels the benefit is 100 percent benefit, as fuel consumption is zero. The agencies also considered that the EPA Renewable Fuel Standard, [38] a separate program, requires an increase in the volume of renewable fuels used in the U.S. transportation sector. For the fuels covered by the Renewable Fuels Standard additional incentives are not needed in this regulation given the large volume increases required under the Renewable Fuel Standard.

The agencies continue to believe that alternative-fueled vehicles, including NGVs, provide fuel consumption benefits that should be, and are, accounted for in this program. However, the agencies do not agree with the commenters' claim that the NGV incentive contained in EISA, and reflected in the light-duty program, is an explicit Congressional directive that must also be applied to the heavy-duty program, nor that the light-duty incentive for NGVs should be interpreted as an implicit Congressional directive for NGVs to be comparably incentivized in the heavy-duty program. Further, the agencies believe that the fuel consumption benefits that alternative fuel vehicles would obtain through measuring CO 2 emissions for the EPA program and converting CO 2 emissions to fuel consumption for the NHTSA program accurately reflects their energy benefits. This accurate accounting, in conjunction with the volumetric increases required by the Renewable Fuels Standard, provides sufficient incentives for these vehicles. The agencies continue to believe that the light-duty conversion factor is not appropriate for this program. Instead, the agencies are finalizing measuring the performance of alternative fueled vehicles by measuring CO 2 emissions for the EPA program and converting CO 2 emissions to fuel consumption for the NHTSA program. The agencies are also finalizing measuring FFV performance with a 50-50 weighting of alternative and conventional fuel test results through MY 2015, and an agency- or manufacturer-determined weighting based on demonstrated fuel use in the real world after MY 2015 (defaulting to an assumption of 100 percent conventional fuel use).

The agencies believe this structure accurately reflects the fuel consumption of the vehicles while at the same time providing an incentive for the alternative fuel use. (For example, natural gas heavy duty engines perform 20 to 30 percent better than their diesel and gasoline counterparts from a CO 2 perspective, and so meet the standards adopted in these rules without cost, and indeed will be credit generators without cost.) We believe this is a substantial enough advantage to spur the market for these vehicles. The calculation at the same time does not overestimate the benefit from these technologies, which could reduce the effectiveness of the regulation. Therefore, the final rules do not include the light-duty 0.15 conversion factor for NGVs. The agencies would like to clarify that the decision not to include an NGV incentive was based on this policy determination, not on a belief that incentives present in the light-duty rule could not be developed for the heavy-duty sector because they were not explicitly included in Section 32902(k).

NHTSA recognizes that EPCA/EISA promotes incentives for alternative fueled vehicles for different purposes than does the CAA, and that there may be additional energy and national security benefits that could be achieved through increasing fleet percentages of natural gas and other alternative-fueled vehicles. More alternative-fueled vehicles on road would arguably displace petroleum-fueled vehicles, and thereby increase both U.S. energy and national security by reducing the nation's dependence on foreign oil.

However, a rule that adopts identical incentive provisions reduces industry reporting burdens and NHTSA's monitoring burden. In addition, the agencies are concerned that providing greater incentives under EPCA/EISA might lead to little increased production of alternative fueled vehicles. If this were the case, then the benefits of harmonization could outweigh any potential gains from providing greater incentives. It is also consistent with Executive Order 13563. [39]

Adopting the same incentive provisions could also have benefits for the public, the regulated industries, and the agencies. This approach allows manufacturers to project clear benefits for the application of GHG-reduction and fuel efficiency technologies, thus spurring their adoption.

This combined rulemaking by EPA and NHTSA is designed to regulate two separate characteristics of heavy duty vehicles: Greenhouse gas emissions (GHG) and fuel consumption. In the case of diesel or gasoline powered vehicles, there is a one-to-one relationship between these two characteristics. Each gallon of gasoline combusted by a truck engine generates approximately 8,887 grams of CO 2; and each gallon of diesel fuel burned generates about 10,180 grams of CO 2. Because no available technologies reduce tailpipe CO 2 emissions per gallon of fuel combusted, any rule that limits tailpipe CO 2 emissions is effectively identical to a rule that limits fuel consumption. Compliance by a truck manufacturer with the NHTSA fuel economy rule assures compliance with the EPA rule, and vice versa.

For alternatively fueled vehicles, which use no petroleum, the situation is different. For example, a natural gas vehicle that achieves approximately the same fuel economy as a diesel powered vehicle would emit 20 percent less CO 2; and a natural gas vehicle with the same fuel economy as a gasoline vehicle would emit 30 percent less CO 2. Yet natural gas vehicles consume no petroleum. To the extent that the goal of the NHTSA fuel economy portion of this rulemaking is to curb petroleum use, crediting natural gas vehicles with zero fuel consumption per mile could contribute to achieving that goal. Similar differences between oil consumption and greenhouse gas emissions would apply to electric vehicles, hybrid electric vehicles, and biofuel-powered vehicles.

NHTSA notes that the purpose of EPCA/EISA is not merely to curb petroleum use—it is more generally to secure energy independence, which can be achieved by reducing petroleum use. The value of incentivizing natural gas, electric vehicles, biofuels, hydrogen, or other alt fuel vehicles for energy independence is limited to the extent that the alternative fuels may be imported.

In the recent rulemaking for light-duty vehicles, EPA and NHTSA have followed the light duty specific statutory provision that treats one gallon of alternative fuel as equivalent to 0.15 gallons of gasoline until MY 2016, when performance on the EPA CO 2 standards is measured based on actual emissions. 75 FR at 25433. Following that MY 2012-2015 approach in this heavy duty program would mean that, for example, a natural gas powered truck would have attributed to it 20 percent less CO 2 emissions than a comparable diesel powered truck, but 85 percent less fuel consumption. Engine manufacturers with a relatively large share of alternative-fuel products would likely have an easier time complying with NHTSA's average fuel economy standard than with EPA's GHG standard. Similarly, engine manufacturers with a relatively small share of alternative-fuel products would have a relatively easier time complying with EPA's CO 2 standard than with NHTSA's fuel economy standard. In that way, the rule would not differ from the light duty vehicle rules.

Instead, in this program, EPA and NHTSA are establishing identical rules. Fuel consumption for alternatively-powered vehicles will be calculated according to their tailpipe CO 2 emissions. In that way, there will be a one-to-one relationship between fuel economy and tailpipe CO 2 emissions for all vehicles. However, this might not result in a one-to-one relationship between petroleum consumption and GHG emissions for all vehicles. On the other hand, it could have the disadvantage of not doing more to encourage some cost-effective means of reducing petroleum consumption by trucks, and the accompanying energy security costs. By attributing to natural gas engines only 20 percent less fuel consumption than comparable diesel engines, because they emit 20 percent less CO 2, rather than attributing to them a much larger percentage reduction in fuel consumption, because they use no petroleum, this uniform approach to rulemaking provides less of an incentive for technologies that reduce consumption of petroleum-based fuels.

In the future, the Agencies will consider the possibility of proposing standards in a way that more fully reflects differences in fuel consumption and greenhouse gas emissions. Under such standards, any given vehicle might “over-comply” with the fuel economy standard, but might “under-comply” with the greenhouse gas standard. Therefore, in meeting the fleet-wide requirements, a manufacturer would need to meet both standards using all available options, such as credit trading and technology mix. Allowing for two distinct standards might enable manufacturers to achieve the twin goals of reducing greenhouse gas emissions and decreasing consumption of petroleum-based fuels in a more cost-effective manner.

D. Summary of Costs and Benefits of the HD National Program

This section summarizes the projected costs and benefits of the final NHTSA fuel consumption and EPA GHG emissions standards. These projections helped to inform the agencies' choices among the alternatives considered and provide further confirmation that the final standards are an appropriate choice within the spectrum of choices allowable under the agencies' respective statutory criteria. NHTSA and EPA have used common projected costs and benefits as the bases for our respective standards.

The agencies have analyzed in detail the projected costs, fuel savings, and benefits of the final GHG and fuel consumption standards. Table I-5 shows estimated lifetime discounted program costs (including technological outlays), fuel savings, and benefits for all heavy-duty vehicles projected to be sold in model years 2014-2018 over these vehicles' lives. The benefits include impacts such as climate-related economic benefits from reducing emissions of CO 2 (but not other GHGs) and reductions in energy security externalities caused by U.S. petroleum consumption and imports. The analysis also includes economic impacts stemming from additional heavy-duty vehicle use attributable to fuel savings, such as the economic damages caused by accidents, congestion and noise. Note that benefits reflect on estimated values for the social cost of carbon (SCC), as described in Section VIII.G.

The costs, fuel savings, and benefits summarized here are slightly higher than at proposal, reflecting the use of 2009 (versus 2008) dollars, some minor changes to our cost estimates in response to comments, and a change to the 2011 Annual Energy Outlook (AEO) estimate of economic growth and future fuel prices. In aggregate, these changes lead to an increased estimate of the net benefits of the final action compared to the proposal.

Table I-5—Estimated Lifetime Discounted Costs, Fuel Savings, Benefits, and Net Benefits for 2014-2018 Model Year Heavy-Duty Vehicles a b Back to Top
[Billions, 2009$]
Notes:
a The agencies estimated the benefits associated with four different values of a one ton CO 2 reduction (model average at 2.5% discount rate, 3%, and 5%; 95th percentile at 3%), which each increase over time. For the purposes of this overview presentation of estimated costs and benefits, however, we are showing the benefits associated with the marginal value deemed to be central by the interagency working group on this topic: the model average at 3% discount rate, in 2009 dollars. Section VIII.F provides a complete list of values for the 4 estimates.
b Note that net present value of reduced GHG emissions is calculated differently than other benefits. The same discount rate used to discount the value of damages from future emissions (SCC at 5, 3, and 2.5 percent) is used to calculate net present value of SCC for internal consistency. Refer to Section VIII.F for more detail.
c Present value is the total, aggregated amount that a series of monetized costs or benefits that occur over time is worth now (in year 2009 dollar terms), discounting future values to the present.
d Net benefits reflect the fuel savings plus benefits minus costs.
e The annualized value is the constant annual value through a given time period (2012 through 2050 in this analysis) whose summed present value equals the present value from which it was derived.
Lifetime Present Valuec—3% Discount Rate  
Program Costs $8.1
Fuel Savings $50
Benefits $7.3
Net Benefitsd $49
Annualized Valuee—3% Discount Rate  
Annualized Costs $0.4
Fuel Savings $2.2
Annualized Benefits $0.4
Net Benefitsd $2.2
Lifetime Present Valuec—7% Discount Rate  
Program Costs $8.1
Fuel Savings $34
Benefits $6.7
Net Benefitsd $33
Annualized Valuee—7% Discount Rate  
Annualized Costs $0.6
Fuel Savings $2.6
Annualized Benefits $0.5
Net Benefitsd $2.5

Table I-6 shows the estimated lifetime reductions in CO 2 emissions (in million metric tons (MMT)) and fuel consumption for all heavy-duty vehicles sold in the model years 2014-2018. The values in Table I-6 are projected lifetime totals for each model year and are not discounted. The two agencies' standards together comprise the HD National Program, and the agencies' respective GHG emissions and fuel consumption standards, jointly, are the source of the benefits and costs of the HD National Program.

Table I-6—Estimated Lifetime Reductions in Fuel Consumption and CO 2 Emissions for 2014-2018 Model Year HD Vehicles Back to Top
All heavy-duty vehicles 2014 MY 2015 MY 2016 MY 2017 MY 2018 MY Total
Note:
a Includes upstream and downstream CO 2 reductions.
Fuel (billion gallons) 4.0 3.6 3.6 5.1 5.8 22.1
Fuel (billion barrels) 0.10 0.09 0.08 0.12 0.14 0.53
CO 2 (MMT) a 50.2 44.8 44.0 62.8 71.7 273

Table I-7 shows the estimated lifetime discounted benefits for all heavy-duty vehicles sold in model years 2014-2018. Although the agencies estimated the benefits associated with four different values of a one ton CO 2 reduction ($5, $22, $36, $66), for the purposes of this overview presentation of estimated benefits the agencies are showing the benefits associated with one of these marginal values, $22 per ton of CO 2, in 2009 dollars and 2010 emissions. Table I-7 presents benefits based on the $22 per ton of CO 2 value. Section VIII.F presents the four marginal values used to estimate monetized benefits of CO 2 reductions and Section VIII presents the program benefits using each of the four marginal values, which represent only a partial accounting of total benefits due to omitted climate change impacts and other factors that are not readily monetized. The values in the table are discounted values for each model year of vehicles throughout their projected lifetimes. The analysis includes other economic impacts such as energy security, and other externalities such as impacts on accidents, congestion and noise. However, the model year lifetime analysis supporting the program omits other impacts such as benefits related to non-GHG emission reductions. [40] The lifetime discounted benefits are shown for one of four different SCC values considered by EPA and NHTSA. The values in Table I-7 do not include costs associated with new technology required to meet the GHG and fuel consumption standards.

Table I-7—Estimated Lifetime Discounted Benefits for 2014-2018 Model Year HD Vehicles Assuming the Model Average, 3% Discount Rate SCC Value a b c Back to Top
Discount rate (percent) Model year
2014 2015 2016 2017 2018 Total
[billions of 2009 dollars]
Notes:
a The analysis includes impacts such as the economic value of reduced fuel consumption and accompanying climate-related economic benefits from reducing emissions of CO 2 (but not other GHGs), and reductions in energy security externalities caused by U.S. petroleum consumption and imports. The analysis also includes economic impacts stemming from additional heavy-duty vehicle use, such as the economic damages caused by accidents, congestion and noise.
b Note that net present value of reduced CO 2 emissions is calculated differently than other benefits. The same discount rate used to discount the value of damages from future emissions (SCC at 5, 3, and 2.5 percent) is used to calculate net present value of SCC for internal consistency. Refer to Section VIII.F for more detail, including a list of all four SCC values, which increase over time.
c Benefits in this table include fuel savings.
3 $10.7 $9.4 $9.2 $13.2 $14.9 $57
7 8.3 6.9 6.6 9.2 10.1 41

Table I-8 shows the agencies' estimated lifetime fuel savings, lifetime CO 2 emission reductions, and the monetized net present values of those fuel savings and CO 2 emission reductions. The gallons of fuel and CO 2 emission reductions are projected lifetime values for all vehicles sold in the model years 2014-2018. The estimated fuel savings in billions of barrels and the GHG reductions in million metric tons of CO 2 shown in Table I-8 are totals for the five model years throughout their projected lifetime and are not discounted. The monetized values shown in Table I-8 are the summed values of the discounted monetized-fuel consumption and monetized-CO 2 reductions for the five model years 2014-2018 throughout their lifetimes. The monetized values in Table I-8 reflect both a 3 percent and a 7 percent discount rate as noted.

Table I-8—Estimated Lifetime Reductions and Associated Discounted Monetized Benefits for 2014-2018 Model Year HD Vehicles Back to Top
Amount $ Value (billions)
[Monetized values in 2009 dollars]
Notes:
aIncludes both upstream and downstream CO 2 emission reductions.
bNote that net present value of reduced CO 2 emissions is calculated differently than other benefits. The same discount rate used to discount the value of damages from future emissions (SCC at 5, 3, and 2.5 percent) is used to calculate net present value of SCC for internal consistency. Refer to Section VIII.F for more detail.
Fuel Consumption Reductions 0.53 billion barrels $50.1, 3% discount rate $34.4, 7% discount rate.
CO 2 Emission ReductionsaValued assuming $22/ton CO 2 in 2010 273 MMT CO 2 $5.8b.

Table I-9 shows the estimated incremental and total technology outlays for all heavy-duty vehicles for each of the model years 2014-2018. The technology outlays shown in Table I-9 are for the industry as a whole and do not account for fuel savings associated with the program.

Table I-9—Estimated Incremental Technology Outlays for 2014-2018 Model Year HD Vehicles Back to Top
2014 MY 2015 MY 2016 MY 2017 MY 2018 MY Total
[Billions of 2009 dollars]
All Heavy-Duty Vehicles $1.6 $1.4 $1.5 $1.6 $2.0 $8.1

Table I-10 shows the agencies' estimated incremental cost increase of the average new heavy-duty vehicle for each model year 2014-2018. The values shown are incremental to a baseline vehicle and are not cumulative.

Table I-10—Estimated Incremental Increase in Average Cost for 2014-2018 Model Year HD Vehicles Back to Top
2014 MY 2015 MY 2016 MY 2017 MY 2018 MY
[2009 Dollars per unit]
Combination Tractors $6,019 $5,871 $5,677 $6,413 $6,215
HD Pickups & Vans 165 215 422 631 1,048
Vocational Vehicles 329 320 397 387 378

Both costs and benefits presented in this section are in comparison to a reference case with no improvements in fuel consumption or greenhouse gas emissions in model years 2014 to 2018.

E. Program Flexibilities

For each of the heavy-duty vehicle and heavy-duty engine categories for which we are adopting respective standards, EPA and NHTSA are also finalizing provisions designed to give manufacturers a degree of flexibility in complying with the standards. These final provisions have enabled the agencies to consider overall standards that are more stringent and that will become effective sooner than we could consider with a more rigid program, one in which all of a manufacturer's similar vehicles or engines would be required to achieve the same emissions or fuel consumption levels, and at the same time. [41] We believe that incorporating carefully structured regulatory flexibility provisions into the overall program is an important way to achieve each agency's goals for the program.

NHTSA's and EPA's flexibility provisions are essentially identical in structure and function. Within combination tractor and vocational vehicle categories and within heavy-duty engines, we are finalizing four primary types of flexibility: Averaging, banking, and trading (ABT) provisions; early credits; advanced technology credits (including hybrid powertrains); and innovative technology credit provisions. The final ABT provisions are patterned on existing EPA and NHTSA ABT programs and will allow a vehicle manufacturer to reduce CO 2 emission and fuel consumption levels further than the level of the standard for one or more vehicles to generate ABT credits. The manufacturer can use those credits to offset higher emission or fuel consumption levels in the same averaging set, “bank” the credits for later use, or “trade” the credits to another manufacturer. For HD pickups and vans, we are finalizing a fleet averaging system very similar to the light-duty GHG and CAFE fleet averaging system.

At proposal, we restricted the use of the ABT provisions of the program to vehicles or engines within the same regulatory subcategory. This meant that credit exchanges could only happen between similar vehicles meeting the same standards. We proposed this approach for two reasons. First, we were concerned about a level playing field between different manufacturers who may not participate equally in the various truck and engine markets covered in the regulation. Second, we were concerned about the uncertainties inherent in credit calculations that are based on projections of lifetime emissions for different vehicles in wholly different vehicle markets. In response to comments, we have revised our ABT provisions to provide greater flexibility while continuing to provide assurance that the projected reductions in fuel consumption and GHG emissions will be achieved. We are relaxing the restriction on averaging, banking, and trading of credits between the various regulatory subcategories, by defining three HD vehicle averaging sets: Light Heavy-Duty (Classes 2b-5); Medium Heavy-Duty (Class 6-7); and Heavy Heavy-Duty (Class 8). This allows the use of credits between vehicles within the same weight class. This means that a Class 8 day cab tractor can exchange credits with a Class 8 high roof sleeper tractor but not with a smaller Class 7 tractor. Also, a Class 8 vocational vehicle can exchange credits with a Class 8 tractor. We are adopting these revisions based on comments from the regulated industry that convinced us these changes would allow the broadest trading possible while maintaining a level playing field among the various market segments. However, we are restricting trading between engines and chassis, even within the same vehicle class.

The agencies believe that restricting trading to within the same eight classes as EPA's existing criteria pollutant program (i.e. Heavy-Heavy Duty, Light Heavy-Duty, Medium Heavy-Duty), but not restricting trading between vehicle or engine type (such as combination tractors), and restricting between engines and chassis for the same vehicle type, is appropriate and reasonable. We do not expect emissions from engines and vehicles—when restricted by weight class—to be dissimilar. We therefore expect that the lifetime vehicle performance and emissions levels will be very similar across these defined categories, and the estimated credit calculations will fairly ensure the expected fuel consumption and GHG reductions.

The agencies considered even broader averaging, banking, and trading provisions but decided that in this first phase of regulation, it would be prudent to start with the program described here, which will regulate greenhouse gas emissions and fuel consumption from this sector for the first time and provide considerable early reductions as well as opportunities to learn about technical and other issues that can inform future rulemakings. In the future we intend to consider whether additional cost savings could be realized through broader trading provisions and whether such provisions could be designed so as to address any other relevant concerns.

Reducing the cost of regulation through broader use of market tools is a high priority for the Administration. See Executive Order 13563 and in particular section 1(b)(5) and section 4. Consistent with this principle, we intend to seek public comment through a Notice of Data Availability after credit trading begins in 2013, the first year we expect manufacturers to begin certifying 2014 model year vehicles, on whether broader credit trading is more appropriate in developing the next phase of heavy-duty regulations. We believe that input will be better informed by the work the agencies and the regulated industry will have put into implementing this first phase of heavy-duty regulations.

Through this public process, emphasizing the Administration's strong preference for flexible approaches and maximizing the use of market tools, the agencies intend to fully consider whether broader credit trading is more appropriate in developing the next phase of heavy-duty regulations.

This program thus does not allow credits to be exchanged between heavy-duty vehicles and light-duty vehicles, nor can credits be traded from heavy-duty vehicle fleets to light-duty vehicle fleets and vice versa.

The engine ABT provisions are also changed from the proposal and now are the same as in EPA's existing criteria pollutant emission rules. The agencies have broadened the averaging sets to include both FTP-certified and SET-certified engines in the same averaging set. For example, a SET-certified engine intended for a Class 8 tractor can exchange credits with a FTP-certified engine intended for a Class 8 vocational vehicle.

The agencies are finalizing three year deficit carry-forward provisions for heavy-duty engines and vehicles within a limited time frame. This flexibility is expected to provide an opportunity for manufacturers to make necessary technological improvements and reduce the overall cost of the program without compromising overall environmental and fuel economy objectives. This flexibility, similar to the flexibility the agencies have offered under the light-duty vehicle program, is intended to assist the broad goal of harmonizing the two agencies' standards while preserving the flexibility of manufacturers of vehicles and engines in meeting the standards, to the extent appropriate and required by law. During the MYs 2014-2018 manufacturers are expected to go through the normal business cycle of redesigning and upgrading their heavy-duty engine and vehicle products, and in some cases introducing entirely new vehicles and engines not on the market today. As explained in the following paragraph, the carry-forward provision will allow manufacturers the time needed to incorporate technology to achieve GHG reductions and improve fuel economy during the vehicle redesign process.

We received comments from Center for Biological Diversity against the need to offer the deficit carry-forward flexibility. CBD has stated that allowing manufacturers to carry-forward deficits for up to three years would incentivize delays in investment and technological innovation and allow for the generation of additional tons of GHG emissions that may be prevented today. However, the deficit carry-forward flexibility (as well as ABT generally) has enabled the agencies to consider overall standards that are more stringent and that will become effective at an earlier period than we could consider with a more rigid program. The agencies also believe this flexibility is an important aspect of the program, as it avoids the much higher costs that would occur if manufacturers needed to add or change technology at times other than their scheduled redesigns, i.e. the cost of adopting a new engine or vehicle platform mid-production or mid-design. This time period would also provide manufacturers the opportunity to plan for compliance using a multi-year time frame, again consistent with normal business practice. Over these four model years, there would be an opportunity for manufacturers to evaluate practically all of their vehicle and engine model platforms and add technology in a cost effective way to control GHG emissions and improve fuel economy.

As noted above, in addition to ABT, the other primary flexibility provisions in this program involve opportunities to generate early credits, advanced technology credits (including for use of hybrid powertrains), and innovative technology credits. For the early credits and advanced technology credits, the agencies sought comment on the appropriateness of providing a 1.5x multiplier as an incentive for their use. We received a number of comments supporting the idea of a credit multiplier, arguing it was an appropriate means to incentivize the early compliance and advanced technologies the agencies sought. We received other comments suggesting a multiplier was unnecessary. After considering the comments, the agencies have decided to finalize a 1.5x multiplier consistent with our request for comments. We believe that given the very short lead time of the program and the nascent nature of the advanced technologies identified in the proposal, that a 1.5x multiplier is an effective means to bring technology forward into the heavy-duty sector sooner than would otherwise occur. In addition, advanced technology credits could be used anywhere within the heavy duty sector (including both vehicles and engines), but early credits would be restricted to use within the same defined averaging set generating the credit.

For other technologies which can reduce CO 2 and fuel consumption, but for which there do not yet exist established methods for quantifying reductions, the agencies still wish to encourage the development of such innovative technologies, and are therefore adopting special “innovative technology” credits. These innovative technology credits will apply to technologies that are shown to produce emission and fuel consumption reductions that are not adequately recognized on the current test procedures and that are not yet in widespread use in the heavy-duty sector. Manufacturers will need to quantify the reductions in fuel consumption and CO 2 emissions that the technology is expected to achieve, above and beyond those achieved on the existing test procedures. As with ABT, the use of innovative technology credits will only be allowed for use among vehicles and engines of the same defined averaging set generating the credit, as described above. The credit multiplier will not be used for innovative technology credits.

CBD argued that including any opportunities for manufacturers to earn credits in the final rule would violate NHTSA's statutory mandate to implement a program designed to achieve the maximum feasible improvement.

NHTSA strongly believes that creating credit flexibilities for manufacturers for this first phase of the HD National Program is fully consistent with the agency's obligation to develop a fuel efficiency improvement program designed to achieve the maximum feasible improvement. EISA gives NHTSA broad authority to develop “compliance and enforcement protocols” that are “appropriate, cost-effective, and technologically feasible,” and the agency believes that compliance flexibilities such as the opportunity to earn and use credits to meet the standards are a reasonable and appropriate interpretation of that authority, along with the other compliance and enforcement provisions developed for this final rule. Unlike in NHTSA's light-duty program, where the agency is restricted from considering the availability of credits in determining the maximum feasible level of stringency for the fuel economy standards, [42] in this HD National Program, NHTSA and EPA have based the levels of stringency in part on our assumptions of the use of available flexibilities that have been built into the program to incentivize over-compliance in some respects, to balance out potential under-compliance in others.

By assuming the use of credits for compliance, the agencies were able to set the fuel consumption/GHG standards at more stringent levels than would otherwise have been feasible. Greater improvements in fuel efficiency will occur under more stringent standards; manufacturers will simply have greater flexibility to determine where and how to make those improvements than they would have without credit options. Further, this is consistent with EOs 12866 and 13563, which encourage agencies to design regulations that promote innovation and flexibility where possible. [43]

A detailed discussion of each agency's ABT, early credit, advanced technology, and innovative technology provisions for each regulatory category of heavy-duty vehicles and engines is found in Section IV below.

F. EPA and NHTSA Statutory Authorities

(1) EPA Authority

Title II of the CAA provides for comprehensive regulation of mobile sources, authorizing EPA to regulate emissions of air pollutants from all mobile source categories. When acting under Title II of the CAA, EPA considers such issues as technology effectiveness, its cost (both per vehicle, per manufacturer, and per consumer), the lead time necessary to implement the technology, and based on this the feasibility and practicability of potential standards; the impacts of potential standards on emissions reductions of both GHGs and non-GHGs; the impacts of standards on oil conservation and energy security; the impacts of standards on fuel savings by customers; the impacts of standards on the truck industry; other energy impacts; as well as other relevant factors such as impacts on safety.

This final action implements a specific provision from Title II, section 202(a). [44] Section 202(a)(1) of the CAA states that “the Administrator shall by regulation prescribe (and from time to time revise) * * * standards applicable to the emission of any air pollutant from any class or classes of new motor vehicles * * *, which in his judgment cause, or contribute to, air pollution which may reasonably be anticipated to endanger public health or welfare.” With EPA's December 2009 final findings that certain greenhouse gases may reasonably be anticipated to endanger public health and welfare and that emissions of GHGs from section 202 (a) sources cause or contribute to that endangerment, section 202(a) requires EPA to issue standards applicable to emissions of those pollutants from new motor vehicles.

Any standards under CAA section 202(a)(1) “shall be applicable to such vehicles * * * for their useful life.” Emission standards set by the EPA under CAA section 202(a)(1) are technology-based, as the levels chosen must be premised on a finding of technological feasibility. Thus, standards promulgated under CAA section 202(a) are to take effect only “after providing such period as the Administrator finds necessary to permit the development and application of the requisite technology, giving appropriate consideration to the cost of compliance within such period” (section 202(a)(2); see also NRDC v. EPA, 655 F. 2d 318, 322 (DC Cir. 1981)). EPA is afforded considerable discretion under section 202(a) when assessing issues of technical feasibility and availability of lead time to implement new technology. Such determinations are “subject to the restraints of reasonableness”, which “does not open the door to `crystal ball' inquiry.”NRDC, 655 F. 2d at 328, quoting International Harvester Co. v. Ruckelshaus, 478 F. 2d 615, 629 (DC Cir. 1973). However, “EPA is not obliged to provide detailed solutions to every engineering problem posed in the perfection of the trap-oxidizer. In the absence of theoretical objections to the technology, the agency need only identify the major steps necessary for development of the device, and give plausible reasons for its belief that the industry will be able to solve those problems in the time remaining. The EPA is not required to rebut all speculation that unspecified factors may hinder `real world' emission control.”NRDC, 655 F. 2d at 333-34. In developing such technology-based standards, EPA has the discretion to consider different standards for appropriate groupings of vehicles (“class or classes of new motor vehicles”), or a single standard for a larger grouping of motor vehicles (NRDC, 655 F. 2d at 338).

Although standards under CAA section 202(a)(1) are technology-based, they are not based exclusively on technological capability. EPA has the discretion to consider and weigh various factors along with technological feasibility, such as the cost of compliance (See section 202(a) (2)), lead time necessary for compliance (section 202(a)(2)), safety (See NRDC, 655 F. 2d at 336 n. 31) and other impacts on consumers, and energy impacts associated with use of the technology. See George E. Warren Corp. v. EPA, 159 F.3d 616, 623-624 (DC Cir. 1998) (ordinarily permissible for EPA to consider factors not specifically enumerated in the CAA). See also Entergy Corp. v. Riverkeeper, Inc., 129 S.Ct. 1498, 1508-09 (2009) (congressional silence did not bar EPA from employing cost-benefit analysis under Clean Water Act absent some other clear indication that such analysis was prohibited; rather, silence indicated discretion to use or not use such an approach as the agency deems appropriate).

In addition, EPA has clear authority to set standards under CAA section 202(a) that are technology forcing when EPA considers that to be appropriate, but is not required to do so (as compared to standards set under provisions such as section 202(a)(3) and section 213(a)(3)). [45] EPA has interpreted a similar statutory provision, CAA section 231, as follows:

While the statutory language of section 231 is not identical to other provisions in title II of the CAA that direct EPA to establish technology-based standards for various types of engines, EPA interprets its authority under section 231 to be somewhat similar to those provisions that require us to identify a reasonable balance of specified emissions reduction, cost, safety, noise, and other factors. See, e.g., Husqvarna AB v. EPA, 254 F.3d 195 (DC Cir. 2001) (upholding EPA's promulgation of technology-based standards for small non-road engines under section 213(a)(3) of the CAA). However, EPA is not compelled under section 231 to obtain the “greatest degree of emission reduction achievable” as per sections 213 and 202 of the CAA, and so EPA does not interpret the Act as requiring the agency to give subordinate status to factors such as cost, safety, and noise in determining what standards are reasonable for aircraft engines. Rather, EPA has greater flexibility under section 231 in determining what standard is most reasonable for aircraft engines, and is not required to achieve a “technology forcing” result (70 FR 69664 and 69676, November 17, 2005).

This interpretation was upheld as reasonable in NACAA v. EPA, 489 F.3d 1221, 1230 (DC Cir. 2007). CAA section 202(a) does not specify the degree of weight to apply to each factor, and EPA accordingly has discretion in choosing an appropriate balance among factors. See Sierra Club v. EPA, 325 F.3d 374, 378 (DC Cir. 2003) (even where a provision is technology-forcing, the provision “does not resolve how the Administrator should weigh all [the statutory] factors in the process of finding the `greatest emission reduction achievable' ”). See also Husqvarna AB v. EPA, 254 F. 3d 195, 200 (DC Cir. 2001) (great discretion to balance statutory factors in considering level of technology-based standard, and statutory requirement “to [give appropriate] consideration to the cost of applying * * * technology” does not mandate a specific method of cost analysis); see also Hercules Inc. v. EPA, 598 F. 2d 91, 106 (DC Cir. 1978) (“In reviewing a numerical standard the agencies must ask whether the agency's numbers are within a zone of reasonableness, not whether its numbers are precisely right”); Permian Basin Area Rate Cases, 390 U.S. 747, 797 (1968) (same); Federal Power Commission v. Conway Corp., 426 U.S. 271, 278 (1976) (same); Exxon Mobil Gas Marketing Co. v. FERC, 297 F. 3d 1071, 1084 (DC Cir. 2002) (same).

(a) EPA Testing Authority

Under section 203 of the CAA, sales of vehicles are prohibited unless the vehicle is covered by a certificate of conformity. EPA issues certificates of conformity pursuant to section 206 of the Act, based on (necessarily) pre-sale testing conducted either by EPA or by the manufacturer. The Heavy-duty Federal Test Procedure (Heavy-duty FTP) and the Supplemental Engine Test (SET) are used for this purpose. Compliance with standards is required not only at certification but throughout a vehicle's useful life, so that testing requirements may continue post-certification. Useful life standards may apply an adjustment factor to account for vehicle emission control deterioration or variability in use (section 206(a)).

EPA established the Light-duty FTP for emissions measurement in the early 1970s. In 1976, in response to the Energy Policy and Conservation Act, EPA extended the use of the Light-duty FTP to fuel economy measurement (See 49 U.S.C. 32904(c)). EPA can determine fuel efficiency of a vehicle by measuring the amount of CO 2 and all other carbon compounds (e.g., total hydrocarbons and carbon monoxide (CO)), and then, by mass balance, calculating the amount of fuel consumed.

(b) EPA Enforcement Authority

Section 207 of the CAA grants EPA broad authority to require manufacturers to remedy vehicles if EPA determines there are a substantial number of noncomplying vehicles. In addition, section 205 of the CAA authorizes EPA to assess penalties of up to $37,500 per vehicle for violations of various prohibited acts specified in the CAA. In determining the appropriate penalty, EPA must consider a variety of factors such as the gravity of the violation, the economic impact of the violation, the violator's history of compliance, and “such other matters as justice may require.”

(2) NHTSA Authority

In 1975, Congress enacted the Energy Policy and Conservation Act (EPCA), mandating a regulatory program for motor vehicle fuel economy to meet the various facets of the need to conserve energy. In December 2007, Congress enacted the Energy Independence and Securities Act (EISA), amending EPCA to require, among other things, the creation of a medium- and heavy-duty fuel efficiency program for the first time. This mandate in EISA represents a major step forward in promoting EPCA's goals of energy independence and security, and environmental and national security.

NHTSA has primary responsibility for fuel economy and consumption standards, and assures compliance with EISA through rulemaking, including standard-setting; technical reviews, audits and studies; investigations; and enforcement of implementing regulations including penalty actions. This final action implements Section 32902(k)(2) of EISA, which instructs NHTSA to create a fuel efficiency improvement program for “commercial medium- and heavy-duty on-highway vehicles and work trucks” [46] by rulemaking, which is to include standards, test methods, measurement metrics, and enforcement protocols. See 49 U.S.C. 32902(k)(2). Congress directed that the standards, test methods, measurement metrics, and compliance and enforcement protocols be “appropriate, cost-effective, and technologically feasible” for the vehicles to be regulated, while achieving the “maximum feasible improvement” in fuel efficiency.

NHTSA has clear authority to design and implement a fuel efficiency program for vehicles and work trucks under EISA, and was given broad discretion to balance the statutory factors in Section 32902(k)(2) in developing fuel consumption standards to achieve the maximum feasible improvement. Since this is the first rulemaking that NHTSA has conducted under 49 U.S.C. 32902(k)(2), the agency interpreted these elements and factors in the context of setting standards, choosing metrics, and determining test methods and compliance/enforcement mechanisms. Discussion of the application of these factors can be found in Section III below. Congress also gave NHTSA the authority to set separate standards for different classes of these vehicles, but required that all standards adopted provide not less than four full model years of regulatory lead-time and three full model years of regulatory stability.

In EISA, Congress required NHTSA to prescribe separate average fuel economy standards for passenger cars and light trucks in accordance with the provisions in 49 U.S.C. Section 32902(b), and to prescribe standards for work trucks and commercial medium- and heavy-duty vehicles in accordance with the provisions in 49 U.S.C. 32902(k). See 49 U.S.C. Section 32902(b)(1). Congress also added in EISA a requirement that NHTSA shall issue regulations prescribing fuel economy standards for at least 1, but not more than 5, model years. See 49 U.S.C. 32902(b)(3)(B). For purposes of the fuel efficiency standards that the agency proposed for HD vehicles and engines, the NPRM stated an interpretation of the statute that the 5-year maximum limit did not apply to standards promulgated in accordance with 49 U.S.C. 32902(k), given the language in Section 32902(b)(1). Based on this interpretation, NHTSA proposed that the standards ultimately finalized for HD vehicles and engines would remain in effect indefinitely at their 2018 or 2019 model year levels until amended by a future rulemaking action. In any future rulemaking action to amend the standards, NHTSA would ensure not less than four full model years of regulatory lead-time and three full model years of regulatory stability. NHTSA sought comment on its interpretation of EISA.

Robert Bosch LLC (Bosch) commented that the absence of an expiration date for the standards proposed in the NPRM could violate 49 U.S.C. 32902, which it interpreted as requiring the MD/HD program to have standards that expire in five years. Section 32902(k)(3), which lays out the requirements for the MD/HD program, specifies the minimum regulatory lead and stability times, as described above, but does not specify a maximum duration period. In contrast, Section 32902(b)(3)(B) lays out the minimum and maximum durations of standards to be established in a rulemaking for the light-duty program, but prescribes no minimum lead or stability time. Bosch argued that as 49 U.S.C. Section 32902(k)(3) does not require a maximum duration period, Congress intended that NHTSA take the maximum duration period specified for the light-duty program in Section 32902(b)(3)(B), five years, and apply it to Section 32902(k)(3). Bosch also argued, however, that the minimum duration period should not be carried over from the light-duty to the heavy-duty section, as a minimum duration period for HD was specified in Section 32902(k)(3).

NHTSA has revisited this issue and continues to believe that it is reasonable to assume that if Congress intended for the HD/MD regulatory program to be limited by the timeline prescribed in Subsection (b)(3)(B), it would have either mentioned HD/MD vehicles in that subsection or included the same timeline in Subsection (k). [47] In addition, in order for Subsection (b)(3)(B) to be interpreted to apply to Subsection (k), the agency would need to give less than full weight to the earlier phrase in the statute directing the Secretary to prescribe standards for “work trucks and commercial medium-duty or heavy-duty on-highway vehicles in accordance with Subsection (k).” 49 U.S.C. 32902(b)(1)(C). Instead, this direction would need to be read to mean “in accordance with Subsection (k) and the remainder of Subsection (b).” NHTSA believes this interpretation would be inappropriate. Interpreting “in accordance with Subsection (k)” to mean something indistinct from “in accordance with this Subsection” goes against the canon that statutes should not be interpreted in a way that “render[s] language superfluous.”Dobrova v. Holder, 607 F.3d 297, 302 (2d Cir. 2010), quoting Mendez v. Holder, 566 F. 3d 316, 321-22 (2d Cir. 2009). Based on this reasoning, NHTSA believes the more reasonable and appropriate approach is reflected in the proposal, and the final rules therefore follow this approach.

Another commenter, CBD, expressed concern that lack of an expiration date meant that the standards would remain indefinitely, thus forgoing the possibility of increased stringency in the future. CBD argued that this violated NHTSA's statutory duty to set maximum feasible standards. NHTSA disagrees that the indefinite duration of the standards in this rule would prevent the agency from setting future standards at the maximum feasible level in future rulemakings. The absence of an expiration date for these standards should not be interpreted to mean that there will be no future rulemakings to establish new MD/HD fuel efficiency standards for MYs 2019 and beyond—the agencies have already previewed the possibility of such a rulemaking in other parts of this final rule preamble. Therefore, NHTSA believes this concern is unnecessary.

(a) NHTSA Testing Authority

49 U.S.C. Section 32902(k)(2) states that NHTSA must adopt and implement appropriate, cost-effective, and technologically feasible test methods and measurement metrics as part of the fuel efficiency improvement program. For this program, manufacturers will test and conduct modeling to determine GHG emissions and fuel consumption performance, and EPA and NHTSA will perform validation testing. The results of the validation tests will be used by EPA to create a finalized reporting that confirms the manufacturer's final model year GHG emissions and fuel consumption results, which each agency will use to enforce compliance with its standards.

(v) NHTSA Enforcement Authority

(i) Overview

The NPRM proposed a compliance and enforcement program that included civil penalties for violations of the fuel efficiency standards. 49 U.S.C. 32902(k)(2) states that NHTSA must adopt and implement appropriate, cost-effective, and technologically feasible compliance and enforcement protocols for the fuel efficiency improvement program. Congress gave DOT broad discretion to fashion its fuel efficiency improvement program and thus necessarily did not speak directly or specifically as to the nature of the compliance and enforcement protocols that would be best suited for effectively supporting the yet-to-be-designed-and-established program. Instead, it left the matter generally to the Secretary. Congress' approach is unlike CAFE enforcement for passenger cars and light trucks, where Congress specified the precise details of a program and provided that a manufacturer either complies with standards or pays civil penalties.

The statute is silent with respect to how “protocol” should be interpreted. The term “protocol” is imprecise and thus Congress' choice of that term affords the agency substantial breadth of discretion. For example, in a case interpreting Section 301(c)(2) of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), the DC Circuit noted that the word “protocols” has many definitions that are not much help. Kennecott Utah Copper Corp., Inc. v. U.S. Dept. of Interior, 88 F.3d. 1191, 1216 (DC Cir. 1996). Section 301(c)(2) of CERCLA prescribed the creation of two types of procedures for conducting natural resources damages assessments. The regulations were to specify (a) “standard procedures for simplified assessments requiring minimal field observation” (the “Type A” rules), and (b) “alternative protocols for conducting assessments in individual cases” (the “Type B” rules). [48] The court upheld the challenged provisions, which were a part of a set of rules establishing a step-by-step procedure to evaluate options based on certain criteria, and to make a decision and document the results.

Taking the considerations above into account, including Congress' instructions to adopt and implement compliance and enforcement protocols, and the Secretary's authority to formulate policy and make rules to fill gaps left, implicitly or explicitly, by Congress, the agency interpreted “protocol” in the context of EISA as authorizing the agency to determine both whether manufacturers have complied with the standards, and to establish suitable and reasonable enforcement mechanisms and decision criteria for non-compliance. Therefore, NHTSA interpreted its authority to develop an enforcement program to include the authority to determine and assess civil penalties for non-compliance.

Several commenters disagreed with this interpretation. Volvo and EMA commented that the penalties proposed by NHTSA exceeded the authority granted to the agency by Congress, and Volvo commented that the fact that Congress did not adopt an entirely new statute for the HD program should be interpreted to mean that provisions adopted for the light-duty program should apply to the HD program as well. Daimler argued that it was likely that EISA did not give NHTSA the authority to assess civil penalties, and Navistar and EMA argued that NHTSA could not have the authority as Congress did not expressly grant it.

NHTSA continues to believe that it is reasonable to interpret “compliance and enforcement protocols” to include authority to impose civil penalties. Where a statute does not specify an approach, the discretion to do so is left to the agency. When Congress has “explicitly left a gap for an agency to fill, there is an express delegation of authority to the agency to elucidate a specific provision of the statute by regulation.”United States. v. Mead, 533 U.S. 218, 227 (2001), quoting Chevron v. NRDC, 467 U.S. 837, 843-44 (1984). The delegation of authority may be implicit rather than express. Id. at 229. NHTSA believes it would be unreasonable to assume that Congress intended to create a hollow regulatory program without a mechanism for effective enforcement. Further, interpreting “enforcement protocols” to mean not more than “compliance protocols” would go against the canon noted above that statutes should not be interpreted in a way that “render[s] language superfluous.”Dobrova v. Holder, 607 F.3d 297, 302 (2d Cir. 2010), quoting Mendez v. Holder 566 F. 3d 316, 321-22 (2d Cir. 2009). The interpretation urged by the commenters would render an entire program superfluous.

Further, NHTSA believes that Congress would have anticipated that compliance and enforcement protocols would include civil penalties for the HD sector, given that penalties are an integral part of a product standards program and given the long precedent of civil penalties for the light-duty sector. The agency disagrees with the argument that the HD program would have appeared in a wholly separate statute if Congress had not intended the penalty program for light-duty to apply to it. The inclusion of the MD/HD program in Title 329 does not mean that Congress intended for the boundaries and differences between the separate sections to be ignored. Rather, this argument leads to the opposite conclusion that the fact that Congress created a new section for the HD program, instead of simply amending the existing light-duty program to include “work trucks and other vehicles” in addition to automobiles, means the agency should assume that Congress acted intentionally when it created two wholly separate programs and respect their distinctions. Therefore, consistent with the statutory interpretation proposed in the NPRM, the final rule includes penalties for non-compliance with the fuel efficiency standards.

(ii) Penalty Levels

NHTSA proposed to adopt penalty levels equal to those in EPA's existing heavy-duty program, in order to provide adequate deterrence as well as consistency with the GHG regulation. The proposed maximum penalty levels were $37,500.00 per vehicle or engine.

Several manufacturers commented that the penalty levels should be limited to those mandated in the light-duty program. Volvo and Daimler argued that Congress intended lower penalties for the HD program than were proposed in the NPRM, because they believed that Congress had expressly or implicitly intended for the HD program to be included in the penalty calculation of Section 32912(b). That section prescribes penalty levels for violators under Section 32902 of “$5 multiplied by each tenth (0.1) of a mile a gallon by which the applicable average fuel economy standard under that section exceeds the average fuel economy,” [49] calculated and applied to automobiles. Volvo further argued that NHTSA was relying upon the CAA as the statutory basis for the penalty levels.

NHTSA recognizes that Section 329 contains a detailed penalty scheme, for light-duty vehicle CAFE standards. However, Section 32902(k)(2) explicitly directs NHTSA to “adopt and implement appropriate test methods, measurement metrics, fuel economy standards, and compliance and enforcement protocols,” in the creation of the new HD program. NHTSA continues to believe that this broad Congressional mandate should be interpreted based on a plain text reading, which includes the authority to determine compliance and enforcement protocols that will be effective and appropriate for this new sector of regulation. NHTSA also believes that reading Section 32912 to apply to the new HD program would contradict Congress' broad mandate for the agency to establish new measurement metrics and a compliance and enforcement program. Further, interpreting the requirement to create “enforcement protocols” for HD vehicles to mean that NHTSA should rely on the enforcement provisions for light-duty vehicles would go against the canon noted above that statutes should not be interpreted in a way that “render[s] language superfluous.”Dobrova v. Holder, 607 F.3d 297, 302 (2d Cir. 2010), quoting Mendez v. Holder 566 F. 3d 316, 321-22 (2d Cir. 2009).

NHTSA believes that Section 32912 does not apply to the new HD program for several other reasons. First, this section uses a fuel economy metric, miles/gallon, while the HD program is built around a fuel consumption metric, per the requirement to develop a “fuel efficiency improvement program” and the agencies' conclusion, supported by NAS, that a fuel consumption metric is a much more reasonable choice than a fuel economy metric for HD vehicles given their usage as work vehicles. Second, this section specifies a calculation for automobiles, a vehicle class which is confined to the light-duty rule. In addition, the HD program prescribes fuel consumption standards, not average fuel economy standards.

Finally, NHTSA believes that if Congress had intended for a pre-determined penalty scheme to apply to the new HD program, it would have been specific. Instead, Congress explicitly directed the agency to develop a new measurement, compliance, and enforcement scheme. Consistent with the statutory interpretation of the duration of the standards, NHTSA believes that if Congress intended for particular penalty levels to be used in Section 32902(k)(3), it would have either included a reference to those levels or included a reference in 32912 to the vehicles and metrics regulated by 32902(k)(3). See Russello v. United States, 464 U.S. 16, 23 (1983), quoting United States v. Wong Kim Bo, 472 F.2d 720, 722 (5th Cir 1972) (“[W]here Congress includes particular language in one section of a statute but omits it in another section of the same Act, it is generally presumed that Congress acts intentionally and purposely in the disparate inclusion or exclusion.”) Instead, the absence of such language could mean either that Congress did not contemplate the specific penalty levels to be used, or that Congress left the choice of specific penalty levels to the agency. See Alliance for Community Media v. F.C.C. 529 F. 3d 763, 779 (6th Cir. 2008) (absence of a statutory deadline in one section but not others meant that Congress authorized but did not require it in that section).

NHTSA believes that, based on EPA's experience regulating this sector for criteria pollutants, the proposed maximum penalty is at an appropriate level to create deterrence for non-compliance, while at the same time, not so high as to create undue hardship for manufacturers. Therefore, the final rule retains the maximum penalty level proposed in the NPRM.

G. Future HD GHG and Fuel Consumption Rulemakings

This final action represents a first regulatory step by NHTSA and EPA to address the multi-faceted challenges of reducing fuel use and greenhouse gas emissions from these vehicles. By focusing on existing technologies and well-developed regulatory tools, the agencies are able to adopt rules that we believe will produce real and important reductions in GHG emissions and fuel consumption within only a few years. Within the context of this regulatory time frame, our program is very aggressive—with limited lead time compared to historic heavy-duty regulations—but pragmatic in the context of technologies that are available and that can be reasonably implemented during the regulatory time frame.

While we are now only finalizing this first step, it is worthwhile to consider how the next regulatory step may be designed. Technologies such as hybrid drivetrains, advanced bottoming cycle engines, and full electric vehicles are promoted in this first step through incentive concepts as discussed in Section IV, but we believe that these advanced technologies will not be necessary to meet the final standards. Today's standards are premised on the use of existing technologies given the short lead time, as discussed in Section III, below. When we begin work to develop a possible next set of regulatory standards, the agencies expect these advanced technologies to be an important part of the regulatory program and will consider them in setting the stringency of any standards beyond the 2018 model year.

We will not only consider the progress of technology in our future regulatory efforts, but the agencies are also committed to fully considering a range of regulatory approaches. To more completely capture the complex interactions of the total vehicle and the potential to reduce fuel consumption and GHG emissions through the optimization of those interactions may require a more sophisticated approach to vehicle testing than we are adopting today for the largest heavy-duty vehicles. In future regulations, the agencies expect to fully evaluate the potential to expand the use of vehicle compliance models to reflect engine and drivetrain performance. Similarly, we intend to consider the potential for complete vehicle testing using a chassis dynamometer, not only as a means for compliance, but also as a complementary tool for the development of more complex vehicle modeling approaches. In considering these more comprehensive regulatory approaches, the agencies will also reevaluate whether separate regulation of trucks and engines remains necessary.

In addition to technology and test procedures, vehicle and engine drive cycles are an important part of the overall approach to evaluating and improving vehicle performance. EPA, working through the WP.29 Global Technical Regulation process, has actively participated in the development of a new World Harmonized Duty Cycle for heavy-duty engines. EPA is committed to bringing forward these new procedures as part of our overall comprehensive approach for controlling criteria pollutant and GHG emissions. However, we believe the important issues and technical work related to setting new criteria pollutant emissions standards appropriate for the World Harmonized Duty Cycle are significant and beyond the scope of this rulemaking. Therefore, the agencies are not adopting these test procedures in this action, but we are ready to work with interested stakeholders to adopt these procedures in a future action.

As noted above, the agencies also intend to further investigate possibilities of expanded credit trading across the heavy-duty sector. As part of this effort, the agencies will investigate the degree to which the issue of credit trading is connected with complete vehicle testing procedures.

As with this program, our future efforts will be based on collaborative outreach with the stakeholder community and will be focused on a program that delivers on our energy security and environmental goals without restricting the industry's ability to produce a very diverse range of vehicles serving a wide range of needs.

II. Final GHG and Fuel Consumption Standards for Heavy-Duty Engines and Vehicles Back to Top

This section describes the standards and implementation dates that the agencies are finalizing for the three categories of heavy-duty vehicles and engines. The agencies have performed a technology analysis to determine the level of standards that we believe will be cost-effective, feasible, and appropriate in the lead time provided. This analysis, described in Section III and in more detail in the RIA Chapter 2, considered for each of the regulatory categories:

  • The level of technology that is incorporated in current new engines and trucks,
  • Forecasts of manufacturers' product redesign schedules,
  • The available data on corresponding CO 2 emissions and fuel consumption for these engines and vehicles,
  • Technologies that would reduce CO 2 emissions and fuel consumption and that are judged to be feasible and appropriate for these vehicles and engines through the 2018 model year,
  • The effectiveness and cost of these technologies, and
  • Projections of future U.S. sales for trucks and engines.

A. What vehicles will be affected?

EPA and NHTSA are finalizing standards for heavy-duty engines and also for what we refer to generally as “heavy-duty vehicles.” In general, these standards will apply for the model year 2014 and later engines and vehicles, although some standards do not apply until 2016 or 2017. The EPA standards will apply throughout the useful life of the engine or vehicle, just as existing criteria emission standards apply throughout the useful life. As noted in Section I, for purposes of this preamble and rules, the term “heavy-duty or “HD” applies to all highway vehicles and engines that are not regulated by the light-duty vehicle, light-duty truck and medium-duty passenger vehicle greenhouse gas and CAFE standards issued for MYs 2012-2016. Thus, in this notice, unless specified otherwise, the heavy-duty category incorporates all vehicles rated with GVWR greater than 8,500 pounds, and the engines that power these vehicles, except for MDPVs. The CAA defines heavy-duty vehicles as trucks, buses or other motor vehicles with GVWR exceeding 6,000 pounds. See CAA section 202(b)(3). In the context of the CAA, the term HD as used in these final rules thus refers to a subset of these vehicles and engines. EISA section 103(a)(3) defines a `commercial medium- and heavy-duty on-highway vehicle' as an on-highway vehicle with GVWR of 10,000 pounds or more. [50] EISA section 103(a)(6) defines a `work truck' as a vehicle that is rated at between 8,500 and 10,000 pounds gross vehicle weight and is not a medium-duty passenger vehicle. [51] Therefore, the term “heavy-duty vehicles” in this rulemaking refers to both work trucks and commercial medium- and heavy-duty on-highway vehicles as defined by EISA. Heavy-duty engines affected by the standards are those that are installed in commercial medium- and heavy-duty vehicles, except for the engines installed in vehicles certified to a complete vehicle emissions standard based on a chassis test, which would be addressed as a part of those complete vehicles, and except for engines used exclusively for stationary power when the vehicle is parked. The agencies' scope is the same with the exception of recreational vehicles (or motor homes), as discussed above. The standards that EPA is finalizing today cover recreational on-highway vehicles, while NHTSA limited its scope in the proposal to not include these vehicles. See Section I.A above.

The NPRM did not include an export exclusion in NHTSA's fuel consumption standards. Oshkosh Corporation commented that NHTSA should add an export exclusion in order to accommodate the testing and delivery needs of manufacturers of vehicles intended for export. NHTSA agrees with this comment and Section 535.3 of the final rule specifies such an exclusion.

EPA and NHTSA are finalizing standards for each of the following categories, which together comprise all heavy-duty vehicles and all engines used in such vehicles. In order to most appropriately regulate the broad range of heavy-duty vehicles and engines, the agencies are setting separate engine and vehicle standards for the combination tractors and Class 2b through 8 vocational vehicles. The engine standards and test procedures for engines installed in the tractors and vocational vehicles are discussed within the preamble sections for combination tractors and vocational vehicles, respectively. The agencies are establishing standards for heavy-duty pickups and vans that apply to the entire vehicle;—there are no separate engine standards.

As discussed in Section IX, the agencies are not adopting GHG emission and fuel consumption standards for trailers at this time. In addition, the agencies are not adopting standards at this time for engine, chassis, and vehicle manufacturers which are small businesses (as defined by the Small Business Administration). More detailed discussion of each regulatory category is included in the subsequent sections below.

B. Class 7 and 8 Combination Tractors

EPA is finalizing CO 2 standards and NHTSA is finalizing fuel consumption standards for new Class 7 and 8 combination tractors. The standards are for the tractor cab, with a separate standard for the engine that is installed in the tractor. Together these standards would achieve reductions of up to 23 percent compared to the model 2010 baseline level. As discussed below, EPA is finalizing its proposal to adopt the existing useful life definitions for Class 7 and 8 tractors and the heavy-duty engines installed in them. NHTSA and EPA are finalizing revised fuel consumption and GHG emissions standards for tractors, and finalizing as proposed engine standards for heavy-duty engines in Class 7 and 8 tractors. The agencies' analyses, as discussed briefly below and in more detail later in this preamble and in the RIA Chapter 2, show that these standards are feasible and appropriate under each agency's respective statutory authorities.

EPA is also finalizing standards to control N 2 O, CH 4, and HFC emissions from Class 7 and 8 combination tractors. The final heavy-duty engine standards for both N 2 O and CH 4 and details of the standard are included in the discussion in Section II.E.1.b and II.E.2.b, respectively. The final air conditioning leakage standards applying to tractor manufacturers to address HFC emissions are discussed in Section II.E.5.

The agencies are finalizing CO 2 emissions and fuel consumption standards for the combination tractors that reflect reductions that can be achieved through improvements in the tractor (such as aerodynamics), tires, and other vehicle systems. The agencies are also finalizing heavy-duty engine standards for CO 2 emissions and fuel consumption that reflect technological improvements in combustion and overall engine efficiency.

The agencies have analyzed the feasibility of achieving the CO 2 and fuel consumption standards, and have identified means of achieving the standards that are technically feasible in the lead time afforded, economically practicable and cost-effective. EPA and NHTSA present the estimated costs and benefits of the standards in Section III. In developing the final rules, the agencies have evaluated the kinds of technologies that could be utilized by engine and tractor manufacturers, as well as the associated costs for the industry and fuel savings for the consumer and the magnitude of the national CO 2 and fuel savings that may be achieved.

The agencies received comments from multiple stakeholders regarding the definition and classification of “combination tractors.” The commenters raised three key issues. First, EMA/TMA, Navistar and DTNA requested that both agencies use the same definition for “tractor” or “truck tractor” in the final rules. EPA proposed a definition for “tractor” in § 1037.801 (see the proposed rule published November 30, 2010, 75 FR 74402) which stated that “tractor” means a vehicle capable of pulling trailers that is not intended to carry significant cargo other than cargo in the trailer, or any other vehicle intended for the primary purpose of pulling a trailer. For purposes of this definition, the term ”cargo” includes permanently attached equipment such as fire-fighting equipment. The following vehicles are tractors: any vehicle sold to an ultimate purchaser with a fifth wheel coupling installed; any vehicle sold to an ultimate purchaser with the rear portion of the frame exposed where the length of the exposed portion is 5.0 meters or less. See § 1037.620 for special provisions related to vehicles sold to secondary vehicle manufacturers in this condition. The following vehicles are not tractors: Any vehicle sold to an ultimate purchaser with an installed cargo carrying feature (for example, this would include dump trucks and cement trucks); any vehicle lacking a fifth wheel coupling sold to an ultimate purchaser with the rear portion of the frame exposed where the length of the exposed portion is more than 5.0 meters.

NHTSA proposed to use the 49 CFR 571.3 definition of “truck tractor” in 49 CFR 535.4 (see the proposed rule published November 30, 2010, 75 FR 74440) which stated that “truck tractor” means a truck designed primarily for drawing other motor vehicles and not so constructed as to carry a load other than a part of the weight of the vehicle and the load so drawn.

Second, EMA/TMA, NTEA and Navistar expressed concerns over, and requested the removal of, the proposed language that all vehicles with sleeper cabs would be classified as tractors. The commenters argued that because there are vocational vehicles manufactured with sleeper cabs that operate as vocational vehicles and not as tractors, those vehicles should be treated the same as all other vocational vehicles. Third, eleven different commenters requested that the agencies subdivide tractors into line-haul tractors and vocational tractors and treat each based upon their operational characteristics: vocational tractors, which operate at lower speeds offroad or in stop-and-go city driving as vocational vehicles; and line-haul tractors, which operate at highway speeds on interstate roadways over long distances, as line-haul tractors.

In response to the first comment, the agencies have decided to standardize the definition of tractor by using the long-standing NHTSA definition of “truck tractor” established in 49 CFR 571.3. 49 CFR 571.3(b) states that a “truck tractor means a truck designed primarily for drawing other motor vehicles and not so constructed as to carry a load other than a part of the weight of the vehicle and the load so drawn.” EPA's proposed definition for “tractor” in the NPRM was similar to the NHTSA definition, but included some additional language to require a fifth wheel coupling and an exposed frame in the rear of the vehicle where the length of the exposed portion is 5.0 meters or less. EMA and Navistar argued that these two different definitions could lead to confusion if the agencies applied their requirements for truck tractors differently from each other. The commenters suggested that the EPA definition was more complicated than necessary, and that the simpler NHTSA definition should be used by both agencies as the base definition of truck tractor.

The agencies agree that the definitions should be standardized and that the NHTSA definition is sufficient and includes the essential requirement that a truck tractor is a truck designed “primarily for drawing other motor vehicles and not so constructed as to carry a load other than a part of the weight of the vehicle and the load so drawn.” EPA's proposed tractor definition was intended to be functionally equivalent to NHTSA's definition based on design, but to be more objective by including the criteria related to “fifth wheels” and exposed rear frame. However, EPA no longer believes that such additional criteria are needed for implementation. NHTSA established the definition for truck tractor in 49 CFR 571.3(b) years ago, [52] and has not encountered any notable problems with its application. Nevertheless, because the NHTSA definition relies more on design intent than EPA's proposed definition, we recognize that there may be some questions regarding how the agencies would apply the NHTSA definition being finalized to certain unique vehicles. For example, many of the common automobile and boat transport trucks may look similar to tractors, but the agencies would not consider them to meet the definition, because they have the capability to carry one or several vehicles as cargo with or without a trailer attached, and therefore are not “constructed as to carry a load other than a part of the weight of the vehicle and the load so drawn.” Similarly, a “dromedary” style truck that has the capability to carry a large load of cargo with or without drawing a trailer would also not qualify as a tractor. [53] Even though these particular vehicles identified could potentially draw other motor vehicles like a trailer, they have also been designed to carry cargo with or without the trailer attached. NHTSA has previously interpreted its definition for “truck tractor” as excluding these specific vehicles like the dromedary and automobile/boat transport vehicles. Tow trucks have also been excluded from the category of truck tractor. On the other hand, it is worth clarifying that designs that allow cargo to be carried in the passenger compartment, the sleeper compartment, or external toolboxes would not exclude a vehicle from the tractor category. The agencies plan to continue with this approach for the HD fuel efficiency and GHG standards, which means that these particular vehicles will be subject to the vocational vehicle standards and not the tractor standards, but vehicles that did meet the definition above for “tractor” will be subject to the combination tractor standards.

In response to the second comment, the agencies have decided not to classify vocational vehicles with sleeper cabs as tractors. In the NPRM, the agencies proposed that vocational vehicles with sleeper cabs be classified as tractors out of concern that a vehicle could initially be manufactured as a straight truck vocational vehicle with a sleeper cab and, soon after introduction into commerce, be converted to a combination tractor as a means to circumvent the Class 8 sleeper cab regulations. Commenters who addressed this issue generally disagreed with the agencies' concern. EMA/TMA, for example, argued that it is expensive and difficult for a manufacturer to change a vehicle from a straight truck to a tractor, because of modifications required to the vehicle, such as to the vehicle's air brake system, and also because of the manufacturers ultimate responsibility for recertification to NHTSA's safety standards. EMA/TMA also argued that straight trucks are often built with sleeper cabs to perform the functions of a vocational type vehicle and not the functions of a line-haul tractor. NTEA also provided an example of a straight truck (Expediter Cab) that can be built with a sleeper cab and a cargo-carrying body, which it argued should be classified as a vocational vehicle and not a tractor.

Upon further consideration, the agencies agree that vocational vehicles with sleeper cabs are more appropriately classified as vocational vehicles than as tractors. The comments discussed above help to illustrate the reasons for building a vocational vehicle with a sleeper cab and the difficulties of converting a straight truck to a tractor. Moreover, 49 U.S.C. Chapter 301 requires any service organization making such modifications to be responsible for recertification to all applicable Federal motor vehicle safety standards, which should act as a further deterrent to anyone contemplating making such a conversion. Together these two items address the agencies' primary reason for proposing the requirement that all vehicles with sleeper cabs be treated as tractors—the concern of circumvention of the tractor standards. However, the agencies will continue to monitor whether it appears that the definitions are creating unintended consequences, and may consider revising the definitions in a future rulemaking to address such issues should any arise. NHTSA and EPA have concluded that the engine and tire improvements required in the vocational category are appropriate for this set of vehicles based on the typical operation of these vehicles. The agencies did not intend to include vocational vehicles with sleeper cabs, such as an Expediter vehicle, into the tractor category in either the NPRM or in this final action, and the agencies' analyses at proposal reflected this intention. Therefore the agencies did not make any adjustments to the program costs and benefits due to this classification change.

In response to the third comment, the agencies have decided to allow manufacturers to exclude certain vocational-type of tractors from the combination tractor standards and instead be subject to the vocational vehicle standards. We discuss below the reasoning underlying this decision, the criteria manufacturers would use in asserting a claim that a vocational tractor should be reclassified as a vocational vehicle, and the procedures the agencies will use to accept or reject manufacturers' claims.

Multiple commenters (Allison Transmission, ATA, CALSTART, Eaton, EMA/TMA, National Solid Waste Management Association, MEMA, Navistar, NADA, RMA, and Volvo) argued that the agencies' proposed classification failed to recognize genuine differences between vocational tractors, which typically operate at lower speeds in stop-and-go city driving, and line-haul tractors, which typically operate at highway speeds on interstate roadways over long distances. Commenters argued that the proposed tractor standards and associated tractor GEM test cycles were derived based primarily upon the operational characteristics of the line-haul tractors, and that technologies that apply to these line-haul tractors, such as improved aerodynamics, vehicle speed limiters and automatic engine shutdown, as well as engine performance for improving emissions and fuel consumption, do not have the same positive impact on fuel consumption when used on tractors. In today's market, as mentioned by Volvo and ATA, we understand that approximately 15 percent, or approximately 15,000 to 20,000, of the Class 7 and 8 tractors could be classified as vocational tractors based upon the work they perform.

The agencies agree that the overall operation of these vocational-types of tractors resembles other vocational vehicles' operation: lower average speed and more stop and go activity than line-haul tractors. Due to their operation style, a FTP certified engine is a better match for these tractors than a SET certified engine, because the FTP cycle uses a lower average speed and more stop and go activity than the SET cycle. In addition, the limited high speed operation leads to minimal opportunities for fuel consumption and CO 2 emissions reductions due to aerodynamic improvements. Conversely, the additional weight of the aerodynamic components could cause an unintended consequence of increasing gram per ton-mile emissions by reducing the amount of payload the vehicle can carry in those applications which are weight-limited. Similarly, the vocational tractors typically do not hotel overnight and therefore will have little to no benefit through the installation of an idle reduction technology.

The agencies received several other comments that described criteria that could be used to distinguish between vocational and non-vocational tractors. Volvo suggested that a tractor could be a vocational tractor if it meets three of five specified features:

(1) A frame Resisting Bending Moment (RBM) greater than or equal to 2,000,000 in-lbs per rail, or rail and liner combination;

(2) An approach angle greater than or equal to 20 degrees nominal design specification, to exclude extended front rails/bumpers for additional equipment (e.g.—pumps, winch, front engine PTO);

(3) Ground clearance greater than or equal to 14 inches as measured unladen from the lowest point of any frame rail or body mounted components, excluding axles and suspension (for HHD and MHD vehicles this is usually considered as the lowest point of the fuel tank/mounting or chassis aerodynamic devices);

(4) A total reduction in high gear greater than or equal to 3.00:1; and

(5) A total reduction in low gear greater than or equal to 57:1.

The approach proposed by Volvo is somewhat similar to the approach NHTSA has for determining if a vehicle is a light truck under the light vehicle CAFE program, in which a vehicle must either have a GVWR greater than 6,000 pounds or have 4-wheel drive, and meet four of the five specified suspension characteristics (approach angle, break-over angle, axle clearance, etc.) to be classified as a light truck. Although we do not believe that the criteria suggested by Volvo are workable for all manufacturers and all applications, we agree that these criteria would reflect a reasonable basis for allowing manufacturers to reclassify their vehicles as vocational tractors.

Two other commenters, EMA/TMA and Navistar, suggested simply that the manufacturer should have the burden of establishing that a tractor is a vocational tractor to the agencies' reasonable satisfaction. The commenters also suggested some factors that could be used to establish that a tractor is actually a “vocational tractor”, including:

(1) A vehicle speed limiter set at 55 mph or less;

(2) Power take-off (PTO) controls;

(3) Extended front frame;

(4) Ground clearance greater than 14 in.;

(5) An approach angle greater than 20 degrees;

(6) Frame RBM greater than 2,000,000 in-lbs.; and

(7) A total gear reduction in low gear greater than 57 and a total gear reduction in top gear greater than 3.

The agencies believe that both suggested approaches have some merit. A rule based on specific criteria as suggested by Volvo could help to minimize the burden on both the manufacturers and the agencies, as manufacturer-written requests for approval and agency approvals of those requests would not be required for each vocational tractor determination whereas the EMA/TMA and Navistar approach requires the opposite namely that each manufacturer would have to justify the determination of each vocational tractor based upon its related design features in a separate petition to the agencies. Neither of the two approaches, which are based on specific criteria, could be used to identify all the tractors that should be classified as vocational tractors. An urban beverage delivery tractor, for example, may not be designed with any of the features mentioned but is used in a vocational vehicle manner. Also, the agencies were concerned about the possibility of manufacturers circumventing the system by incorporating design changes to their line-haul tractors in order to classify them as vocational tractors required to meet less stringent emission and fuel consumption standards. However, at this time the agencies do not believe that circumventing the system is likely, as most of these vocational tractors are built to order and will incorporate the design features required by the customer. Manufacturer vehicle offerings are designed or tailored to suit the particular task of the consumer. The vehicle transport mission including vehicle type, gross vehicle weight, gross combination weight, body style and load handling characteristics, must be considered in the design process. Further, how the vehicle will be utilized, including operating cycles, operating environment and road conditions, is another important consideration in designing a vehicle to accomplish a particular task. The agencies agree that these criteria could also be used as part of a basis for classification. We also note that many of these vehicles have front axle weight ratings greater than 14,600 pounds.

Although the agencies agree that these vocational tractors are operated differently than line-haul tractors and therefore fit more appropriately into the vocational vehicle category, we need to ensure that only tractors that are truly vocational tractors are classified as such. Upon further consideration of the comments received the agencies have decided to allow manufacturers to exclude certain vocational-type tractors from the combination tractor standards, and instead be subject to the standards for vocational vehicles. A vehicle determined by the manufacturer to be a HHD vocational tractor would fall into the HHD vocational vehicle subcategory and be regulated as a vocational vehicle. Similarly, MHD which the manufacturer chooses to reclassify as vocational tractors will be regulated as a MHD vocational vehicle. Specifically, under the provision being finalized at 40 CFR 1037.630 and NHTSA's regulation at 49 CFR 523.2 of today's rules only the following three types of vocational tractors are eligible for reclassification by the manufacturer:

(1) Low-roof tractors intended for intra-city pickup and delivery, such as those that deliver bottled beverages to retail stores.

(2) Tractors intended for off-road operation (including mixed service operation), such as those with reinforced frames and increased ground clearance.

(3) Tractors with a GCWR over 120,000 pounds.

As adopted in 40 CFR 1037.230(a)(1)(xiii), manufacturers will be required to group vocational tractors into a unique family, separate from other combination tractors and vocational vehicles. The provision being adopted in 40 CFR 1037.630 and 49 CFR 535.8 requires the manufacturers to summarize in their applications their basis for believing that the vehicles are eligible for manufacturer reclassification as vocational tractors. EPA and NHTSA could ask for a more detailed description of the basis and EPA would deny an application for certification where it determines the manufacturer lacks an adequate basis for reclassification. The manufacturer would then have to resubmit a modified application to certify the vehicles in question to the tractor standards. Where we determine that a manufacturer is not applying this allowance in good faith, we may require that manufacturer to obtain preliminary approval before using this allowance. This would mean that a manufacturer would need to submit its detailed records to EPA and receive formal approval before submitting its application for certification. The agencies plan to monitor how manufacturers classify their tractor fleets and would reconsider the issue of vocational tractor classification in a future rulemaking if necessary.

Because the difference between some vocational tractors and line-haul tractors is potentially somewhat subjective, we are also including an annual sales limit of 7,000 vocational tractors per manufacturer (based on a three year rolling average) consistent with past production volumes of such vehicles. It is important to note, however, that we do not expect it to be common for manufacturers to be able to justify classifying 7,000 vehicles as vocational tractors in a given model year.

Under the regulations being promulgated in 40 CFR 1037.630 and 49 CFR 523.2, manufacturers will be required to keep records of how they determined that such vehicles qualify as vocational. These records would be more detailed than the description submitted in the applications. Typically, this would be a combination of records of the design features and/or purchasers of the vehicles. The agencies have analyzed the design features that reflect the special needs of these vocational tractors in the three areas noted above—mixed service, heavy haul, and urban delivery. Mixed service applications, such as construction trucks, typically require higher ground clearance and approach angle to accommodate non-paved roads. In addition, they often require frame rails with greater resisting bending moment (RBM) because of the terrain where they operate. [54] The mixed service applications also sometimes require higher front axle weight ratings to accommodate extra loads and/or power take off systems for additional capability. Heavy haul tractors are typically designed with frame rails with extra strength (greater RBM) and higher front axle weight ratings to accommodate the heavy payloads. Often the heavy haul tractors will also have higher ground clearance and greater approach angle for similar reasons as the mixed service applications. Lastly, heavy haul vehicles require a total gear reduction of 57:1 or greater to provide the torque necessary to start the vehicle moving. Urban delivery tractors, such as beverage haulers, have less defined design features that reflect their operational needs. These vehicles offer options which include high RBM rails and front axle weight ratings, but not all beverage trucks are specified with these options. The primary differentiation of these urban delivery tractors is their operation. For this final rulemaking, the agencies projected the costs and benefits of the program considering this provision. As detailed in RIA Section 5.3.2.2.1, the agencies assumed that approximately 20 percent of short-haul tractors sold in 2014 model year and beyond will be vocational tractors. As such, these vehicles will experience benefits reflective of a FTP-certified engine and tire rolling resistance improvement at the technology costs projected in the rules for vocational vehicles.

(1) What is the form of the Class 7 and 8 tractor CO 2 emissions and fuel consumption standards?

As proposed, EPA and NHTSA are finalizing different standards for different subcategories of these tractors with the basis for subcategorization being particular tractor attributes. Attribute-based standards in general recognize the variety of functions performed by vehicles and engines, which in turn can affect the kind of technology that is available to control emissions and reduce fuel consumption, or its effectiveness. Attributes that characterize differences in the design of vehicles, as well as differences in how the vehicles will be employed in-use, can be key factors in evaluating technological improvements for reducing CO 2 emissions and fuel consumption. Developing an appropriate attribute-based standard can also avoid interfering with the ability of the market to offer a variety of products to meet consumer demand. There are several examples of where the agencies have utilized an attribute-based standard. In addition to the example of the light-duty 2012-16 MY vehicle rule, in which the standards are based on the attribute of vehicle “footprint,” the existing heavy-duty highway engine standards for criteria pollutants have for many years been based on a vehicle weight attribute (Light Heavy, Medium Heavy, Heavy Heavy) with different useful life periods, which is a similar approach finalized for the engine GHG and fuel consumption standards discussed below.

Heavy-duty combination tractors are built to move freight. The ability of a vehicle to meet a customer's freight transportation requirements depends on three major characteristics of the tractor: the gross vehicle weight rating (which along with gross combination weight rating (GCWR) establishes the maximum carrying capacity of the tractor and trailer), cab type (sleeper cabs provide overnight accommodations for drivers), and the tractor roof height (to mate tractors to trailers for the most fuel-efficient configuration). Each of these attributes impacts the baseline fuel consumption and GHG emissions, as well as the effectiveness of possible technologies, like aerodynamics, and is discussed in more detail below.

The first tractor characteristic to consider is payload which is determined by a tractor's GVWR and GCWR relative to the weight of the tractor, trailer, fuel, driver, and equipment. Class 7 trucks, which have a GVWR of 26,001-33,000 pounds and a typical GCWR of 65,000 pounds, have a lesser payload capacity than Class 8 trucks. Class 8 trucks have a GVWR of greater than 33,000 pounds and a typical GCWR of greater than 80,000 pounds, the effective weight limit on the federal highway system except in states with preexisting higher weight limits. Consistent with the recommendation in the National Academy of Sciences 2010 Report to NHTSA, [55] the agencies are finalizing a load-specific fuel consumption metric (g/ton-mile and gal/1,000 ton-mile) where the “ton” represents the amount of payload. Generally, higher payload capacity vehicles have better specific fuel consumption and GHG emissions than lower payload capacity vehicles. Therefore, since the amount of payload that a Class 7 vehicle can carry is less than the Class 8 vehicle's payload capacity, the baseline fuel consumption and GHG emissions performance per ton-mile differs between the categories. It is consequently reasonable to distinguish between these two vehicle categories, so that the agencies are finalizing separate standards for Class 7 and Class 8 tractors.

The agencies are not finalizing a single standard for both Class 7 and 8 tractors based on the payload carrying capabilities and assumed typical payload levels of Class 8 tractors alone, as that would quite likely have the perverse impact of increasing fuel consumption and greenhouse gas emissions. Such a single standard would penalize Class 7 vehicles in favor of Class 8 vehicles. However, the greater capabilities of Class 8 tractors and their related greater efficiency when measured on a per ton-mile basis are only relevant in the context of operations where that greater capacity is needed. For many applications such as regional distribution, the trailer payloads dictated by the goods being carried are lower than the average Class 8 tractor payload. In those situations, Class 7 tractors are more efficient than Class 8 tractors when measured by ton-mile of actual freight carried. This is because the extra capabilities of Class 8 tractors add additional weight to vehicles that is only beneficial in the context of its higher capabilities. The existing market already selects for vehicle performance based on the projected payloads. By setting separate standards the agencies do not advantage or disadvantage Class 7 or 8 tractors relative to one another and continue to allow trucking fleets to purchase the vehicle most appropriate to their business practices.

The second characteristic that affects fuel consumption and GHG emissions is the relationship between the tractor cab roof height and the type of trailer used to carry the freight. The primary trailer types are box, flat bed, tanker, bulk carrier, chassis, and low boys. Tractor manufacturers sell tractors in three roof heights—low, mid, and high. The manufacturers do this to obtain the best aerodynamic performance of a tractor-trailer combination, resulting in reductions of GHG emissions and fuel consumption, because it allows the frontal area of the tractor to be similar in size to the frontal area of the trailer. In other words, high roof tractors are designed to be paired with a (relatively tall) box trailer while a low roof tractor is designed to pull a (relatively low) flat bed trailer. The baseline performance of a high roof, mid roof, and low roof tractor differs due to the variation in frontal area which determines the aerodynamic drag. For example, the frontal area of a low roof tractor is approximately 6 square meters, while a high roof tractor has a frontal area of approximately 9.8 square meters. Therefore, as explained below, the agencies are using the roof height of the tractor to determine the trailer type required to be used to demonstrate compliance of a vehicle with the fuel consumption and CO 2 emissions standards. As with vehicle weight classes, setting separate standards for each tractor roof height helps ensure that all tractors are regulated to achieve appropriate improvements, without inadvertently leading to increased emissions and fuel consumption by shifting the mix of vehicle roof heights offered in the market away from a level determined by market foces linked to the actual trailers vehicles will haul in-use.

Tractor cabs typically can be divided into two configurations—day cabs and sleeper cabs. Line haul operations typically require overnight accommodations due to Federal Motor Carrier Safety Administration hours of operation requirements. [56] Therefore, some truck buyers purchase tractor cabs with sleeping accommodations, also known as sleeper cabs, because they do not return to their home base nightly. Sleeper cabs tend to have a greater empty curb weight than day cabs due to the larger cab volume and accommodations, which lead to a higher baseline fuel consumption for sleeper cabs when compared to day cabs. In addition, there are specific technologies, such as extended idle reduction technologies, which are appropriate only for tractors which hotel—such as sleeper cabs. To respect these differences, the agencies are finalizing separate standards for sleeper cabs and day cabs. [57]

The agencies received comments from industry stakeholders (EMA, Allison Transmission, Bosch, and the Heavy-Duty Fuel Efficiency Leadership Group) and ICCT supporting the nine tractor regulatory subcategories proposed and did not receive any comments which supported an alternate classification. Thus, to account for the relevant combinations of these attributes, the agencies are adopting the classification scheme proposed, segmenting combination tractors into the following nine regulatory subcategories:

  • Class 7 Day Cab With Low Roof
  • Class 7 Day Cab With Mid Roof
  • Class 7 Day Cab With High Roof
  • Class 8 Day Cab With Low Roof
  • Class 8 Day Cab With Mid Roof
  • Class 8 Day Cab With High Roof
  • Class 8 Sleeper Cab With Low Roof
  • Class 8 Sleeper Cab With Mid Roof
  • Class 8 Sleeper Cab With High Roof

Adjustable roof fairings are used today on what the agencies consider to be low roof tractors. The adjustable fairings allow the operator to change the fairing height to better match the type of trailer that is being pulled which can reduce fuel consumption and GHG emissions during operation. As proposed, the agencies are treating tractors with adjustable roof fairings as low roof tractors that will tested with the fairing in its lowest position.

(2) What are the Final Class 7 and 8 Tractor and Engine CO 2 Emissions and Fuel Consumption Standards and Their Timing?

In developing the final standards for Class 7 and 8 tractors and for the engines used in these tractors, the agencies have evaluated the current levels of emissions and fuel consumption, the kinds of technologies that could be utilized by truck and engine manufacturers to reduce emissions and fuel consumption from tractors and associated engines, the necessary lead time, the associated costs for the industry, fuel savings for the consumer, and the magnitude of the CO 2 and fuel savings that may be achieved. The technologies on whose performance the final tractor standards are predicated are improvements in aerodynamic design, lower rolling resistance tires, extended idle reduction technologies, and lightweighting of the tractor. The technologies on whose performance the final tractor standards are predicated are engine friction reduction, aftertreatment optimization, and turbocompounding, among others, as described in RIA Chapter 2.4. The agencies' evaluation showed that these technologies are available today, but have very low application rates on current vehicles and engines. EPA and NHTSA also present the estimated costs and benefits of the Class 7 and 8 combination tractor and engine standards in Section III and in RIA Chapter 2, explaining as well the basis for the agencies' conclusion not to adopt standards which are less stringent or more stringent.

(a) Tractor Standards

The agencies are finalizing the following standards for Class 7 and 8 combination tractors in Table 0-1, using the subcategorization approach that was proposed. As explained below in Section III, EPA has determined that there is sufficient lead time to introduce various tractor and engine technologies into the fleet starting in the 2014 model year, and is finalizing standards starting for that model year predicated on performance of those technologies. EPA is finalizing more stringent tractor standards for the 2017 model year which reflect the CO 2 emissions reductions required for 2017 model year engines. (As explained in Section II.B(3)(h)(v) below, engine performance is one of the inputs into the compliance model, and that input will change in 2017 to reflect the 2017 MY engine standards.) The 2017 MY vehicle standards are not premised on tractor manufacturers installing additional vehicle technologies. EPA's final standards apply throughout the useful life period as described in Section V. As proposed, and as discussed further in Section IV below, manufacturers may generate and use credits from Class 7 and 8 combination tractors to show compliance with the standards.

NHTSA is finalizing Class 7 and 8 tractor fuel consumption standards that are voluntary standards in the 2014 and 2015 model years and become mandatory beginning in the 2016 model year, as required by the lead time within EISA. The 2014 and 2015 model year standards are voluntary in that manufacturers are not subject to them unless they opt-in to the standards. [58] Manufacturers that opt in become subject to NHTSA standards for all regulatory categories. NHTSA is also adopting new tractor standards for the 2017 model year which reflect additional improvements in only the heavy-duty engines. As proposed, NHTSA is not implementing an in-use compliance program for fuel consumption because it does not anticipate that there will be notable deterioration of fuel consumption over the useful life of the vehicle.

As explained more fully in Section III and Chapter 2 of the RIA, EPA and NHTSA are not adopting more stringent tractor standards for 2014-2017 MY. The final tractor standards are based on the maximum application rates of available technologies considering the available lead time, and we explain in Section III and Chapter 2 of the RIA that use of additional technologies, or further application of the technologies already mentioned would be either infeasible in the lead time afforded, or uneconomic.

Table II-1—Heavy-Duty Combination Tractor Emissions and Fuel Consumption Standards Back to Top
Day cab Sleeper cab
Class 7 Class 8 Class 8
2014 Model Year CO 2 Grams per Ton-Mile      
Low Roof 107 81 68
Mid Roof 119 88 76
High Roof 124 92 75
2014-2016 Model Year Gallons of Fuel per 1,000 Ton-Mile59      
Low Roof 10.5 8.0 6.7
Mid Roof 11.7 8.7 7.4
High Roof 12.2 9.0 7.3
2017 Model Year CO 2 Grams per Ton-Mile      
Low Roof 104 80 66
Mid Roof 115 86 73
High Roof 120 89 72
2017 Model Year and Later Gallons of Fuel per 1,000 Ton-Mile      
Low Roof 10.2 7.8 6.5
Mid Roof 11.3 8.4 7.2
High Roof 11.8 8.7 7.1

Thestandard values shown above differ somewhat from the proposal, reflecting refinements made to the GEM in response to comments. For example, the agencies received comments from stakeholders concerned that the 2017 MY tractor standards appeared to be backsliding because the reductions were not in line with the reductions expected from the 2017 MY engine standards. The agencies reviewed the issue and found that the engine maps we created in the GEM for the 2017 model year for the proposal did not appropriately reflect the engine improvements. Therefore, the agencies developed new fuel maps for the GEM v2.0 which fully reflect the engine improvements due to the 2017 MY standards. [60] These changes to the GEM did not impact our estimates of the relative effectiveness of the greenhouse gas emissions and fuel consumption improving technologies modeled in this final action nor the overall cost or benefits estimated for these final vehicle standards.

Based on our analysis, the 2017 model year standards for combination tractors and engines represent up to a 23 percent reduction in CO 2 emissions and fuel consumption over a 2010 model year baseline tractor (the baseline sleeper cab does not include idle shutdown technology), as detailed in Section III.A.2. In considering the feasibility of vehicles to comply with the standards, EPA also considered the potential for CO 2 emissions to increase during the regulatory useful life of the product. As we discuss separately in the context of deterioration factor (DF) testing, we have concluded that CO 2 emissions are likely to stay the same or actually decrease in-use compared to new certified configurations. In general, engine and vehicle friction decreases as products wear in leading to reduced parasitic losses and lower CO 2 emissions. Similarly, tire rolling resistance falls as tires wear due to the reduction in tread height. In the case of aerodynamic components, we project no change in performance through the regulatory life of the vehicle since there is essentially no change in their physical form as vehicles age. Similarly, weight reduction elements such as aluminum wheels are not projected to increase in mass through time, and hence, we can conclude will not deteriorate with regard to CO 2 performance in-use. Given all of these considerations, EPA is confident in projecting that the standards finalized today will be technical feasible throughout the regulatory useful life of the program.

(b) Standards for Engines Installed in Combination Tractors

EPA is adopting GHG standards and NHTSA is adopting fuel consumption standards for new heavy-duty engines. This section discusses the standards for engines used in Class 7 and 8 combination tractors and also provides some overall background information. We also note that the agencies are adopting standards for heavy-duty engines used in vocational vehicles. However, as explained further below, compliance with the standards would be measured using different test procedures, corresponding with actual vehicle use, depending on whether the vehicle in which the engine is installed is a Class 7 and 8 combination tractor or a vocational vehicle.

The heavy-duty engine standards vary depending on the type of vehicle in which they are installed, as well as whether the engines are compression ignition or spark ignition. The agencies are adopting separate engine fuel consumption and GHG emissions standards for engines installed in combination tractors versus engines installed in vocational vehicles. Also, for the purposes of the GHG engine emissions and engine fuel consumption standards, the agencies are adopting engine subcategories that match EPA's existing criteria pollutant emissions regulations for heavy-duty highway engines which established four regulatory service classes that represent the engine's intended and primary vehicle application. [61] The Light Heavy-Duty (LHD) diesel engines are intended for application in Class 2b through Class 5 trucks (8,501 through 19,500 pounds GVWR). The Medium Heavy-Duty (MHD) diesel engines are intended for Class 6 and Class 7 trucks (19,501 through 33,000 pounds GVWR). The Heavy Heavy-Duty (HDD) diesel engines are primarily used in Class 8 trucks (33,001 pounds and greater GVWR). Lastly, spark ignition engines (primarily gasoline-powered engines) installed in incomplete vehicles less than 14,000 pounds GVWR and spark ignition engines that are installed in all vehicles (complete or incomplete) greater than 14,000 pounds GVWR are grouped into a single engine service class. The engines in these four regulatory service classes range in size between approximately five liters and sixteen liters. This subcategory structure enables the agencies to set standards that appropriately reflect the technology available for engines installed in each type of vehicle, and that are therefore technologically feasible for these engines. This is the same engine classification scheme the agencies proposed, and there were no adverse comments in response to the proposal.

Heavy heavy-duty diesel and medium heavy-duty diesel engines are used today in combination tractors. The following section refers to the engine standards for these types of engines. This section does not cover gasoline or light heavy-duty diesel engines because they are not used in combination tractors.

In the NPRM, the agencies proposed CO 2 and fuel consumption standards for HD diesel engines to be installed in Class 7 and 8 combination tractors as shown in Table II-2. [62]

Table II-2—Proposed Heavy-duty Diesel Engine Standards for Engines Installed in Tractors Back to Top
Effective 2014 model year Effective 2017 Model Year
CO 2 standard (g/bhp-hr) Voluntary fuel consumption standard (gal/100 bhp-hr) CO 2 standard (g/bhp-hr) Fuel consumption standard (gal/100 bhp-hr)
MHD diesel engine 502 4.93 487 4.78
HHD diesel engine 475 4.67 460 4.52

The agencies proposed to require diesel engine manufacturers to achieve, on average, a three percent reduction in fuel consumption and CO 2 emissions for the 2014 standards over the baseline MY 2010 performance for the engines. [63] The agencies' preliminary assessment of the findings of the 2010 NAS Report and other literature sources indicated that there are technologies available to reduce fuel consumption by this amount in the time frame in the lead time provided by the rules. These technologies include improved turbochargers, aftertreatment optimization, and low temperature exhaust gas recirculation.

The agencies also proposed to require diesel engine manufacturers to achieve, on average, a six percent reduction in fuel consumption and CO 2 emissions for the 2017 MY standards over the baseline MY 2010 performance for MHD and HHD diesel engines required to use the SET-based standard. The agencies stated that additional reductions could likely be achieved through the increased refinement of the technologies projected to be implemented for 2014, plus the addition of turbocompounding, which the agencies' analysis showed would require a longer development time and would not be available in MY 2014. The agencies therefore proposed to provide additional lead time to allow for the introduction of this additional technology, and to wait until 2017 to increase stringency to levels reflecting application of this technology.

The agencies proposed that the MHD and HHD diesel engine CO 2 standards for Class 7 and 8 combination tractors would become effective in MY 2014 for EPA, with more stringent CO 2 standards becoming effective in MY 2017, while NHTSA's fuel consumption standards would become effective in MY 2017, which would be both consistent with the EISA four-year minimum lead-time requirements and harmonized with EPA's timing. The agencies explained that the three-year timing, besides being required by EISA, made sense because EPA's heavy-duty highway engine program for criteria pollutants had begun to provide new emissions standards for the industry in three year increments, which had caused the heavy-duty engine product plans to fall largely into three year cycles reflecting this regulatory environment. To further harmonize with EPA, NHTSA proposed voluntary fuel consumption standards for MHD and HHD diesel engines that are equivalent to EPA CO 2 standards for MYs 2014-2016, allowing manufacturers to opt into the voluntary standards in any of those model years. [64] NHTSA proposed that manufacturers could opt into the program by declaring their intent to opt in to the program at the same time they submit the Pre-Certification Compliance Report, and that a manufacturer opting into the program would begin tracking credits and debits beginning in the model year in which they opt into the program. Both agencies proposed to allow manufacturers to generate and use credits to achieve compliance with the HD diesel engine standards, including averaging, banking, and trading (ABT) and deficit carry-forward. The agencies sought comment on the proposed MHD and HHD engine standards and timing.

The agencies received comments from EMA, Navistar, Cummins, ACEEE, Center for Biological Diversity, Detroit Diesel Corporation, American Lung Association, and the Union of Concerned Scientists. Comments were divided with respect to the proposed levels of stringency. While Cummins and DDC expressed support for the CO 2 and fuel consumption standards for diesel engines, and EMA and Navistar stated the standards could be met if the flexibilities outlined in the NPRM are finalized as proposed, Navistar also stated that the model year 2017 standard may not be feasible since what the agencies characterized as existing technologies are not in production for all manufacturers. In contrast, environmental groups and NGOs stated that the standards did not reflect the potential reductions outlined in the 2010 NAS study and should be more stringent. CBD argued that the standards were not set at the maximum feasible level by definition, because the agencies had said that they were based on the use of existing technologies. In addition, the Center for Neighborhood Technology encouraged the agencies to implement the rules as soon as possible, beginning in the 2012 model year.

In light of the above comments, the agencies re-evaluated the technical basis for the heavy-duty engine standards. The baseline HHD diesel engine performance in 2010 model year on the SET is estimated at 490 g CO 2/bhp-hr (4.81 gal/100 bhp-hr), based on our analysis of confidential data provided by manufacturers and data submitted for the non-GHG emissions certification process. Similarly, the baseline MHD diesel engine performance on the SET cycle is estimated to be 518 g CO 2/bhp-hr (5.09 gallon/100-bhp-hr) for the 2010 model year. Further discussion of the derivation of the baseline can be found in Section III. The agencies believe that the MY 2014 standards can be achieved by most manufacturers through the use of technologies time frame such as improved aftertreatment systems, friction reduction, improved auxiliaries, turbochargers, pistons, and other components. These standards will require diesel engine manufacturers to achieve on average a three percent reduction in fuel consumption and CO 2 emissions over the baseline 2010 model year levels.

However, in recognizing that some manufacturers have engines that would not meet the standard even after applying technologies that improve GHG emissions and fuel consumption by three percent, the agencies are finalizing both the proposed ABT provisions for these engines and also an optional alternate engine standard for 2014 model year, described in more detail below. We believe that concerns expressed by Navistar regarding the 2014 MY standards will be addressed by this alternative standard. The agencies also continue to believe that the 2017 MY standards are achievable using the above approaches and, in the case of SET certified engines, turbocompounding. While Navistar commented that the 2017 MY standard may be challenging because not all manufacturers are presently producing the technologies that may be required to meet the standards, the agencies believe that since manufacturers that may require turbocompounding to meet the standards will not have to do so until 2017 MY, there will be sufficient lead time for all manufacturers to introduce this technology. As noted above, by MY 2017 all MHD and HHD engines installed in combination tractors should have gone through a redesign during which all needed technology can be applied. We note that we are finalizing these standards as proposed based on the assessment that most manufacturers (not just Navistar) will need to make improvements to existing engine systems in order to meet the standards. EPA's HD diesel engine CO 2 emission standards and NHTSA's HD diesel engine fuel consumption standards for engines installed in tractors are presented in Table II-3. As explained above, the first set of standards take effect with MY 2014 (mandatory standards for EPA, voluntary standards for NHTSA), and the second set take effect with MY 2017 (mandatory for both agencies).

Table II-3—Final Heavy-duty Diesel Engine Standards for Engines Installed in Tractors Back to Top
Effective 2014 model year Effective 2017 model year
CO 2 standard (g/bhp-hr) Voluntary fuel consumption standard (gal/100 bhp-hr) CO 2 standard (g/bhp-hr) Fuel consumption standard (gal/100 bhp-hr)
MHD diesel engine 502 4.93 487 4.78
HHD diesel engine 475 4.67 460 4.52

The agencies have also decided to remove NHTSA's proposed Pre-Certification Compliance Report requirement. Instead, manufacturers must submit their decision to opt into NHTSA's voluntary standards for the 2014 through 2016 model years as part of its certification process with EPA. Once a manufacturer opts into the NHTSA program it must stay in the program for all the subsequent optional model years. Manufacturers that opt in become subject to NHTSA standards for all regulatory categories. The declaration statement must be entered prior to or at the same time the manufacturer submits its first application for a certificate of conformity. NHTSA will begin tracking credits and debits beginning in the model year in which a manufacturer opts into its program.

Compliance with the CO 2 emissions and fuel consumption standards will be evaluated based on the SET engine test cycle. In the NPRM, the agencies proposed standards based on the SET cycle for MHD and HHD engines used in tractors due to these engines' primary use in steady state operating conditions (typified by highway cruising). Tractors spend the majority of their operation at steady state conditions, and will obtain in-use benefit of technologies such as turbocompounding and other waste heat recovery technologies during this kind of typical engine operation. Therefore, the engines installed in tractors will be required to meet the standard based on the SET, which is a steady state test cycle.

The agencies gave full consideration to the need for engine manufacturers to redesign and upgrade their engines during the MYs 2014-2017 to meet standards, and fully considered the cost-effectiveness of the standards and the available lead time. The final two-step CO 2 emission and fuel consumption standards recognize the opportunity for technology improvements over the rulemaking time frame, while reflecting the typical engine manufacturers' product plan cycles. Over these four model years there will be an opportunity for manufacturers to evaluate almost every one of their engine models and add technology in a cost-effective way, consistent with existing redesign schedules, to control GHG emissions and reduce fuel consumption. The time-frame and levels for the standards, as well as the ability to average, bank and trade credits and carry a deficit forward for a limited time, are expected to provide manufacturers the time and flexibilities needed to incorporate technology that will achieve the final GHG and fuel consumption standards within the normal engine redesign process. This is an important aspect of the final rules, as it will avoid the much higher costs that would occur if manufacturers needed to add or change technology at times other than these scheduled redesigns. [65] This time period will also provide manufacturers the opportunity to plan for compliance using a multi-year time frame, again in alignment with their normal business practice. Further details on lead time, redesigns and technical feasibility can be found in Section III.

The agencies continue to believe the standards for MHD and HHD diesel engines installed in combination tractors are the most stringent technically feasible in the time frame established in this regulation. The standards will require a 3 percent reduction in engine fuel consumption and GHG emissions in 2014 MY based on improvements to engine components and aftertreatment systems. The 2017 MY standards will require a 6 percent reduction in fuel consumption and GHG emissions over a 2010 model year baseline and assumes the introduction, for some engines, of technologies such as turbocompounding. The standards, however, are not premised on the introduction of technologies that are still in development—such as Rankine bottoming cycle—since these approaches cannot be introduced without further technical development or engine re-design. [66]

Additional discussion on technical feasibility is included in Section III below and in Chapter 2 of the RIA.

The agencies recognize, however, that the schedule of changes for the final standards may not be the most cost-effective one for all manufacturers. The agencies also sought comment as to whether an alternate phase-in schedule for the HD diesel engine standards for combination tractors should be considered. In developing the proposal, heavy-duty engine manufacturers stated that the phase-in of the GHG and fuel consumption standards should be aligned with the On Board Diagnostic (OBD) [67] phase-in schedule, which includes new requirements for heavy-duty vehicles in the 2013 and 2016 model years. The agencies did not adopt this suggestion in the proposal, explaining that the credit averaging, banking and trading provisions would provide manufacturers with considerable flexibility to manage their GHG and fuel efficiency standard compliance plans—including the phase-in of the new heavy-duty OBD requirements—but requested comment on whether EPA and NHTSA should provide an alternate phase-in schedules that would more explicitly accommodate this request in the event that manufacturers did not agree that the ABT provisions mitigated their concern about the GHG/fuel consumption standard phase-in. See 75 FR at 74178.

In response, Cummins, Engine Manufacturers Association, and DTNA commented that their first choice was a delay in the OBD effective date for one year to the 2014 model year. The industry's second choice was to provide manufacturers with an optional GHG and fuel consumption phase-in that aligns their product development plans with their current plans to meet the OBD regulations for EPA and California in the 2013 and 2016 model years. These commenters argued that meeting the OBD regulation in the 2013 model year already poses a significant challenge, and that having to meet GHG and fuel consumption standards beginning in 2014 could require them to redesign and recertify their products just one year later. They argued that bundling design changes where possible can reduce the burden on industry for complying with regulations, so aligning the introduction of the OBD, GHG, and fuel consumption standards could help reduce manufacturers' burden for product development, validation and certification.

In order to provide additional flexibility for manufacturers looking to align their technology changes with multiple regulatory requirements, the agencies are finalizing an alternate “OBD phase-in” option for meeting the standards for MHD and HHD diesel engines installed in tractors (in addition to engines installed in vocational vehicles as noted below in Section II.D), which delivers equivalent CO 2 emissions and fuel consumption reductions as the primary standards for the engines built in the 2013 through 2017 model years, as shown in Table II-4. The optional OBD phase-in schedule requires that engines built in the 2013 and 2016 model years to achieve greater reductions than the engines built in those model years under the primary program, but requires fewer reductions for the engines built in the 2014 and 2015 model years.

Table II-4—Comparison of CO 2 reductions for the HHD and MHD Tractor Standards Under the Alternative OBD Phase-In and Primary Phase-In Back to Top
HHD Tractor engines MHD Tractor engines
Primary phase-in standard (g/bhp-hr) Optional phase-in standard (g/bhp-hr) Difference in lifetime CO 2 engine emissions (MMT) Primary phase-in standard (g/bhp-hr) Optional phase-in standard (g/bhp-hr) Difference in lifetime CO 2 engine emissions (MMT)
Baseline 490 490 518 518
2013 MY Engine 490 485 14 518 512 17
2014 MY Engine 475 485 −28 502 512 −28
2015 MY Engine 475 485 −28 502 512 −28
2016 MY Engine 475 460 42 502 487 42
2017 MY Engine 460 460 0 487 487 0
Net Reductions (MMT) 0 3

The technologies for the 2013 model year optional standard include a subset of technologies that could be used to meet the primary 2014 model year standard. The agencies believe this approach is appropriate because the shorter lead time provided for manufacturers selecting this option limits the technologies which can be applied. However, in order to maintain equivalent CO 2 emissions and fuel consumption reduction over the 2013 through 2017 model year period, it is necessary for the 2016 model year standard to be equal to the 2017 model year standard, using the same technology paths described for the primary engine program. If a manufacturer selects this optional phase-in, then the engines must be certified starting in the 2013 model year and continue using this phase-in through 2016 model year. That is, once electing this compliance path, manufacturers must adhere to it. [68] Manufacturers may opt into the optional OBD phase-in through the voluntary NHTSA program, but must opt in in the 2013 model year and continue using this phase-in through the 2016 model year. Manufacturers that opt in to the voluntary NHTSA program in 2014 and 2015 will be required to meet the primary phase-in schedule and may not adopt the OBD phase-in option. Table II-5 below presents the final HD diesel engine CO 2 emission standards under the “OBD phase-in” option.

Table II-5—Optional Heavy-Duty Engine Standard Phase-in Schedule for Tractor Engines Back to Top
MHD Diesel engine HHD Diesel engine
Effective 2013 Through 2015 Model Year    
CO 2 Standard (g/bhp-hr) 512 485
Voluntary Fuel Consumption Standard (gallon/100 bhp-hr) 5.03 4.76
Effective 2016 Model Year and Later    
CO 2 Standard (g/bhp-hr) 487 460
Fuel Consumption (gallon/100 bhp-hr) 4.78 4.52

Although the agencies believe that the standards for the HD diesel engines installed in combination tractors are generally appropriate, cost-effective, and technologically feasible in the rulemaking time frame, we also recognize that when regulating a category of engines for the first time, there will be individual products that may deviate significantly from the baseline level of performance, whether because of a specific approach to criteria pollution control, or due to engine calibration for specific applications or duty cycles. In the current fleet of 2010 and 2011 model year engines used in combination tractors, NHTSA and EPA understand that there is a relatively small group of legacy engines that are up to approximately 25 percent worse than the average baseline for other engines. For this group of legacy MHD and HHD diesel engines installed in tractors, when compared to the typical performance levels of the majority of the engines in the fleet and the fuel consumption/GHG emissions reductions that the majority of engines would achieve through increased application of technology, the same reduction from the industry baseline may not be possible at reasonably comparable cost given the same amount of lead-time, because these products may require a total redesign in order to meet the standards. Manufacturers of the MHD and HHD diesel engines installed in tractors with atypically high baseline CO 2 and fuel consumption levels may also, in some instances, have a limited line of engines across which to average performance to meet the generally-applicable standards.

To account for this possibility, the agencies requested comment in the NPRM on the establishment of an optional alternative MHD and HHD engine standard for those engines installed in combination tractors which would be set at 3 percent below a manufacturer's 2011 engine baseline emissions and fuel consumption, or alternatively, at 2 percent below a manufacturer's 2011 baseline. The agencies also requested comment on extending this optional standard one year (to the 2017 MY) for a single engine family at a 6 percent level below the 2011 baseline. [69] This option would not be available unless and until a manufacturer had exhausted all available credits and credit opportunities, and engines under the optional standard could not generate credits.

In comments to the NPRM, Navistar supported the alternative engine standard, but recommended that it be set at 2 percent below the manufacturer's 2011 baseline. They also supported the extension to 2017 MY at 6 percent. Navistar provided CBI in support of its comments. Volvo, DTNA, environmental groups, NGOs, and the New York State Department of Environmental Conservation opposed the optional engine standard, arguing that existing flexibilities are sufficient to allow compliance with the standards and that all manufacturers should be held to the same standards.

Based on the CBI submitted by Navistar, the agencies found that a large majority of the HD diesel engines used in Class 7 and 8 combination tractors were relatively close to the average baseline, with some above and some below, but also that some legacy MHD and HDD diesel engines were far enough away from the baseline that they could not meet the generally-applicable standards with application of technology that would be available for those specific engines by 2014. The agencies continue to believe that an interim alternative standard is needed for these products, and that an interim standard reflects a legitimate difference between products starting from different fuel consumption/GHG emitting baselines. As explained in the proposal, it is legally permissible to accommodate short term lead time constraints with alternative standards. Commenters did not dispute that there are legacy engine families with significantly higher CO 2 emissions and fuel consumption baselines, and that these engines require longer lead time to meet the principal standards in the early model years of the program. Although the agencies acknowledge the view that all manufacturers should be subject to the same burden for meeting the primary standards, the agencies believe that, in the initial years of a new program, additional flexibilities should be provided. The GHG standards and fuel consumption standards are first-time standards for these engines, so the possibility of significantly different baselines is not unexpected. [70] Moreover, the agencies do not believe that the alternative standard affords a relative competitive advantage to the higher emitting legacy engines: the same level of improvement at the same cost will be required of those tractor engines, and in addition, by 2017 MY, those tractor engines will be required to make the additional improvements to meet the same standards as other engines. We believe that the concern expressed by Navistar regarding the 2014 MY standards will be addressed by this alternative. The agencies also continue to believe the 2017 MY standards are achievable using the above approaches and, in the case of MHD and HHD engines installed in tractors, turbocompounding. While Navistar commented that the 2017 MY standard may be challenging, the agencies believe that since manufacturers which may need to use turbocompounding to meet the standards will not have to do so until 2017 MY, there will be sufficient lead time for all engine manufacturers to introduce this technology. Thus, the agencies are finalizing a regulatory alternative whereby a manufacturer, for an interim period of the 2014-2016 model years, would have the option to comply with a unique standard based on a three percent reduction from an individual engine's own 2011 model year baseline level. Our assessment is that this three percent reduction is appropriate given the potential for manufacturers to apply similar technology packages with similar cost to what we have estimated for the primary program. This is similar to EPA's approach in the light-duty rule for handling a certain subset of vehicles that were deemed unable to meet the generally-applicable GHG standards during the 2012-2015 time frame due to higher initial baseline conditions, and which therefore needed alternate standards in those model years. [71]

The agencies stress that this is a temporary and limited option being implemented to address diverse manufacturer needs associated with complying with this first phase of the regulations. As codified in 40 CFR 1036.620 and 49 CFR 535.5(d), this optional standard will be available only for the 2014 through 2016 model years, because we believe that manufacturers will have had ample opportunity to make appropriate changes to bring their product performance into line with the rest of the industry after that time. As proposed, the final rules require that manufacturers making use of these provisions for the optional standard would need to exhaust all credits available to this averaging set prior to using this flexibility and would not be able to generate emissions credits from other engines in the same regulatory averaging set as the engines complying using this alternate approach.

The agencies note again that manufacturers choosing to utilize this option in MYs 2014-2016 will have to make a greater relative improvement in MY 2017 than the rest of the industry, since they will be starting from a worse level—for compliance purposes, emissions from engines certified and sold at the three percent level will be averaged with emissions from engines certified and sold at more stringent levels to arrive at a weighted average emissions for all engines in the subcategory. Again, this option can only be taken if all other credit opportunities have been exhausted and the manufacturer still cannot meet the primary standards. If a manufacturer chooses this option to meet the EPA emission standards in the MY 2014-2016, and wants to opt into the NHTSA fuel consumption program in these same MYs it must follow the exact path followed under the EPA program utilizing equivalent fuel consumption standards. Since the NHTSA standards are optional in 2014, manufacturers may choose not to adopt either the alternative engine standard or the regular voluntary standard by not participating in the NHTSA program in 2014 and 2015.

Some commenters argued that manufacturers could game the standard by establishing an artificially high 2011 baseline emission level. This could be done, for example, by certifying an engine with high fuel consumption and GHG emissions that is either: (1) Not sold in significant quantities; or (2) later altered to emit fewer GHGs and consume less fuel through service changes. In order to mitigate this possibility, the agencies are requiring that the 2011 model year baseline must be developed by averaging emissions over all engines in an engine family certified and sold for that model year so as to prevent a manufacturer from developing a single high GHG output engine solely for the purpose of establishing a high baseline. As an alternative, if a manufacturer does not certify all engine families in an averaging set to the alternate standards, then the tested configuration of the engine certified to the alternate standard must have the same engine displacement and its rated power within 5 percent of the highest rated power of the baseline tested configuration. In addition, the tested configuration of the engine certified to the alternate standard must be a configuration sold to customers. These three requirements will prevent a manufacturer from producing an engine with an artificially high power rating and therefore produce artificially low grams of CO 2 emissions and fuel consumption per brake horsepower. In addition, the tested configurations must have a BSFC equivalent to or better than all other configurations within the engine family which will prevent a manufacturer from creating a baseline configuration with artificially high CO 2 emissions and fuel consumption.

(c) In-Use Standards

Section 202(a)(1) of the CAA specifies that EPA is to adopt emissions standards that are applicable for the useful life of the vehicle. The in-use standards that EPA is finalizing would apply to individual vehicles and engines. NHTSA is adopting an approach which does not include in-use standards.

EPA proposed that the in-use standards for heavy-duty engines installed in tractors be established by adding an adjustment factor to the full useful life emissions and fuel consumption results projected in the EPA certification process to address measurement variability inherent in comparing results among different laboratories and different engines. The agency proposed a two percent adjustment factor and requested comments and additional data during the proposal to assist in developing an appropriate factor level. The agency received additional data during the comment period which identified production variability which was not accounted for at proposal. Details on the development of the final adjustment factor are included in RIA Chapter 3. Based on the data received, EPA determined that the adjustment factor in the final rules should be higher than the proposed level of two percent. EPA is finalizing a three percent adjustment factor for the in-use standard to provide a reasonable margin for production and test-to-test variability that could result in differences between the initial emission test results and emission results obtained during subsequent in-use testing.

We are finalizing regulatory text (in § 1036.150) to allow engine manufacturers to used assigned deterioration factors (DFs) without performing their own durability emission tests or engineering analysis. However, the engines would still be required to meet the standards in actual use without regard to whether the manufacturer used the assigned DFs. This allowance is being adopted as an interim provision applicable only for this initial phase of standards.

Manufacturers will be allowed to use an assigned additive DF of 0.0 g/bhp-hr for CO 2 emissions from any conventional engine (i.e., an engine not including advance or innovative technologies). Upon request, we could allow the assigned DF for CO 2 emissions from engines including advance or innovative technologies, but only if we determine that it would be consistent with good engineering judgment. We believe that we have enough information about in-use CO 2 emissions from conventional engines to conclude that they will not increase as the engines age. However, we lack such information about the more advanced technologies.

EPA is also finalizing the proposed provisions requiring that the useful life for these engine and vehicles with respect to GHG emissions be set equal to the respective useful life periods for criteria pollutants. EPA is adopting provisions where the existing engine useful life periods, as included in Table II-6, be broadened to include CO 2 emissions for both engines (See 40 CFR 1036.108(d)) and tractors (See 40 CFR 1037.105).

Table II-6—Tractor and Engine Useful Life Periods Back to Top
Years Miles
Medium Heavy-Duty Diesel Engines 10 185,000
Heavy Heavy-Duty Diesel Engines 10 435,000
Class 7 Tractors 10 185,000
Class 8 Tractors 10 435,000

(3) Test Procedures and Related Issues

The agencies are finalizing a complete set of test procedures to evaluate fuel consumption and CO 2 emissions from Class 7 and 8 tractors and the engines installed in them. Consistent with the proposal, the test procedures related to the tractors are all new, while the engine test procedures already established were built substantially on EPA's current non-GHG emissions test procedures, except as noted. This section discusses the final simulation model developed for demonstrating compliance with the tractor standard and the final engine test procedures.

(a) Vehicle Simulation Model

We are finalizing as proposed separate engine and vehicle-based emission standards to achieve the goal of reducing emissions and fuel consumption for both combination tractors and engines. Engine manufacturers are subject to the engine standards while the Class 7 and 8 tractor manufacturers are required to install certified engines in their tractors. The tractor manufacturer is also subject to a separate vehicle-based standard which utilizes a vehicle simulation model to evaluate the impact of the tractor cab design to determine compliance with the tractor standard.

A simulation model, in general, uses various inputs to characterize a vehicle's properties (such as weight, aerodynamics, and rolling resistance) and predicts how the vehicle would behave on the road when it follows a driving cycle (vehicle speed versus time). On a second-by-second basis, the model determines how much engine power needs to be generated for the vehicle to follow the driving cycle as closely as possible. The engine power is then transmitted to the wheels through transmission, driveline, and axles to move the vehicle according to the driving cycle. The second-by-second fuel consumption of the vehicle, which corresponds to the engine power demand to move the vehicle, is then calculated according to a fuel consumption map in the model. Similar to a chassis dynamometer test, the second-by-second fuel consumption is aggregated over the complete drive cycle to determine the fuel consumption of the vehicle.

Consistent with the proposal, NHTSA and EPA are finalizing a procedure to evaluate fuel consumption and CO 2 emissions respectively through a simulation of whole-vehicle operation, consistent with the NAS recommendation to use a truck model to evaluate truck performance. [72] The EPA developed the Greenhouse gas Emissions Model (GEM) for the specific purpose of this rulemaking to evaluate truck performance. The GEM is similar in concept to a number of vehicle simulation tools developed by commercial and government entities. The model developed by the EPA and finalized here was designed for the express purpose of vehicle compliance demonstration and is therefore simpler and less configurable than similar commercial products. This approach gives a compact and quicker tool for vehicle compliance without the overhead and costs of a more sophisticated model. Details of the model are included in Chapter 4 of the RIA. The agencies are aware of several other simulation tools developed by universities and private companies. Tools such as Argonne National Laboratory's Autonomie, Gamma Technologies' GT-Drive, AVL's CRUISE, Ricardo's VSIM, Dassault's DYMOLA, and University of Michigan's HE-VESIM codes are publicly available. In addition, manufacturers of engines, vehicles, and trucks often have their own in-house simulation tools. The agencies sought comments regarding other software packages which would better serve the compliance purposes of the rules than the GEM, but did not receive any recommendations.

The GEM is designed to focus on the inputs most closely associated with fuel consumption and CO 2 emissions—i.e., on those which have the largest impacts such as aerodynamics, rolling resistance, weight, and others.

EPA has validated the GEM based on the chassis test results from two combination tractors tested at Southwest Research Institute. The validation work conducted on this vehicle was representative of the other Class 7 and 8 tractors. Many aspects of one tractor configuration (such as the engine, transmission, axle configuration, tire sizes, and control systems) are similar to those used on the manufacturer's sister models. For example, the powertrain configuration of a sleeper cab with any roof height is similar to the one used on a day cab with any roof height. Overall, the GEM predicted the fuel consumption and CO 2 emissions within 2 percent of the chassis test procedure results for three test cycles—the California ARB Transient cycle, 65 mph cruise cycle, and 55 mph cruise cycle. These cycles are the ones the agencies are utilizing in compliance testing. Since the time of the proposal, the EPA also conducted a validation of the GEM relative to a commonly used vehicle simulation software, GT-Power. The results of this validation found that the two software programs predicted the fuel efficiency of each subcategory of tractor to be within 2 percent. Test to test variation for heavy-duty vehicle chassis testing can be higher than 4 percent due to driver variation alone. The final simulation model is described in greater detail in Chapter 4 of the RIA and is available for download by at (http://www.epa.gov/otaq/climate/regulations.htm).

After proposal, the agencies conducted a peer review of GEM version 1.0 which was proposed. In addition, we requested comment on all aspects of this approach to compliance determination in general and to the use of the GEM in particular. The agencies received comments from stakeholders and made changes for the release of GEM v2.0 to address concerns raised in the comments, along with the comments received during the peer review process. The most noticeable changes to the GEM include improvements to the graphical user interface (GUI). In response to comments, the agencies have reduced the amount of information required in the Identification section; linked the inputs to the selected subcategory while graying-out the items that are not applicable to the subcategory; and added batch modeling capability to reduce the compliance burden to manufacturers. In addition, substantial work went into model validations and benchmarking against vehicle test data and other commonly used vehicle simulation models.

The model also includes a new driver model, a simplified electric system model, and revised engine fuel maps to better reflect the 2017 model year engine standards. The model in the final rulemaking uses the targeted vehicle driving speed to estimate vehicle torque demand at any given time, and then the power required to drive the vehicle is derived to estimate the required accelerator and braking pedal positions. If the driver misses the vehicle speed target, a speed correction logic controlled by a PID controller is applied to adjust necessary accelerator and braking pedal positions in order to match targeted vehicle speed at every simulation time step. The enhanced driver model used in the final rulemaking with its feed-forward driver controls more realistically models driving behavior. The GEM v1.0, the proposed version of the model, had four individual components to model the electric system—starter, electrical energy system, alternator, and electrical accessory. For the final rulemaking, the GEM v2.0 has a single electric system model with a constant power consumption level. Based on comments received, the agencies revisited the 2017 model year proposed fuel maps, specifically the low load area, which was extrapolated during the proposal and (incorrectly) generated negative improvements. The agencies redeveloped the fuel maps for the final rulemaking to better predict the fuel consumption of engines in this area of the fuel consumption map. Details of the changes are included in RIA Chapter 4.

To demonstrate compliance, a Class 7 and 8 tractor manufacturer will measure the performance of specified tractor systems (such as aerodynamics and tire rolling resistance), input the values into the GEM, and compare the model's output to the standard. The rules require that a tractor manufacturer provide the inputs for each of following factors for each of the tractors it wishes to certify under CO 2 standards and for establishing fuel consumption values: Coefficient of Drag, Tire Rolling Resistance Coefficient, Weight Reduction, Vehicle Speed Limiter, and Extended Idle Reduction Technology. These are the technologies on which the agencies' own feasibility analysis for these vehicles is predicated. An example of the GEM input screen is included in Figure II-1.

For the aerodynamic assessment, tire rolling resistance, and tractor weight reduction, the input values for the simulation model will be determined by the manufacturer through conducting tests using the test procedures finalized by the agencies in this action and described below. The agencies are allowing several testing alternatives for aerodynamic assessment referenced back to a coastdown test procedure, a single procedure for determination of the coefficient of rolling resistance (CRR) for tires, and a prescribed method to determine tractor weight reduction. The agencies have finalized defined model inputs for determining vehicle speed limiter and extended idle reduction technology benefits. The other aspects of vehicle performance are fixed within the model as defined by the agencies and are not varied for the purpose of compliance.

(b) Metric

Test metrics which are quantifiable and meaningful are critical for a regulatory program. The CO 2 and fuel consumption metric should reflect what we wish to control (CO 2 or fuel consumption) relative to the clearest value of its use: in this case, carrying freight. It should encourage efficiency improvements that will lead to reductions in emissions and fuel consumption during real world operation. The agencies are finalizing standards for Class 7 and 8 combination tractors that would be expressed in terms of moving a ton (2,000 pounds) of freight over one mile. Thus, NHTSA's final fuel consumption standards for these trucks would be represented as gallons of fuel used to move one ton of freight 1,000 miles, or gal/1,000 ton-mile. EPA's final CO 2 vehicle standards would be represented as grams of CO 2 per ton-mile. The model converts CO 2 emissions to fuel consumption using the CO 2 grams per ton mile estimated by GEM and an assumed 10,180 grams of CO 2 per gallon of diesel fuel.

This approach tracks the recommendations of the NAS report. The NAS panel concluded, in their report, that a load-specific fuel consumption metric is appropriate for HD trucks. The panel spent considerable time explaining the advantages of and recommending a load-specific fuel consumption approach to regulating the fuel efficiency of heavy-duty trucks. See NAS Report pages 20 through 28. The panel first points out that the nonlinear relationship between fuel economy and fuel consumption has led consumers of light-duty vehicles to have difficulty in judging the benefits of replacing the most inefficient vehicles. The panel describes an example where a light-duty vehicle can save the same 107 gallons per year (assuming 12,000 miles travelled per year) by improving one vehicle's fuel efficiency from 14 to 16 mpg or improving another vehicle's fuel efficiency from 35 to 50.8 mpg. The use of miles per gallon leads consumers to undervalue the importance of small mpg improvements in vehicles with lower fuel economy. Therefore, the NAS panel recommends the use of a fuel consumption metric over a fuel economy metric. The panel also describes the primary purpose of most heavy-duty vehicles as moving freight or passengers (the payload). Therefore, they concluded that the most appropriate way to represent an attribute-based fuel consumption metric is to normalize the fuel consumption to the payload.

With the approach to compliance NHTSA and EPA are adopting, a default payload is specified for each of the tractor categories suggesting that a gram per mile metric with a specified payload and a gram per ton-mile metric would be effectively equivalent. The primary difference between the metrics and approaches relates to our treatment of mass reductions as a means to reduce fuel consumption and greenhouse gas emissions. In the case of a gram per mile metric, mass reductions are reflected only in the calculation of the work necessary to move the vehicle mass through the drive cycle. As such it directly reduces the gram emissions in the numerator since a vehicle with less mass will require less energy to move through the drive cycle leading to lower CO 2 emissions. In the case of Class 7 and 8 tractors and our gram/ton-mile metric, reductions in mass are reflected both in less mass moved through the drive cycle (the numerator) and greater payload (the denominator). We adjust the payload based on vehicle mass reductions because we estimate that approximately one third of the time the amount of freight loaded in a trailer is limited not by volume in the trailer but by the total gross vehicle weight rating of the tractor. By reducing the mass of the tractor the mass of the freight loaded in the vehicle can go up. Based on this general approach, it can be estimated that for every 1,200 pounds in mass reduction across all Class 7 and 8 tractors on the road, that total vehicle miles traveled, and therefore trucks on the road, could be reduced by one percent. Without the use of a per ton-mile metric it would not be clear or straightforward for the agencies to reflect the benefits of mass reduction from large freight carrying vehicles that are often limited in the freight they carry by the gross vehicle weight rating of the vehicle. There was strong consensus in the public comments for adopting the proposed metrics for tractors.

(c) Vehicle Aerodynamic Assessment

The aerodynamic drag of a vehicle is determined by the vehicle's coefficient of drag (Cd), frontal area, air density and speed. As noted in the NPRM, quantifying truck aerodynamics as an input to the GEM presents technical challenges because of the proliferation of vehicle configurations, the lack of a clearly preferable standardized test method, and subtle variations in measured aerodynamic values among various test procedures. Class 7 and 8 tractor aerodynamics are currently developed by manufacturers using a range of techniques, including wind tunnel testing, computational fluid dynamics, and constant speed tests.

Consistent with our discussion at proposal, we believe a broad approach allowing manufacturers to use these multiple different test procedures to demonstrate aerodynamic performance of its tractor fleet is appropriate given that no single test procedure is superior in all aspects to other approaches. Allowing manufacturers to use multiple test procedures and modeling coupled with good engineering judgment to determine aerodynamic performance is consistent with the current approach used in determining representative road load forces for light-duty vehicle testing (40 CFR 86.129-00(e)(1)). However, we also recognize the need for consistency and a level playing field in evaluating aerodynamic performance.

The agencies are retaining an aerodynamic bin structure for the final rulemaking, but are adjusting the method used to determine the bins. To address the consistency and level playing field concerns, NHTSA and EPA proposed that manufacturers use a two-part screening approach for determining the aerodynamic inputs to the GEM. The first part would have required the manufacturers to assign each vehicle aerodynamic configuration based on descriptions of vehicle characteristics to one of five aerodynamics bins created by EPA and NHTSA. The proposed assignment by bin would have fixed (by rule) the aerodynamic characteristics of the vehicle. However, the agencies, while working with industry, concluded for the final rulemaking that an approach which identified a reference aerodynamic test method and a procedure to align results from other aerodynamic test procedures with the reference method is a simpler, more accurate approach than deciphering and interpreting written descriptions of aerodynamic components.

Therefore, we are finalizing an approach, as described in Section V.B.3.d and § 1037.501, which uses an enhanced coastdown procedure as a reference method and defines a process for manufacturers to align drag results from each of their own test methods to the reference method results. Manufacturers will be able to use any aerodynamic evaluation method in demonstrating a vehicle's aerodynamic performance as long as the method is aligned to the reference method. The results from the aerodynamic testing will be the single determining factor for aerodynamic bin assignments.

EPA and NHTSA recognize that wind conditions, most notably wind direction, have a greater impact on real world CO 2 emissions and fuel consumption of heavy-duty trucks than of light-duty vehicles. As noted in the NAS report, [73] the wind average drag coefficient is about 15 percent higher than the zero degree coefficient of drag. In addition, the agencies received comments that supported the use of wind averaged drag results for the aerodynamic determination. The agencies considered finalizing the use of a wind averaged drag coefficient in this regulatory program, but ultimately decided to finalize drag values which represent zero yaw (i.e., representing wind from directly in front of the vehicle, not from the side) instead. We are taking this approach recognizing that the reference method is coastdown testing which is not capable of determining wind averaged yaw. Wind tunnels are currently the only tool which can accurately assess the influence of wind speed and direction on a vehicle's aerodynamic performance. The agencies recognize, as NAS did, that the results of using the zero yaw approach may result in fuel consumption predictions that are offset slightly from real world performance levels, not unlike the offset we see today between fuel economy test results in the CAFE program and actual fuel economy performance observed in-use. We believe this approach will not impact overall technology effectiveness or change the kinds of technology decisions made by the tractor manufacturers in developing equipment to meet our final standards. However, the agencies are adopting provisions which allow manufacturers to generate credits reflecting performance of technologies which improve the aerodynamic performance in crosswind conditions, similar to those experienced by vehicles in use through innovative technologies, as described in Section IV.

As just noted, the agencies are adopting an approach for this final action where the manufacturer would determine a tractor's aerodynamic drag force using their own aerodynamic assessment tools and correlating the results back to the reference aerodynamic test method of enhanced coastdown testing. The manufacturer determines the appropriate predefined aerodynamic bin based on the correlated test results and then inputs the predefined Cd value for that aerodynamic bin into the GEM. Coefficient of drag and frontal area of the tractor-trailer combination go hand-in-hand to determine the force required to overcome aerodynamic drag. The agencies proposed that the Cd value would be a GEM input derived by the manufacturer and that the agencies would specify the vehicle's frontal area for each regulatory subcategory. The agencies sought and received comment recommending an alternate approach where the aerodynamic input tables (as shown in Table 0-7 and Table 0-8) represent the drag force as defined as Cd multiplied by the frontal area. Because both approaches are essentially equivalent and the use of CdA more directly relates back to the aerodynamic testing, the agencies are finalizing the use of CdA as recommended by manufacturers.

The agencies are finalizing aerodynamic technology bins which divide the wide spectrum of tractor aerodynamics into five bins (i.e., categories) for high roof tractors. The first high roof category, Bin I, is designed to represent tractor bodies which prioritize appearance or special duty capabilities over aerodynamics. These Bin I trucks incorporate few, if any, aerodynamic features and may have several features which detract from aerodynamics, such as bug deflectors, custom sunshades, B-pillar exhaust stacks, and others. The second high roof aerodynamics category is Bin II which roughly represents the aerodynamic performance of the average new tractor sold today. The agencies developed this bin to incorporate conventional tractors which capitalize on a generally aerodynamic shape and avoid classic features which increase drag. High roof tractors within Bin III build on the basic aerodynamics of Bin II tractors with added components to reduce drag in the most significant areas on the tractor, such as integral roof fairings, side extending gap reducers, fuel tank fairings, and streamlined grill/hood/mirrors/bumpers, similar to SmartWay trucks today. The Bin IV aerodynamic category for high roof tractors builds upon the Bin III tractor body with additional aerodynamic treatments such as underbody airflow treatment, down exhaust, and lowered ride height, among other technologies. And finally, Bin V tractors incorporate advanced technologies which are currently in the prototype stage of development, such as advanced gap reduction, rearview cameras to replace mirrors, wheel system streamlining, and advanced body designs.

The agencies had proposed five aerodynamic bins for each tractor regulatory subcategory. The agencies received comments from ATA, EMA/TMA, and Volvo indicating that this approach was not consistent with the aerodynamics of low and mid roof tractors. High roof tractors are consistently paired with box trailer designs, and therefore manufacturers can design the tractor aerodynamics as a tractor-trailer unit and target specific areas like the gap between the tractor and trailer. In addition, the high roof tractors tend to spend more time at high speed operation which increases the impact of aerodynamics on fuel consumption and GHG emissions. On the other hand, low and mid roof tractors are designed to pull variable trailer loads and shapes. They may pull trailers such as flat bed, low boy, tankers, or bulk carriers. The loads on flat bed trailers can range from rectangular cartons with tarps, to a single roll of steel, to a front loader. Due to these variables, manufacturers do not design unique low and mid roof tractor aerodynamics but instead use derivatives from their high roof tractor designs. The aerodynamic improvements to the bumper, hood, windshield, mirrors, and doors are developed for the high roof tractor application and then carried over into the low and mid roof applications. As mentioned above, the types of designs that would move high roof tractors from a Bin III to Bins IV and V include features such as gap reducers and integral roof fairings which would not be appropriate on low and mid roof tractors. The agencies considered and largely agree with these comments and are therefore finalizing only two aerodynamic bins for low and mid roof tractors. The agencies are reducing the number of bins to reflect the actual range of aerodynamic technologies effective in low and mid roof tractor applications. Thus, the agencies are differentiating the aerodynamic performance for low and mid roof applications into two bins—conventional and aerodynamic. [74]

For high roof combination tractor compliance determination, a manufacturer would use the aerodynamic results determined through testing to establish the appropriate bin. The manufacturer would then input into GEM the Cd value specified for each bin as defined in Table II-7 and Table II-8. For example, if a manufacturer tests a Class 8 sleeper cab high roof tractor and the test produces a CdA value between 5.8 and 6.6, the manufacturer would assign this tractor to the Class 8 Sleeper Cab High Roof Bin III. The manufacturer would then use the Cd value identified for Bin III of 0.60 as the input to GEM.

The Cd values in Table II-7 and Table II-8 differ from proposal based on a change in the reference method (enhanced coastdown procedure) and additional testing conducted by EPA. Details of the test program and results are included in RIA Chapter 2.5.1.4.

Table II-7—Aerodynamic Input Definitions to GEM for High Roof Tractors Back to Top
Class 7 Class 8
Day cab Day cab Sleeper cab
High roof High roof High roof>
Aerodynamic Test Results (CdA in m2)      
Bin I ≥ 8.0 ≥ 8.0 ≥ 7.6
Bin II 7.1-7.9 7.1-7.9 6.7-7.5
Bin III 6.2-7.0 6.2-7.0 5.8-6.6
Bin IV 5.6-6.1 5.6-6.1 5.2-5.7
Bin V ≤ 5.5 ≤ 5.5 ≤ 5.1
Aerodynamic Input to GEM (Cd)      
Bin I 0.79 0.79 0.75
Bin II 0.72 0.72 0.68
Bin III 0.63 0.63 0.60
Bin IV 0.56 0.56 0.52
Bin V 0.51 0.51 0.47

The CdA values in Table II-8 are based on testing using the enhanced coastdown test procedures adopted for the final rulemaking, which includes aerodynamic assessment of the low and mid roof tractors without a trailer. The removal of the trailer significantly reduces the CdA value of mid roof tractors with tanker trailers because of the poor aerodynamic performance of the tanker trailer. The agencies developed the Cd input for each of the low and mid roof tractor bins to represent the Cd of the tractor, its frontal area, and the impact of the Cd value due to the trailer such that the GEM value is representative of a tractor-trailer combination, as it is for the high roof tractors.

Table II-8—Aerodynamic Input Definitions to GEM for Low and Mid Roof Tractors Back to Top
Class 7 Class 8
Day Cab Day Cab Sleeper Cab
Low Roof Mid Roof Low Roof Mid Roof Low Roof Mid Roof
Aerodynamic Test Results (CdA in m2)            
Bin I ≥ 5.1 ≥ 5.6 ≥ 5.1 ≥ 5.6 ≥ 5.1 ≥ 5.6
Bin II ≤ 5.0 ≤ 5.5 ≤ 5.0 ≤ 5.5 ≤ 5.0 ≤ 5.5
Aerodynamic Input to GEM (Cd)            
Bin I 0.77 0.87 0.77 0.87 0.77 0.87
Bin II 0.71 0.82 0.71 0.82 0.71 0.82

(d) Tire Rolling Resistance Assessment

NHTSA and EPA are finalizing as proposed that the tractor's tire rolling resistance input to the GEM be determined by either the tire manufacturer or tractor manufacturer using the test method adopted by the International Organization for Standardization, ISO 28580:2009. [75] The agencies believe the ISO test procedure is appropriate for this program because the procedure is the same one used by NHTSA in its fuel efficiency tire labeling program [76] and is consistent with the testing direction being taken by the tire industry both in the United States and Europe. The rolling resistance from this test would be used to specify the rolling resistance of each tire on the steer and drive axle of the tractor. The results would be expressed as a rolling resistance coefficient (CRR) and measured as kilogram per metric ton (kg/metric ton). The agencies are finalizing as proposed that three tire samples within each tire model be tested three times each to account for some of the production variability and the average of the nine tests would be the rolling resistance coefficient for the tire. The GEM will use the steer and drive tire rolling resistance inputs and distribute 15 percent of the gross weight of the tractor and trailer to the steer axle, 42.5 percent to the drive axles, and 42.5 percent to the trailer axles. [77] The trailer tires' rolling resistance is prescribed by the agencies as part of the standardized trailer used for demonstrating compliance at 6 kg/metric ton, which was the average trailer tire rolling resistance measured during the SmartWay tire testing. [78]

EPA and NHTSA conducted additional evaluation testing on HD trucks tires used for tractors, and also for vocational vehicles. The agencies also received several comments on the suitability of low rolling resistance tires for various HD vehicle applications. The summary of the agencies' findings and a response to issues raised by commenters is presented in Section II.D(1)(a).

(e) Weight Reduction Assessment

The agencies proposed that the tractor standards reflect improved CO 2 emissions and fuel consumption performance of a 400 pound weight reduction in Class 7 and 8 tractors through the substitution of single wide tires and light-weight wheels for dual tires and steel wheels. This approach was taken since there is a large variation in the baseline weight among trucks that perform roughly similar functions with roughly similar configurations. Because of this, the only effective way to quantify the exact CO 2 and fuel consumption benefit of mass reduction using GEM is to estimate baseline weights for specific components that can be replaced with light weight components. If the weight reduction is specified for light weight versions of specific components, then both the baseline and weight differentials for these are readily quantifiable and well-understood. Lightweight wheels are commercially available as are single wide tires and thus data on the weight reductions attributable to these two approaches are readily available.

The agencies received comments on this approach from Volvo, ATA, MEMA, Navistar, American Chemistry Council, the Auto Policy Center, Iron and Steel Institute, Arvin Meritor, Aluminum Association, and environmental groups and NGOs. Volvo and ATA stated that not all fleets can use single wide tires and if this is the case the 400 pound weight reduction target cannot be met. Volvo stated that without the use of single wide drive tires, a 6x4 tractor will have a maximum weight reduction of 300 pounds if the customer selects all ten wheels to be outfitted with light weight aluminum wheels. A number of additional commenters—including American Chemistry Council, The Auto Policy Center, Iron and Steel Institute, Aluminum Association, Arvin Meritor, MEMA, Navistar, Volvo, and environmental and nonprofit groups—stated that manufacturers should be allowed to use additional light weight components in order to meet the tractor fuel consumption and CO 2 emissions standards. These groups stated that weight reductions should not be limited to wheels and tires. They asked that cab doors, cab sides and backs, cab underbodies, frame rails, cross members, clutch housings, transmission cases, axle differential carrier cases, brake drums, and other components be allowed to be replaced with light-weight versions. Materials suggested for substitution included aluminum, light-weight aluminum, high strength steel, and plastic composites. The American Iron and Steel Institute stated there are opportunities to reduce mass by replacing mild steel—which currently dominates the heavy-duty industry—with high strength steel.

In addition, The American Auto Policy Center asked that manufacturers be allowed to use materials other than aluminum and high strength steel to comply with the regulations. DTNA asked that weight reduction due to engine downsizing be allowed to receive credit. Volvo requested that weight reductions due to changes in axle configuration be credited. They used the example of a customer selecting a 4 X 2 over a 6 X 4 axle tractor. In this case, they assert there would be a 1,000 pound weight savings from removing an axle.

As proposed, many of the material substitutions could have been considered as innovative technologies for tractors and hence eligible for off cycle credits (so that the commenters overstated that these technologies were `disallowed'). Nonetheless in response to the above summarized comments, the agencies evaluated whether additional materials and components could be used directly for compliance with the tractor weight reduction through the primary program (i.e. be available as direct inputs to the GEM). The agencies reviewed comments and data received in response to the NPRM and additional studies cited by commenters. A summary of this review is provided in the following paragraphs.

TIAX, in their report to the NAS, cited information from Alcoa identifying several mass reduction opportunities from material substitution in the tractor cab components which were similar to the ones identified by the Aluminum Association in their comments to this rulemaking. [79] TIAX included studies submitted by Alcoa showing the potential to reduce the weight of a tractor-trailer combination by 3,500 to 4,500 pounds. [80] In addition, the U.S. Department of Energy has several projects underway to improve the freight efficiency of Class 8 trucks which provide relevant data: [81] DOE reviewed prospective lightweighting alternative materials and found that aluminum has a potential to reduce mass by 40 to 60 percent, which is in line with the estimates of mass reductions of various components provided by Alcoa, and by the Aluminum Association in their comments and as cited in the TIAX report. These combined studies, comments, and additional data provided information on specific components that could be replaced with aluminum components.

With regard to high strength steel, the Iron and Steel Institute found that the use of high strength steel and redesign can reduce the weight of light-duty trucks by 25 percent. [82] Approximately 10 percent of this reduction results from material substitution and 15 percent from vehicle re-design. While this study evaluated light-duty trucks, the agencies believe that a similar reduction could be achieved in heavy-duty trucks since the reductions from material substitution would likely be similar in heavy-trucks as in light-trucks. U.S. DOE, in the report noted above, identified opportunities to reduce mass by 10 percent through high strength steel. [83] This study was also for light-duty vehicles.

The agencies considered other materials such as plastic composites and magnesium substitutes but were not able to obtain weights for specific components made from these materials. We have therefore not included components made from these materials as possible substitutes in the primary program, but they may be considered through the innovative technology/off-cycle credits provision. We may consider including these materials as part of the primary compliance option in a subsequent regulation if data become available.

Based on this analysis, the agencies developed an expanded list of weight reduction opportunities for the final rulemaking that may be reflected in the GEM, as listed in Table II-9. The list includes additional components, but not materials, from those proposed. For high strength steel, the weight reduction value is equal to 10 percent of the presumed baseline component weight, as the agencies used a conservative value based on the DOE report. We recognize that there may be additional potential for weight reduction in new high strength steel components which combine the reduction due to the material substitution along with improvements in redesign, as evidenced by the studies done for light-duty vehicles. In the development of the high strength steel component weights, we are only assuming a reduction from material substitution and no weight reduction from redesign, since we do not have any data specific to redesign of heavy-duty components nor do we have a regulatory mechanism to differentiate between material substitution and improved design. We are finalizing for wheels that both aluminum and light weight aluminum are eligible to be used as light-weight materials. Aluminum, but not light-weight aluminum, can be used as a light-weight material for other components. The reason for this is that data were available for light weight aluminum for wheels but were not available for other components.

The agencies received comments on the proposal from the American Chemistry Council highlighting the role of plastics and composites in heavy-duty vehicles. As they stated, composites can be low density while having high strength and are currently used in applications such as oil pans and buses. The DOE mass reduction program demonstrated for heavy vehicles proof of concept designs for hybrid composite doors with an overall mass savings of 40 percent; 30 percent mass reduction of a hood system with carbon fiber sheet molding compound; 50 percent mass reduction from composite tie rods, trailing arms, and axles; and superplastically formed aluminum body panels. [84] While the agencies recognize these opportunities, we do not believe the technologies have advanced far enough to quantify the benefits of these materials because they are very dependent on the actual composite material. The agencies may consider such lightweighting opportunities in future actions, but are not including them as part of this primary program. Manufacturers which opt to pursue composite and plastic material substitutions may seek credits through the innovative technology provisions.

With regard to Volvo's request that manufacturers be allowed to receive credit for trucks with fewer axles, the agencies recognize that vehicle options exist today which have less mass than other options. However, we believe the decisions to add or subtract such components will be made based on the intended use of the vehicle and not based on a crediting for the mass difference in our compliance program. It is not our intention to create a tradeoff between the right vehicle to serve a need (e.g. one with more or fewer axles) and compliance with our final standards. Therefore, we are not including provisions to credit (or penalize) vehicle performance based on the subtraction (or addition) of specific vehicle components. Table II-9 provides weight reduction values for different components and materials.

Table II-9—Weight Reduction Values Back to Top
Weight reduction technology Weight reduction (lb per tire/wheel)
Single Wide Drive Tire with:
Steel Wheel 84
Aluminum Wheel 139
Light Weight Aluminum Wheel 147
Steer Tire or Dual Wide Drive Tire with:
High Strength Steel Wheel 8
Aluminum Wheel 21
Light Weight Aluminum Wheel 30
Weight reduction technologies Aluminum weight reduction (lb.) High strength steel weight reduction (lb.)
Door 20 6
Roof 60 18
Cab rear wall 49 16
Cab floor 56 18
Hood Support Structure 15 3
Fairing Support Structure 35 6
Instrument Panel Support Structure 5 1
Brake Drums—Drive (4) 140 11
Brake Drums—Non Drive (2) 60 8
Frame Rails 440 87
Crossmember—Cab 15 5
Crossmember—Suspension 25 6
Crossmember—Non Suspension (3) 15 5
Fifth Wheel 100 25
Radiator Support 20 6
Fuel Tank Support Structure 40 12
Steps 35 6
Bumper 33 10
Shackles 10 3
Front Axle 60 15
Suspension Brackets, Hangers 100 30
Transmission Case 50 12
Clutch Housing 40 10
Drive Axle Hubs (8) 160 4
Non Drive Front Hubs (2) 40 5
Driveshaft 20 5
Transmission/Clutch Shift Levers 20 4

EPA and NHTSA are specifying the baseline vehicle weight for each regulatory vehicle subcategory (including the tires, wheels, frame, and cab components) in the GEM in aggregate based on weight of vehicles used in EPA's aerodynamic test program, but allow manufacturers to specify the use of light-weight components. The GEM then quantifies the weight reductions based on the pre-determined weight of the baseline component minus the pre-determined weight of the component made from light-weight material. Manufacturers cannot specify the weight of the light-weight component themselves, only the material used in the substitute component. The agencies assume the baseline wheel and tire configuration contains dual tires with steel wheels, along with steel frame and cab components, because these represent the vast majority of new vehicle configurations today. The weight reduction due to replacement of components with light weight versions will be reflected partially in the payload tons and partially in reducing the overall weight of the vehicle run in the GEM. The specified payload in the GEM will be set to the prescribed payload plus one third of the weight reduction amount to recognize that approximately one third of the truck miles are travelled at maximum payload, as discussed below in the payload discussion. The other two thirds of the weight reduction will be subtracted from the overall vehicle weight prescribed in the GEM.

The agencies continue to believe that the 400 pound weight target is appropriate to use as a basis for setting the final combination tractor CO 2 emissions and fuel consumption standards. The agencies agree with the commenter that 400 pounds of weight reduction without the use of single wide tires may not be achievable for all tractor configurations. As noted, the agencies have extended the list of weight reduction components in order to provide the manufacturers with additional means to comply with the combination tractors and to further encourage reductions in vehicle weight. The agencies considered increasing the target value beyond 400 pounds given the additional reduction potential identified in the expanded technology list; however, lacking information on the capacity for the industry to change to these lightweight components across the board by the 2014 model year, we have decided to maintain the 400 pound target. The agencies intend to continue to study the potential for additional weight reductions in our future work considering a second phase of vehicle fuel efficiency and GHG regulations. In the context of the current rulemaking for HD fuel consumption and GHG standards, one would expect that reducing the weight of medium-duty trucks similarly would, if anything, have a positive impact on safety. However, given the large difference in weight between light-duty and medium-duty vehicles, and even larger difference between light-duty vehicles and heavy-duty vehicles with loads, the agencies believe that the impact of weight reductions of medium- and heavy-duty vehicles would not have a noticeable impact on safety for any of these classes of vehicles. [85]

(f) Extended Idle Reduction Technology Assessment

Extended idling from Class 8 heavy-duty long haul combination tractors contributes to significant CO 2 emissions and fuel consumption in the United States. The Federal Motor Carrier Safety Administration regulations require a certain amount of driver rest for a corresponding period of driving hours. [86] Extended idle occurs when Class 8 long haul drivers rest in the sleeper cab compartment during rest periods as drivers find it both convenient and less expensive to rest in the tractor cab itself than to pull off the road and find accommodations. [87] During this rest period a driver will idle the tractor engine in order to provide heating or cooling, or to run on-board appliances. In some cases the engine can idle in excess of 10 hours. During this period, the engine will consume approximately 0.8 gallons of fuel and emit over 8,000 grams of CO 2 per hour. An average tractor engine can consume 8 gallons of fuel and emit over 80,000 grams of CO 2 during overnight idling in such a case.

Idling reduction technologies (IRT) are available to allow for driver comfort while reducing fuel consumptions and CO 2 emissions. Auxiliary power units, fuel operated heaters, battery supplied air conditioning, and thermal storage systems are among the technologies available today. The agencies are adopting a provision for use of extended idle reduction technology as an input to the GEM for Class 8 sleeper cabs. As discussed further in Section III, if a manufacturer wishes to receive credit for using IRT to meet the standard, then an automatic main engine shutoff must be programmed and enabled, such that engine shutdown occurs after 5 minutes of idling, to help ensure the reductions are realized in-use. A discussion of the provisions the agencies are adopting for allowing an override of this automatic shutdown can be found in RIA Chapter 2. As with all of the technology inputs discussed in this section, the agencies are not mandating the use of idle reductions or idle shutdown, but rather allowing their use as one part of a suite of technologies feasible for reducing fuel consumption and meeting the final standards and using these technologies as the inputs to the GEM. The default value (5 g CO 2/ton-mile or 0.5 gal/1,000 ton-mile) for the use of automatic engine shutdown (AES) with idle reduction technologies was determined as the difference between a baseline main engine with idle fuel consumption of 0.8 gallons per hour that idles 1,800 hours and travels 125,000 miles per year, and a diesel auxiliary power unit operating in lieu of main engine during those same idling hours. The agencies received various comments from ACEEE and MEMA regarding the assumptions used to derive the idle reduction value. ACEEE argued that the agencies should use a fuel consumption rate of 0.47 gallon/hour for main engine idling based on a paper written by Kahn. MEMA argued that the agencies should use a main engine idling fuel consumption rate of 0.87 gal/hr, which is the midpoint of a DOE calculator reporting fuel consumption rates from 0.64 to 1.15 gal/hr at idling conditions, and between 800 and 1200 rpm with the air conditioning on and off, respectively. The agencies respectfully disagree with the 0.47 gal/hr recommendation because the same paper by Kahn shows that while idling fuel consumption is 0.47 gal/hr on average at 600 rpm, CO 2 emissions increase by 25 percent with A/C on at 600 rpm, and increase by 165 percent between 600 rpm and 1,100 rpm with A/C on. [88] MEMA recommended using 2,500 hours per year for APU operation. They cited the SmartWay Web site which uses 2,400 hours per year (8 hours per day and 300 days per year). Also, they cited an Argonne study which assumed 7 hours per day and 303 days per year, which equals 2,121 hours per year. Lastly, they referred to the FMCSA 2010 driver guidelines which reduce the number of hours driven per day by one to two hours, which would lead to 2,650 to 2,900 hours per year. The agencies reviewed other studies to quantify idling operations, as discussed in greater detail in RIA Section 2.5.4.2, and believe that the entirety of the research does not support a change from the proposed calculation. Therefore, the agencies are finalizing the calculation as proposed. Additional details regarding the comments, calculations, and agency decisions are included in RIA Section 2.5.4.2.

The agencies are adopting a provision to allow manufacturers to provide an AES system which is active for only a portion of a vehicle's life. In this case, a discounted idle reduction value would be entered into GEM. A discussion of the calculation of a discounted IRT credit can be found in Section III. Additional details on the emission and fuel consumption reduction values are included in RIA Section 2.5.4.2.

(g) Vehicle Speed Limiters

The NPRM proposed to allow combination tractors that use vehicle speed limiters (VSL) to include the maximum governed speed value as an input to the GEM for purposes of determining compliance with the vehicle standards. The agencies also proposed not to assume the use of a mandatory vehicle speed limiter because of concerns about how to set a realistic application rate that avoids unintended consequences. See 75 FR at 74223. Governing the top speed of a vehicle can reduce fuel consumption and GHG emissions, because fuel consumption and CO 2 emissions increase proportionally to the square of vehicle speed. [89] Limiting the speed of a vehicle reduces the fuel consumed, which in turn reduces the amount of CO 2 emitted. The specific input to the GEM would be the maximum governed speed limit of the VSL that is programmed into the powertrain control module (PCM). The agencies stressed in the NPRM that in order to obtain a benefit in the GEM, a manufacturer must preset the limiter in such a way that the setting will not be “capable of being easily overridden by the fleet or the owner.” If the top speed could be easily overridden, the fuel consumption/CO 2 benefits of the VSL might not be realized, and the agencies did not want to allow the technology to be used for compliance if the technology could be disabled easily and the real world benefits not achieved.

Both the Center for Biological Diversity (CBD) and New York State Department of Transportation and Environmental Conservation commented that the application of speed limiters should be used to set the tractor standards. [90] CBD urged the agencies to reconsider the position and adopt a speed limitation technology. NY State commented that the technologies are cost effective, reduce emissions, and appear to be generally acceptable to the trucking industry. They continued to say that the vehicle speed limit could be set without compromising operational logistics.

Many commenters (Cummins, Daimler, EMA/TMA, ATA, AAPC, NADA) supported the use of VSLs as an input to the GEM, but requested clarification of what the specific requirements would be to ensure the VSL setting would not be capable of being easily overridden. Cummins and Daimler requested that the final rules explicitly allow vehicle manufacturers to access and adjust the VSL control feature for setting the maximum governed speed, arguing that the diverse needs of the commercial vehicle industry warrant flexibility in electronic control features, and that otherwise supply chain issues [91] may result from the use of VSLs. NADA and EMA/TMA also requested that VSLs have override features and be adjustable, citing various needs for flexibility by the fleets. EMA/TMA and ATA requested that VSLs be adjustable downward by fleets in order to obtain greater benefit in GEM, if company policies change or if a subsequent vehicle owner needs a different VSL setting. EMA/TMA stated that the agencies should prohibit tampering with VSLs, and both EMA and TRALA requested more information on how the agencies intended to address tampering with VSLs.

In addition to features governing the maximum vehicle speed, commenters requested adding other programmable flexibilities to mitigate potential drawbacks to VSLs. Cummins, DTNA, and EMA/TMA requested that a programmable “soft top” speed be added to PCMs which would allow a vehicle to exceed the speed limit setting governed by a VSL for a short period of time. A “soft top” feature could be used for a limited duration in order to maneuver and pass other on-road vehicles at speeds greater than that governed by the VSL. The commenters argued this was important for vehicle passing and safety-related situations where, without a soft top feature, it could be possible for speed limited trucks to obstruct other vehicles on the road and cause severe road congestion.

ATA and EMA/TMA also requested that manufacturers be allowed to program a mileage based expiration into the VSL control feature, in order to preserve the value of vehicles for second owners who may require operation at higher speeds. ATA further commented that manufacturers should be allowed to account for additional GEM input benefits if the speed governor is reprogrammed to a lower speed within the useful life of the vehicle.

After carefully considering the comments, the agencies have decided, for these final rules, to retain most of the elements in the proposal. Manufacturers will be allowed to implement a fixed maximum governed vehicle speed through a VSL feature and to use the maximum governed vehicle speed as an input to the GEM for certification. Also consistent with the proposal, the agencies are not premising the final standards on the use of VSLs. The comments received from stakeholders did not address the agencies' concerns discussed in the proposal, specifically the risk of requiring VSL in situations that are not appropriate from an efficiency perspective because it may lead to additional vehicle trips to deliver the same amount of freight. [92] The agencies continue to believe that we are not in a position to determine how many additional vehicles would benefit from the use of a VSL with a setting of less than 65 mph (a VSL with a speed set at or above 65 mph will show no CO 2 emissions or fuel consumption benefit on the drive cycles included in this program). The agencies further believe that manufacturers will not utilize VSLs unless it is in their interest to do so, so that these unintended consequences should not occur when manufacturers use VSLs as a compliance strategy. We will monitor the industry's use of VSL in this program and may consider using this technology in standard setting in the future.

The agencies have decided to adopt commenters' suggestions to allow adjustable lower limits that can be set and governed by VSLs independent of the one governing the maximum certified speed limit to provide the desired flexibility requested by the trucking industry. We believe that this flexibility would not decrease the anticipated fuel consumption or CO 2 benefits of VSLs because the adjustable limits would be lower values. Issues identified by the commenters including the ability to change delivery routes requiring lower governed speeds or when a fleet's business practices change resulting in a desire for greater fuel consumption savings are not in conflict with the purpose and benefit of VSLs. As such, the agencies have decided to allow a manufacturer to install features for its fleet customers to set their own lower adjustable limits below the maximum VSL specified by the agencies. However, the agencies have decided to not allow any additional benefit in the GEM to a manufacturer for allowing a lower governed speed in-use than the certified maximum limit for this first phase of the HD National Program because we can only be certain that the VSL will be at the maximum setting.

Both agencies also agree that manufacturers can provide a “soft top” and expiration features to be programmed into PCMs to provide additional flexibility for fleet owners and so that fleets who purchase used vehicles have the ability to have different VSL policies than the original owner of the vehicle. Although the agencies considered limiting the soft top maximum level due to safety and fuel consumption/GHG benefit concerns, we have decided to allow the soft top maximum level to be set to any level higher than the maximum speed governed by the VSL. This approach will provide drivers with the ability to better navigate through traffic. However, the agencies are requiring that manufacturers providing a soft top feature must design the system so it cannot be modified by the fleets and will not decrement the vehicle speed limit causing the vehicle to decelerate while the driver is operating a vehicle above the normal governed vehicle speed limit. For example, if a manufacturer designs a vehicle speed limiter that has a normal governed speed limiter setting of 62 mph, and a “soft top” speed limiter value of 65 mph, the algorithm shall not cause the vehicle speed to decrement causing the vehicle to decelerate while the driver is operating the vehicle at a speed greater that 62 mph (between 62 and 65 mph). The agencies are concerned that a forced deceleration when a driver is attempting to pass or maneuver could have an adverse impact on safety.

In using a soft top feature, a manufacturer will be required to provide to the agencies a functional description of the “soft top” control strategy including calibration values, the speed setting for both the hard limit and the soft top and the maximum time per day the control strategy could allow the vehicle to operate at the “soft top” speed limit at the time of certification. This information will be used to derive a factor to discount the VSL input used in the GEM to determine the fuel consumption and GHG emissions performance of the vehicle. The agencies also agree with comments that VSLs should be adjustable so as not to potentially limit a vehicle's resale value. However, manufacturers choosing the option to override the VSL after a specified number of miles would be required to discount the benefit of the VSL relative to the tractor's full lifetime miles. The VSL discount benefits for using soft-top and expiration features must be calculated using Equation II-1. [93] Additional details regarding the derivation of the discounted equation are included in RIA Chapter 2. The agencies are also requiring that any vehicle that has a “soft top” VSL to identify the use of the “soft top” VSL on the vehicle emissions label.

Equation II-1: Discounted Vehicle Speed Limiter Equation Back to Top

VSL input for GEM = Expiration Factor * [Soft Top Factor* Soft Top VSL + (1-Soft Top Factor) * VSL] + (1-Expiration Factor)*65 mph

The agencies will require that the VSL algorithm be designed to assure that over the useful life of the vehicle that the vehicle will not operate in the soft top mode for more miles than would be expected based on the values used in Equation 0-1, as specified by the expiration factor and the soft top factor. In addition, any time the cumulative percentage of operation in the soft top mode (based on miles) exceeds the maximum ratio that could occur at the full lifetime mileage, or at the expiration mileage if used, the algorithm must not allow the vehicle to exceed the VSL value. In this case, the soft top feature remain disabled until the vehicle mileage reaches a point where the ratio no longer meets this condition.

In response to the comments about how the agencies will evaluate tampering, NHTSA and EPA have added a number of requirements in these final rules relating to the VSL control feature. VSL control features should be designed so they cannot be easily overridden. Manufacturers must ensure that the governed speed limit programmed into the VSL must also be verifiable through on-board diagnostic scanning tools, and must provide a description of the coding to identify the governed maximum speed limit and the expiration mileage both at the time of the initial vehicle certification and in-use. The agencies believe both manufacturers and fleets should work toward maintaining the integrity of VSLs, and the agencies may conduct new-vehicle and in-use random audits to verify that inputs into GEM are accurate.

The agencies are aware that some fleets/owners make changes to vehicles, such as installing different diameter tires, changing the axle (final drive) ratio and transmission gearing, such that a vehicle could travel at speeds higher than the speed limited by its VSL. Vehicles subject to FMCSA requirements must be in compliance with 49 CFR 393.82. The requirements apply to speedometers and states as follows:

Each bus, truck, and truck-tractor must be equipped with a speedometer indicating vehicle speed in miles per hour and/or kilometers per hour. The speedometer must be accurate to within plus or minus 8 km/hr (5 mph) at a speed of 80 km/hr (50 mph).

To facilitate adjustments for component changes affecting vehicle speed, manufacturers should provide a fleet/owner with the means to do so unless the adjustments would affect the VSL setting or operation.

DTNA and ATA additionally requested that the agencies ensure that any VSL provisions adopted under the GHG emissions and fuel efficiency rules align with existing NHTSA standards. The agencies agree and note that there are no existing standards for a VSL outside of this current rulemaking activity. However, NHTSA has announced its intent to publish a proposal in 2012 for a VSL. [94] While both agencies have taken steps to avoid potential conflicts between the rulemaking being finalized today for fuel consumption and GHG emissions and the anticipated safety rulemaking, different conclusions may be reached in a safety-based rulemaking on VSLs, particularly in the approach to specifying soft top parameters and VSL expiration.

(h) Defined Vehicle Configurations in the GEM

As discussed above, the agencies are adopting methodologies that manufacturers will use to quantify the values input into the GEM for these factors affecting vehicle efficiency: Coefficient of Drag, Tire Rolling Resistance Coefficient, Weight Reduction, Vehicle Speed Limiter, and Extended Idle Reduction Technology. The other aspects of the vehicle configuration are fixed within the model and are not varied for the purpose of compliance. The defined inputs include the tractor-trailer combination curb weight, payload, engine characteristics, and drivetrain for each vehicle type, and others.

(i) Vehicle Drive Cycles

The GEM simulation model uses various inputs to characterize a vehicle's configuration (such as weight, aerodynamics, and rolling resistance) and predicts how the vehicle would behave on the road when it follows a driving cycle (vehicle speed versus time). As noted by the 2010 NAS Report, [95] the choice of a drive cycle used in compliance testing has significant consequences on the technology that will be employed to achieve a standard as well as the ability of the technology to achieve real world reductions in emissions and improvements in fuel consumption. Manufacturers naturally will design vehicles to ensure they satisfy regulatory standards. An ill-suited drive cycle for a regulatory category could encourage GHG emissions and fuel consumption technologies which satisfy the test but do not achieve the same benefits in use. For example, requiring all trucks to use a constant speed highway drive cycle will drive significant aerodynamic improvements. However, in the real world a combination tractor used for local delivery may spend little time on the highway, reducing the benefits achieved by this technology. In addition, the extra weight of the aerodynamic fairings will actually penalize the GHG and fuel consumption performance in urban driving and may reduce the freight carrying capability. The unique nature of the kinds of CO 2 emissions control and fuel consumption technology means that the same technology can be of benefit during some operation but cause a reduced benefit under other operation. [96] To maximize the GHG emissions and fuel consumption benefits and avoid unintended reductions in benefits, the drive cycle should focus on promoting technology that produces benefits during the primary operation modes of the application. Consequently, drive cycles used in GHG emissions and fuel consumption compliance testing should reasonably represent the primary actual use, notwithstanding that every vehicle has a different drive cycle in-use.

The agencies proposed a modified version of the California ARB Heavy Heavy-duty Truck 5 Mode Cycle [97] , using the basis of three of the cycles which best mirror Class 7 and 8 combination tractor driving patterns, based on information from EPA's MOVES model. [98] The key advantage of the California ARB 5 mode cycle is that it provides the flexibility to use several different modes and weight the modes to fit specific vehicle application usage patterns. For the proposal, EPA analyzed the five cycles and found that some modifications to the cycles were required to allow sufficient flexibility in weightings. The agencies proposed the use of the Transient mode, as defined by California ARB, because it broadly covers urban driving. The agencies also proposed altered versions of the High Speed Cruise and Low Speed Cruise modes which reflected only constant speed cycles at 65 mph and 55 mph respectively. In the NPRM, the agencies proposed to use three cycles which were the ARB transient cycle, a 55 mph steady state cruise, and a 65 mph steady state cruise.

The agencies received comment from NACAA recommending an increase in the high speed cruise cycle speed from the proposed value of 65 mph to 75 mph because trucks travel at higher speeds. The agencies analyzed the urban and rural interstate truck speed limits in each state to determine the national average truck speed limit. State interstate speed limits for trucks vary between 55 and 75 mph, depending on the state. [99] Based on this information, the national median truck speed limit is 65 mph. The agencies also analyzed the national average truck speed limit weighted by VMT for each state based on VMT data by state from the Federal Highway Administration as described in RIA Section 3.4.2. Based on this information, the national average VMT-weighted truck speed limit is 63 mph. The agencies continue to believe that the appropriate high speed cruise speed should be set at the national average truck speed limit to appropriately balance the evaluation of technologies such as aerodynamics, but not overstate the benefits of these technologies. Therefore, the agencies are adopting as proposed a speed of 65 mph for the high speed cruise cycle.

The agencies also received comments from Allison which disagreed with proposed drive cycles for combination tractors because the cycles did not account for external factors such as grades, wind, traffic condition, etc. Allison also believes that the acceleration rates are too low. The agencies recognize that the proposed drive cycles do not incorporate the external factors described by Allison. Parallel to the approach used to evaluate light-duty vehicles, the drive cycles do not incorporate either grade or wind which can be difficult to simulate in chassis dynamometer cells. In the final rules, the agencies are defining an approach that manufacturers may take to evaluate their aerodynamic packages in a wind-averaged condition and use a modified Cd value in GEM. [100] The agencies are also adopting provisions for the innovative technology demonstration that allows for the use of on-road testing which includes grades for technologies whose benefits are reflected with grade. Lastly, the agencies' final drive cycles for highway operation contain a constant speed, as proposed. The acceleration and deceleration rates are only used to bring the vehicle to the cruising speed and the CO 2 emissions and fuel consumption from these portions of the drive cycle are not included in the composite emissions and fuel consumption results. The agencies did not include the speed dithering, which is representative of actual driving and traffic conditions, in the proposed constant speed portion of the cycles because the dithering does not provide any additional distinction between technologies but only added complexity to the cycle. The agencies believe this approach is still appropriate for the final action.

Allison referred the agencies to the Oak Ridge National Laboratory and SmartWay program to review the amount of time long-haul vehicles spend on the highway. They believe the steady state highway speeds are overestimated. Data provided by Allison indicates that day cabs spend only 14 percent of miles traveling at speeds greater than 60 mph. NHTSA and EPA recognize that there is a variation in the amount of miles day cabs travel under different operations. As described above, the agencies are adopting an approach where tractors which operate like vocational vehicles may be regulated as such in the HD program. Thus, these day cabs will have a drive cycle weighting representative of vocational vehicles with more weighting on the transient operation and less on the highway speed operation.

For proposal, EPA and NHTSA relied on the EPA MOVES analysis of Federal Highway Administration data to develop the mode weightings to characterize typical operations of heavy-duty trucks, per Table II-10 below. [101] A detailed discussion of drive cycles is included in RIA Chapter 3. [102] The agencies are adopting the proposed drive cycle weightings for combination tractors.

Table II-10—Drive Cycle Mode Weightings Back to Top
Transient 55 mph cruise 65 mph cruise
Day Cabs 19% 17% 64%
Sleeper Cabs 5% 9% 86%

(ii) Standardized Trailers

As proposed, NHTSA and EPA are adopting provisions so that the tractor performance in the GEM is judged assuming the tractor is pulling a standardized trailer. The agencies did not receive any adverse comments related to this approach. The agencies believe that an assessment of the tractor fuel consumption and CO 2 emissions should be conducted using a tractor-trailer combination. We believe this approach best reflects the impact of the overall weight of the tractor-trailer and the aerodynamic technologies in actual use, where tractors are designed and used with a trailer. The GEM will continue to use a predefined typical trailer in assessing overall performance. The high roof sleeper cabs are paired with a standard box trailer; the mid roof tractors are paired with a tanker trailer; and the low roof tractors are paired with a flat bed trailer.

(iii) Empty Weight and Payload

The total weight of the tractor-trailer combination is the sum of the tractor curb weight, the trailer curb weight, and the payload. The total weight of a vehicle is important because it in part determines the impact of technologies, such as rolling resistance, on GHG emissions and fuel consumption. In this final action, the agencies are specifying each of these aspects of the vehicle, as proposed.

In use, trucks operate at different weights at different times during their operations. The greatest freight transport efficiency (the amount of fuel required to move a ton of payload) would be achieved by operating trucks at the maximum load for which they are designed all of the time. However, logistics such as delivery demands which require that trucks travel without full loads, the density of payload, and the availability of full loads of freight limit the ability of trucks to operate at their highest efficiency all the time. M.J. Bradley analyzed the Truck Inventory and Use Survey and found that approximately 9 percent of combination tractor miles travelled empty, 61 percent are “cubed-out” (the trailer is full before the weight limit is reached), and 30 percent are “weighed out” (operating weight equal 80,000 pounds which is the gross vehicle weight limit on the Federal Interstate Highway System or greater than 80,000 pounds for vehicles traveling on roads outside of the interstate system). [103]

As described above, the amount of payload that a tractor can carry depends on the category (or GVWR and GCWR) of the vehicle. For example, a typical Class 7 tractor can carry less payload than a Class 8 tractor. For proposal, the agencies used the Federal Highway Administration Truck Payload Equivalent Factors using Vehicle Inventory and Use Survey (VIUS) and Vehicle Travel Information System data to determine the proposed payloads. FHWA's results found that the average payload of a Class 8 vehicle ranged from 36,247 to 40,089 pounds, depending on the average distance travelled per day. [104] The same results found that Class 7 vehicles carried between 18,674 and 34,210 pounds of payload also depending on average distance travelled per day. Based on this data, the agencies proposed to prescribe a fixed payload of 25,000 pounds for Class 7 tractors and 38,000 pounds for Class 8 tractors for their respective test procedures. The agencies proposed a common payload for Class 8 day cabs and sleeper cabs as predefined GEM input because the data available do not distinguish based on type of Class 8 tractor. These payload values represent a heavily loaded trailer, but not maximum GVWR, since as described above the majority of tractors “cube-out” rather than “weigh-out.”

The agencies developed the proposed tractor curb weight inputs from actual tractor weights measured in two of EPA's test programs and based on information from the manufacturers. The proposed trailer curb weight inputs were derived from actual trailer weight measurements conducted by EPA and weight data provided to ICF International by the trailer manufacturers. [105]

The agencies received comments from UMTRI and ATA regarding the values assumed for the combination tractor weights. UMTRI recommended using 80,000 pounds for the total weight for tractor-trailer combinations. ATA based on their analysis of the Federal Highway Administration's Long Term Pavement Database, recommended 5,000 to 10,000 pound payload for Class 7 tractors and 25,000 to 30,000 pounds for Class 8 tractors. ATA also determined from the same database that 20 percent of tractor miles are empty, 67 percent cube-out, and 13 percent weigh-out. The agencies are adopting the proposed tractor-trailer weights because we do not have strong evidence to select other values and because changing the assumed values would not change the impact on GHG emissions or fuel consumption of the technologies included in this phase of the HD program (the relative stringency of the standards and the projected emission reductions do not change with assumed payload). NHTSA and EPA intend to continue evaluating additional sources of weight information in future phases of the program.

Details of the final individual weight inputs by regulatory category, as shown in Table II-11, are included in RIA Chapter 3.

Table II-11—Final Combination Tractor Weights Back to Top
Model type Regulatory subcategory Tractor tare weight (lbs) Trailer weight (lbs) Payload (lbs) Total weight (lbs)
Class 8 Sleeper Cab High Roof 19,000 13,500 38,000 70,500
Class 8 Sleeper Cab Mid Roof 18,750 10,000 38,000 66,750
Class 8 Sleeper Cab Low Roof 18,500 10,500 38,000 67,000
Class 8 Day Cab High Roof 17,500 13,500 38,000 69,000
Class 8 Day Cab Mid Roof 17,100 10,000 38,000 65,100
Class 8 Day Cab Low Roof 17,000 10,500 38,000 65,500
Class 7 Day Cab High Roof 11,500 13,500 25,000 50,000
Class 7 Day Cab Mid Roof 11,100 10,000 25,000 46,100
Class 7 Day Cab Low Roof 11,000 10,500 25,000 46,500

(iv) Standardized Drivetrain

The agencies' assessment at proposal of the current vehicle configuration process at the truck dealer's level was that the truck companies provide tools to specify the proper drivetrain matched to the buyer's specific circumstances. These dealer tools allow a significant amount of customization for drive cycle and payload to provide the best specification for each individual customer. The agencies are not seeking to disrupt this process. Optimal drivetrain selection is dependent on the engine, drive cycle (including vehicle speed and road grade), and payload. Each combination of engine, drive cycle, and payload has a single optimal transmission and final drive ratio. The agencies received comments from ArvinMeritor and ICCT which suggested that the agencies incorporate the actual drivetrain configuration (axle configuration, driveline efficiency, and transmission) into the GEM. The agencies continue to believe, and therefore are adopting as proposed, that it is appropriate to specify the engine's fuel consumption map, drive cycle, and payload; therefore, it makes sense to also specify the drivetrain that matches.

(v) Engine Input to the GEM for Tractors

As proposed, the agencies are defining the engine characteristics used in the GEM, including the fuel consumption map which provides the fuel consumption at hundreds of engine speed and torque points. If the agencies did not standardize the fuel map, then a tractor that uses an engine with emissions and fuel consumption better than the standards would require fewer vehicle reductions than those technically feasible reductions reflected in the final standards. The agencies are finalizing two distinct fuel consumption maps for use in the GEM. The first fuel consumption map would be used in the GEM for the 2014 through 2016 model years and represents an average engine which meets EPA's final 2014 model year engine CO 2 emissions standards. The same fuel map would be used for NHTSA's voluntary standards in the 2014 and 2015 model years, as well as its mandatory program in the 2016 model year. A second fuel consumption map will be used beginning in the 2017 model year and represents an engine which meets the 2017 model year CO 2 emissions and fuel consumption standards and accounts for the increased stringency in the final MY 2017 standard. The agencies have modified the 2017 MY fuel map used in the GEM for the final rulemaking to address comments received. Details regarding this change can be found in RIA Chapter 4.4.4. Effectively there is no change in stringency of the tractor vehicle (not including the engine standards over the full rulemaking period). [106] These inputs are appropriate given the separate regulatory requirement that Class 7 and 8 combination tractor manufacturers use only certified engines.

(i) Heavy-Duty Engine Test Procedure for Engines Installed in Combination Tractors

The HD engine test procedure consists of two primary aspects—a duty cycle and a metric to evaluate the emissions and fuel consumption.

EPA proposed that the GHG emission standards for heavy-duty engines under the CAA would be expressed as g/bhp-hr while NHTSA's proposed fuel consumption standards under EISA, in turn, be represented as gal/100 bhp-hr. The NAS panel did not specifically discuss or recommend a metric to evaluate the fuel consumption of heavy-duty engines. However, as noted above they did recommend the use of a load-specific fuel consumption metric for the evaluation of vehicles. [107] An analogous metric for engines is the amount of fuel consumed per unit of work. The g/bhp-hr metric is also consistent with EPA's current standards for non-GHG emissions for these engines. The agencies did not receive any adverse comments related to the metrics for HD engines; therefore, we are adopting the metrics as proposed.

The agencies believe it is appropriate to set standards based on a single test procedure, either the Heavy-duty FTP or SET, depending on the primary expected use of the engine. This approach differs from EPA's criteria pollutant standards for engines which currently require that manufacturers demonstrate compliance over the transient FTP cycle; over the steady-state SET procedure; and during not-to-exceed testing. EPA created this multi-layered approach to criteria emissions control in response to engine designs that optimized operation for lowest fuel consumption at the expense of very high criteria emissions when operated off the regulatory cycle. EPA's use of multiple test procedures for criteria pollutants helps to ensure that manufacturers calibrate engine systems for compliance under all operating conditions. We are not concerned if manufacturers further calibrate engines off-cycle to give better in-use fuel consumption while maintaining compliance with the criteria emissions standards as such calibration is entirely consistent with the goals of our joint program. Further, we believe that setting GHG and fuel consumption standards based on both transient and steady-state operating conditions for all engines could lead to undesirable outcomes.

It is critical to set standards based on the most representative test cycles in order for performance in-use to obtain the intended (and feasible) air quality and fuel consumption benefits. Tractors spend the majority of their operation at steady state conditions, and will obtain in-use benefit of technologies such as turbocompounding and other waste heat recovery technologies during this kind of typical engine operation. Turbocompounding is a very effective approach to lower fuel consumption under steady driving conditions typified by combination tractor trailer operation and is well reflected in testing over the SET test procedure. However, when used in driving typified by transient operation as we expect for vocational vehicles and as is represented by the Heavy-duty FTP, turbocompounding shows very little benefit. Setting an emission standard based on the Heavy-duty FTP for engines intended for use in combination tractor trailers could lead manufacturers to not apply turbocompounding even though it can be a highly cost effective means to reduce GHG emissions and lower fuel consumption. (It is for this reason that turbocompounding is not part of the technology basis for MHD or HHD engines installed in vocational vehicles.)

The agencies proposed that engines installed in tractors demonstrate compliance with the CO 2 emissions and fuel consumption standards over the SET cycle. Commenters such as Cummins, Bosch, Daimler, and Honeywell supported the proposed approach. ACEEE recommended adopting a new test cycle, such as the World Harmonized Duty Cycle which was developed using newer data, to evaluate HD engines. Daimler also supported the WHDC for future phases of the program. The agencies continue to believe the important issues and technical work related to setting new criteria pollutant emissions standards appropriate for the World Harmonized Duty Cycle are significant and beyond the scope of this rulemaking. The SET cycle remains representative of typical driving cycles for combination tractors (and engines installed in them). Therefore, the agencies are adopting the SET cycle to evaluate CO 2 emissions and fuel consumption of HD engines installed in tractors, as proposed.

The current non-GHG emissions engine test procedures also require the development of regeneration emission rates and frequency factors to account for the emission changes during a regeneration event (40 CFR 86.004-28). EPA and NHTSA proposed not to include these emissions from the calculation of the compliance levels over the defined test procedures. Cummins and Daimler supported this approach and stated that sufficient incentives already exist for manufacturers to limit regeneration frequency. Conversely, Volvo opposed the omission of IRAF requirements for CO 2 emissions because emissions from regeneration can be a significant portion of the expected improvement and a significant variable between manufacturers

At proposal, we considered including regeneration in the estimate of fuel consumption and GHG emissions and decided not to do so for two reasons. See 75 FR at 74188. First, EPA's existing criteria emission regulations already provide a strong motivation to engine manufacturers to reduce the frequency and duration of infrequent regeneration events. The very stringent 2010 NO X emission standards cannot be met by engine designs that lead to frequent and extend regeneration events. Hence, we believe engine manufacturers are already reducing regeneration emissions to the greatest degree possible. In addition to believing that regenerations are already controlled to the extent technologically possible, we believe that attempting to include regeneration emissions in the standard setting could lead to an inadvertently lax emissions standard. In order to include regeneration and set appropriate standards, EPA and NHTSA would have needed to project the regeneration frequency and duration of future engine designs in the time frame of this program. Such a projection would be inherently difficult to make and quite likely would underestimate the progress engine manufacturers will make in reducing infrequent regenerations. If we underestimated that progress, we would effectively be setting a more lax set of standards than otherwise would be expected. Hence in setting a standard including regeneration emissions we faced the real possibility that we would achieve less effective CO 2 emissions control and fuel consumption reductions than we will achieve by not including regeneration emissions. Therefore, the agencies are finalizing an approach as proposed which does not include the regenerative emissions.

(j) Chassis-Based Test Procedure

In the proposal, the agencies considered proposing a chassis-based vehicle test to evaluate Class 7 and 8 tractors based on a laboratory test of the engine and vehicle together. A “chassis dynamometer test” for heavy-duty vehicles would be similar to the Federal Test Procedure used today for light-duty vehicles.

However, the agencies decided not to propose the use of a chassis test procedure to demonstrate compliance for tractor standards due to the significant technical hurdles to implementing such a program by the 2014 model year. The agencies recognize that such testing requires expensive, specialized equipment that is not yet widespread within the industry. The agencies have only identified approximately 11 heavy-duty chassis sites in the United States today and rapid installation of new facilities to comply with model year 2014 is not possible. [108]

In addition, and of equal if not greater importance, because of the enormous numbers of vehicle configurations that have an impact on fuel consumption, we do not believe that it would be reasonable to require testing of many combinations of tractor model configurations on a chassis dynamometer. The agencies evaluated the options available for one tractor model (provided as confidential business information from a truck manufacturer) and found that the company offered three cab configurations, six axle configurations, five front axles, 12 rear axles, 19 axle ratios, eight engines, 17 transmissions, and six tire sizes—where each of these options could impact the fuel consumption and CO 2 emissions of the tractor. Even using representative grouping of tractors for purposes of certification, this presents the potential for many different combinations that would need to be tested if a standard were adopted based on a chassis test procedure.

The agencies received comments from ACEEE and UCS supporting a full vehicle testing approach, but these commenters recognized the difficulties in doing this in the first phase of the HD program. The agencies maintain that the full vehicle testing on chassis dynamometers is not feasible in the timeframe of this rulemaking, although we believe such an approach may be appropriate in the future, if more testing facilities become available and if the agencies are able to address the complexity of tractor configurations issue described above.

(4) Summary of Flexibility and Credit Provisions for Tractors and Engine Used in These Tractors

EPA and NHTSA are finalizing four flexibility provisions specifically for heavy-duty tractor and engine manufacturers, as discussed in Section IV below. These are an averaging, banking and trading program for emissions and fuel consumption credits, as well as provisions for early credits, advanced technology credits, and credits for innovative vehicle or engine technologies which are not included as inputs to the GEM or are not demonstrated on the engine SET test cycle. With the exception of the advanced technology credits, credits generated under these provisions can only be used within the same averaging set which generated the credit (for example, credits generated by HD engines installed in tractors can only be used by HD engines). EPA is also adopting a N 2 O emission credit program, as described in Section IV below.

(5) Deferral of Standards for Tractor and Engine Manufacturing Companies That Are Small Businesses

EPA and NHTSA are not adopting greenhouse gas emissions and fuel consumption standards for small tractor or engine manufacturers meeting the Small Business Administration (SBA) size criteria of a small business as described in 13 CFR 121.201. [109] The agencies will instead consider appropriate GHG and fuel consumption standards for these entities as part of a future regulatory action. This includes both U.S.-based and foreign small volume heavy-duty tractor and engine manufacturers.

The agencies have identified two entities that fit the SBA size criterion of a small business. [110] The agencies estimate that these small entities comprise less than 0.5 percent of the total heavy-duty combination tractors in the United States based on Polk Registration Data from 2003 through 2007, [111] and therefore that the exemption will have a negligible impact on the GHG emissions and fuel consumption improvements from the final standards.

To ensure that the agencies are aware of which companies would be exempt, we are requiring that such entities submit a declaration to EPA and NHTSA containing a detailed written description of how that manufacturer qualifies as a small entity under the provisions of 13 CFR 121.201.

C. Heavy-Duty Pickup Trucks and Vans

The primary elements of the EPA and NHTSA programs for complete HD pickups and vans are presented in this section. These provisions also cover optional chassis certification of incomplete HD vehicles and of Class 4 and 5 vehicles, as discussed in detail in Section V.B(1)(e). Section II.C(1) explains the form of the CO 2 and fuel consumption standards, the numerical levels for those standards, and the approach to phasing in the standards over time. The measurement procedure for determining compliance is discussed in Section II.C(2), and the EPA and NHTSA compliance programs are discussed in Section II.C(3). Section II.C(4) discusses implementation flexibility provisions. Section II.E discusses additional standards and provisions for N 2 O and CH 4 emissions, for vehicle air conditioning leakage, and for ethanol-fueled and electric vehicles. HD pickup and van air conditioning efficiency is not being regulated, for reasons discussed in Section II.E.

(1) What are the levels and timing of HD pickup and van standards?

(a) Vehicle-Based Standards

About 90 percent of Class 2b and 3 vehicles are pickup trucks, passenger vans, and work vans that are sold by the original equipment manufacturers as complete vehicles, ready for use on the road. In addition, most of these complete HD pickups and vans are covered by CAA vehicle emissions standards for criteria pollutants today (i.e., they are chassis tested similar to light-duty), expressed in grams per mile. This distinguishes this category from other, larger heavy-duty vehicles that typically have only the engines covered by CAA engine emission standards, expressed in grams per brake horsepower-hour. As a result, Class 2b and 3 complete vehicles share much more in common with light-duty trucks than with other heavy-duty vehicles.

Three of these commonalities are especially significant: (1) Over 95 percent of the HD pickups and vans sold in the United States are produced by Ford, General Motors, and Chrysler—three companies with large light-duty vehicle and light-duty truck sales in the United States, (2) these companies typically base their HD pickup and van designs on higher sales volume light-duty truck platforms and technologies, often incorporating new light-duty truck design features into HD pickups and vans at their next design cycle, and (3) at this time most complete HD pickups and vans are certified to vehicle-based rather than engine-based EPA standards. There is also the potential for substantial GHG and fuel consumption reductions from vehicle design improvements beyond engine changes (such as through optimizing aerodynamics, weight, tires, and accessories), and the manufacturer is generally responsible for both engine and vehicle design. All of these factors together suggest that it is appropriate and reasonable to set standards for the vehicle as a whole, rather than to establish separate engine and vehicle GHG and fuel consumption standards, as is being done for the other heavy-duty categories. This approach for complete vehicles is consistent with Recommendation 8-1 of the NAS Report, which encourages the regulation of “the final stage vehicle manufacturers since they have the greatest control over the design of the vehicle and its major subsystems that affect fuel consumption.” There was consensus in the public comments supporting this approach.

(b) Work-Based Attributes

In setting heavy-duty vehicle standards it is important to take into account the great diversity of vehicle sizes, applications, and features. That diversity reflects the variety of functions performed by heavy-duty vehicles, and this in turn can affect the kind of technology that is available to control emissions and reduce fuel consumption, and its effectiveness. EPA has dealt with this diversity in the past by making weight-based distinctions where necessary, for example in setting HD vehicle standards that are different for vehicles above and below 10,000 lb GVWR, and in defining different standards and useful life requirements for light-, medium-, and heavy-heavy-duty engines. Where appropriate, distinctions based on fuel type have also been made, though with an overall goal of remaining fuel-neutral.

The joint EPA GHG and NHTSA fuel economy rules for light-duty vehicles accounted for vehicle diversity in that segment by basing standards on vehicle footprint (the wheelbase times the average track width). Passenger cars and light trucks with larger footprints are assigned numerically higher target levels for GHGs and numerically lower target levels for fuel economy in acknowledgement of the differences in technology as footprint gets larger, such that vehicles with larger footprints have an inherent tendency to burn more fuel and emit more GHGs per mile of travel. Using a footprint-based attribute to assign targets also avoids interfering with the ability of the market to offer a variety of products to maintain consumer choice.

In developing this rulemaking, the agencies emphasized creating a program structure that would achieve reductions in fuel consumption and GHGs based on how vehicles are used and on the work they perform in the real world, consistent with the NAS report recommendations to be mindful of HD vehicles' unique purposes. Despite the HD pickup and van similarities to light-duty vehicles, we believe that the past practice in EPA's heavy-duty program of using weight-based distinctions in dealing with the diversity of HD pickup and van products is more appropriate than using vehicle footprint. Work-based measures such as payload and towing capability are key among the things that characterize differences in the design of vehicles, as well as differences in how the vehicles will be used. Vehicles in this category have a wide range of payload and towing capacities. These work-based differences in design and in-use operation are the key factors in evaluating technological improvements for reducing CO 2 emissions and fuel consumption. Payload has a particularly important impact on the test results for HD pickup and van emissions and fuel consumption, because testing under existing EPA procedures for criteria pollutants is conducted with the vehicle loaded to half of its payload capacity (rather than to a flat 300 lb as in the light-duty program), and the correlation between test weight and fuel use is strong. [112]

Towing, on the other hand, does not directly factor into test weight as nothing is towed during the test. Hence only the higher curb weight caused by heavier truck components would play a role in affecting measured test results. However towing capacity can be a significant factor to consider because HD pickup truck towing capacities can be quite large, with a correspondingly large effect on design.

We note too that, from a purchaser perspective, payload and towing capability typically play a greater role than physical dimensions in influencing purchaser decisions on which heavy-duty vehicle to buy. For passenger vans, seating capacity is of course a major consideration, but this correlates closely with payload weight.

Although heavy-duty vehicles are traditionally classified by their GVWR, we do not believe that GVWR is the best weight-based attribute on which to base GHG and fuel consumption standards for this group of vehicles. GVWR is a function of not only payload capacity but of vehicle curb weight as well; in fact, it is the simple sum of the two. Allowing more GHG emissions from vehicles with higher curb weight tends to penalize lightweighted vehicles with comparable payload capabilities by making them meet more stringent standards than they would have had to meet without the weight reduction. The same would be true for another common weight-based measure, the gross vehicle combination weight, which adds the maximum combined towing and payload weight to the curb weight.

Similar concerns about using weight-based attributes that include vehicle curb weight were raised in the EPA/NHTSA proposal for light-duty GHG and fuel economy standards: “footprint-based standards provide an incentive to use advanced lightweight materials and structures that would be discouraged by weight-based standards”, and “there is less risk of `gaming' (artificial manipulation of the attribute(s) to achieve a more favorable target) by increasing footprint under footprint-based standards than by increasing vehicle mass under weight-based standards—it is relatively easy for a manufacturer to add enough weight to a vehicle to decrease its applicable fuel economy target a significant amount, as compared to increasing vehicle footprint” (74 FR 49685, September 28, 2009). The agencies believe that using payload and towing capacities as the work-based attributes avoids the above-mentioned disincentive for the use of lightweighting technology by taking vehicle curb weight out of the standards determination.

After taking these considerations into account, EPA and NHTSA proposed to set standards for HD pickups and vans based on the proposed “work factor” attribute that combines vehicle payload capacity and vehicle towing capacity, in pounds, with an additional fixed adjustment for four-wheel drive (4wd) vehicles. This adjustment accounts for the fact that 4wd, critical to enabling the many off-road heavy-duty work applications, adds roughly 500 lb to the vehicle weight. There was consensus in the public comments supporting this attribute, and the agencies are adopting it as proposed. Target GHG and fuel consumption standards will be determined for each vehicle with a unique work factor (analogous to a target for each discrete vehicle footprint in the light-duty vehicle rules). These targets will then be production weighted and summed to derive a manufacturer's annual fleet average standard for its heavy-duty pickups and vans. Widespread support for the proposed work factor-based approach to standards and fleet average approach to compliance was expressed in the comments we received.

To ensure consistency and help preclude gaming, we are finalizing the proposed provision that payload capacity be defined as GVWR minus curb weight, and towing capacity as GCWR minus GVWR. For purposes of determining the work factor, GCWR is defined according to the Society of Automotive Engineers (SAE) Recommended Practice J2807 APR2008, GVWR is defined consistent with EPA's criteria pollutants program, and curb weight is defined as in 40 CFR 86.1803-01. Based on analysis of how CO 2 emissions and fuel consumption correlate to work factor, we believe that a straight line correlation is appropriate across the spectrum of possible HD pickups and vans, and that vehicle distinctions such as Class 2b versus Class 3 need not be made in setting standards levels for these vehicles. [113] This approach was supported by commenters.

We note that payload/towing-dependent gram per mile and gallon per 100 mile standards for HD pickups and vans parallel the gram per ton-mile and gallon per 1,000 ton-mile standards being finalized for Class 7 and 8 combination tractors and for vocational vehicles. Both approaches account for the fact that more work is done, more fuel is burned, and more CO 2 is emitted in moving heavier loads than in moving lighter loads. Both of these load-based approaches avoid penalizing vehicle designers wishing to reduce GHG emissions and fuel consumption by reducing the weight of their trucks. However, the sizeable diversity in HD work truck and van applications, which go well beyond simply transporting freight, and the fact that the curb weights of these vehicles are on the order of their payload capacities, suggest that setting simple gram/ton-mile and gallon/ton-mile standards for them is not appropriate. Even so, we believe that our setting of payload-based standards for HD pickups and vans is consistent with the NAS Report's recommendation in favor of load-specific fuel consumption standards. Again, commenters agreed with this approach to setting HD pickup and van standards.

These attribute-based CO 2 and fuel consumption standards are meant to be relatively consistent from a stringency perspective. Vehicles across the entire range of the HD pickup and van segment have their respective target values for CO 2 emissions and fuel consumption, and therefore all HD pickups and vans will be affected by the standard. With this attribute-based standards approach, EPA and NHTSA believe there should be no significant effect on the relative distribution of vehicles with differing capabilities in the fleet, which means that buyers should still be able to purchase the vehicle that meets their needs.

(c) Standards

The agencies are finalizing standards based on a technology analysis performed by EPA to determine the appropriate HD pickup and van standards. This analysis, described in detail in RIA Chapter 2, considered:

  • The level of technology that is incorporated in current new HD pickups and vans,
  • The available data on corresponding CO 2 emissions and fuel consumption for these vehicles,
  • Technologies that would reduce CO 2 emissions and fuel consumption and that are judged to be feasible and appropriate for these vehicles through the 2018 model year,
  • The effectiveness and cost of these technologies for HD pickup and vans,
  • Projections of future U.S. sales for HD pickup and vans, and
  • Forecasts of manufacturers' product redesign schedules.

Based on this analysis, EPA is finalizing the proposed CO 2 attribute-based target standards shown in Figure 0-2 and II-3, and NHTSA is finalizing the equivalent attribute-based fuel consumption target standards, also shown in Figure 0-2 and II-3, applicable in model year 2018. These figures also shows phase-in standards for model years before 2018, and their derivation is explained below, along with alternative implementation schedules to ensure equivalency between the EPA and NHTSA programs while meeting respective statutory obligations. Also, for reasons discussed below, the agencies proposed and are establishing separate targets for gasoline-fueled (and any other Otto-cycle) vehicles and diesel-fueled (and any other Diesel-cycle) vehicles. The targets will be used to determine the production-weighted fleet average standards that apply to the combined diesel and gasoline fleet of HD pickups and vans produced by a manufacturer in each model year.

Described mathematically, EPA's and NHTSA's target standards are defined by the followingformulae:

EPA CO 2 Target (g/mile) = [a × WF] + b

NHTSA Fuel Consumption Target (gallons/100 miles) = [c × WF] + d

Where:

WF = Work Factor = [0.75 × (Payload Capacity + xwd)] + [0.25 × Towing Capacity]

Payload Capacity = GVWR (lb) − Curb Weight (lb)

xwd = 500 lb if the vehicle is equipped with 4wd, otherwise equals 0 lb

Towing Capacity = GCWR (lb) − GVWR (lb)

Coefficients a, b, c, and d are taken from Table II-12 orTable II-13.

Table II-12—Coefficients for HD Pickup and Van Target Standards116 Back to Top
Model year a b c d
Diesel Vehicles        
2014 0.0478 368 0.000470 3.61
2015 0.0474 366 0.000466 3.60
2016 0.0460 354 0.000452 3.48
2017 0.0445 343 0.000437 3.37
2018 and later 0.0416 320 0.000409 3.14
Gasoline Vehicles        
2014 0.0482 371 0.000542 4.17
2015 0.0479 369 0.000539 4.15
2016 0.0469 362 0.000528 4.07
2017 0.0460 354 0.000518 3.98
2018 and later 0.0440 339 0.000495 3.81
Table II-13—Coefficients for NHTSA's First Alternative and EPA's Alternative HD Pickup and Van Target Standards Back to Top
Model year a b c d
Notes:
a NHTSA standards will be voluntary in 2014 and 2015.
Diesel Vehicles        
2014 a 0.0478 368 0.000470 3.61
2015 a 0.0474 366 0.000466 3.60
2016-2018 0.0440 339 0.000432 3.33
2019 and later 0.0416 320 0.000409 3.14
Gasoline Vehicles        
2014 a 0.0482 371 0.000542 4.17
2015 a 0.0479 369 0.000539 4.15
2016-2018 0.0456 352 0.000513 3.96
2019 and later 0.0440 339 0.000495 3.81

These targets are based on a set of vehicle, engine, and transmission technologies assessed by the agencies and determined to be feasible and appropriate for HD pickups and vans in the 2014-2018 timeframe. See Section III.B for a detailed analysis of these vehicle, engine and transmission technologies, including their feasibility, costs, and effectiveness in HD pickups and vans.

To calculate a manufacturer's HD pickup and van fleet average standard, the agencies are requiring that separate target curves be used for gasoline and diesel vehicles. The agencies estimate that in 2018 the target curves will achieve 15 and 10 percent reductions in CO 2 and fuel consumption for diesel and gasoline vehicles, respectively, relative to a common baseline for current (model year 2010) HD pickup trucks and vans. An additional two percent reduction in GHGs will be achieved by the direct air conditioning leakage standard in the EPA standards. These reductions are based on the agencies' assessment of the feasibility of incorporating technologies (which differ significantly for gasoline and diesel powertrains) in the 2014-2018 model years, and on the differences in relative efficiency in the current gasoline and diesel vehicles. The resulting reductions represent roughly equivalent stringency levels for gasoline and diesel vehicles, which is important in ensuring our program maintains product choices available to vehicle buyers.

In written comments on the proposal, Cummins objected to setting separate diesel and gasoline vehicle standards, on the basis that it increases the burden for diesel engine manufacturers more than for gasoline engine manufacturers, and thereby could shift market share away from diesels. EMA argued for fuel-neutrality based on historical precedent and the fact that GHGs emitted by one type of engine are no different than those emitted by another type of engine. We believe that both engine types have roughly equivalent redesign burdens as evidenced by the feasibility and cost analysis in RIA Chapter 2. Also, even though the emissions and fuel consumption reductions are expressed from a common diesel/gasoline baseline in these final rules, the actual starting base for diesels is at a lower level than for gasoline vehicles. Other industry commenters, including those with sizeable diesel sales, expressed general support for the standards. The agencies agree that standards that do not distinguish between fuel types are generally preferable where technological or market-based reasons do not strongly argue otherwise. These technological differences exist presently between gasoline and diesel engines for GHGs, as described above. The agencies emphasize, however, that they are not committed to perpetuating separate GHG standards for gasoline and diesel heavy-duty vehicles and engines, and expect to reexamine the need for separate gasoline/diesel standards in the next rulemaking.

Environmental groups and others commented that the proposed standards were not stringent enough, citing the heavy-duty vehicle NAS study finding that technologies such as hybridization are feasible. However, in the ambitious timeframe we are focusing on for these rules, targeting as it does technologies implementable in the HD pickup and van fleet starting in 2014 and phasing in with normal product redesign cycles through 2018, our assessment shows that the standards we are establishing are appropriate. More advanced technologies considered in the NAS report would be appropriate for consideration in future rulemaking activity. Additional conventional technologies identified by commenters as promising in light-duty applications and potentially useful for HD applications are discussed in RIA chapter 2.

The NHTSA fuel consumption target curves and the EPA GHG target curves are equivalent. The agencies established the target curves using the direct relationship between fuel consumption and CO 2 using conversion factors of 8,887 g CO 2/gallon for gasoline and 10,180 g CO 2/gallon for diesel fuel.

It is expected that measured performance values for CO 2 will generally be equivalent to fuel consumption. However, as explained below in Section 0, EPA is finalizing a provision for manufacturers to use CO 2 credits to help demonstrate compliance with N 2 O and CH 4 emissions standards, by expressing any N 2 O and CH 4 undercompliance in terms of their CO 2-equivalent and applying the needed CO 2 credits. For test families that do not use this compliance alternative, the measured performance values for CO 2 and fuel consumption will be equivalent because the same test runs and measurement data will be used to determine both values, and calculated fuel consumption will be based on the same conversion factors that are used to establish the relationship between the CO 2 and fuel consumption target curves (8,887 g CO 2/gallon for gasoline and 10,180 g CO 2/gallon for diesel fuel). For manufacturers that choose to use the EPA provision for CO 2 credit use in demonstrating N 2 O and CH 4 compliance, compliance with the CO 2 standard will not be directly equivalent to compliance with the NHTSA fuel consumption standard.

(d) Implementation Plan

(i) EPA Program Phase-In MY 2014-2018

EPA is finalizing the proposed provision that the GHG standards be phased in gradually over the 2014-2018 model years, with full implementation effective in the 2018 model year. Therefore, 100 percent of a manufacturer's vehicle fleet will need to meet a fleet-average standard that will become increasingly more stringent each year of the phase-in period. For both gasoline and diesel vehicles, this phase-in will be 15-20-40-60-100 percent of the model year 2018 stringency in model years 2014-2015-2016-2017-2018, respectively. These percentages reflect stringency increases from a baseline performance level for model year 2010, determined by the agencies based on EPA and manufacturer data. Because these vehicles are not currently regulated for GHG emissions, this phase-in takes the form of target line functions for gasoline and diesel vehicles that become increasingly stringent over the phase-in model years. These year-by-year functions have been derived in the same way as the 2018 function, by taking a percent reduction in CO 2 from a common unregulated baseline. For example, in 2014 the reduction for both diesel and gasoline vehicles will be 15 percent of the fully-phased-in reductions. Figures II-2 and II-3, and Table 0-12, reflect this phase-in approach.

EPA is also providing manufacturers with an optional alternative implementation schedule in model years 2016 through 2018, equivalent to NHTSA's first alternative for standards that do not change over these model years, described below. Under this option the phase-in will be 15-20-67-67-67-100 percent of the model year 2019 stringency in model years 2014-2015-2016-2017-2018-2019, respectively. Table 0-13, above, provides the coefficients “a” and “b” for this manufacturer's alternative. As explained below, this alternative will provide roughly equivalent overall CO 2 reductions and fuel consumption improvements as the 15-20-40-60-100 percent phase-in. In addition, as explained below, the stringency of this alternative was established by NHTSA such that a manufacturer with a stable production volume and mix over the model year 2016-2018 period could use Averaging, Banking and Trading to comply with either alternative and have a similar credit balance at the end of model year 2018.

Under the above-described alternatives, each manufacturer will need to demonstrate compliance with the applicable fleet average standard using that year's target function over all of its HD pickups and vans starting with its MY 2014 fleet of HD pickups and vans. No comments were received in support of an alternative approach that EPA requested comment on, involving phasing in an annually increasing percentage of each manufacturer's sales volume.

(ii) NHTSA Program Phase-In 2016 and Later

NHTSA is finalizing the proposed provision to allow manufacturers to select one of two fuel consumption standard alternatives for model years 2016 and later. Each manufacturer will select an alternative in its joint pre-model year report, discussed below, that is now required to be electronically submitted to the agencies; and, once selected, the alternative will apply for model years 2016 and later, and cannot be reversed. The first alternative will define a fuel consumption target line function for gasoline vehicles and a target line function for diesel vehicles that will not change for model years 2016 to 2018. The target line function coefficients are provided in Table II-13.

The second alternative will be equivalent to the EPA target line functions in each model year starting in 2016 and continuing afterwards. Stringency of fuel consumption standards will increase gradually for the 2016 and later model years. Relative to a model year 2010 unregulated baseline for both gasoline and diesel vehicles, stringency will be 40, 60, and 100 percent of the 2018 target line function in model years 2016, 2017, and 2018, respectively. The stringency of the target line functions in the first alternative for model years 2016-2017-2018-2019 is 67-67-67-100 percent, respectively, of the 2019 stringency in the second alternative. The stringency of the first alternative was established so that a manufacturer with a stable production volume and mix over the model year 2016-2018 period could use Averaging, Banking and Trading to comply with either alternative and have a similar credit balance at the end of model year 2018 under the EPA and NHTSA programs.

(iii) NHTSA Voluntary Standards Period

NHTSA is finalizing the proposed provision that manufacturers may voluntarily opt into the NHTSA HD pickup and van program in model years 2014 or 2015. If a manufacturer elects to opt in to the program, it must stay in the program for all the optional model years. Manufacturers that opt in become subject to NHTSA standards for all regulatory categories. To opt into the program, a manufacturer must declare its intent to opt in to the program in its Pre-Model Year Report. The agencies have finalized new requirements for manufacturers to provide all early model declarations as a part of the pre-model year reports. See regulatory text for 49 CFR 535.8 for information related to the Pre-Model Year Report. A manufacturer would begin tracking credits and debits beginning in the model year in which they opt into the program. The handling of credits and debits would be the same as for the mandatory program.

For manufacturers that opt into NHTSA's HD pickup and van fuel consumption program in 2014 or 2015, the stringency would increase gradually each model year. Relative to a model year 2010 unregulated baseline, for both gasoline and diesel vehicles, stringency would be 15-20 percent of the model year 2019 target line function stringency (under the NHTSA first alternative) and 15-20 percent of the model year 2018 target line function stringency (under the NHTSA second alternative) in model years 2014-2015, respectively. The corresponding absolute standards target levels are provided in Figure II-2 and II-3, and the accompanying equations.

(2) What are the HD pickup and van test cycles and procedures?

EPA and NHTSA are finalizing the proposed provision that HD pickup and van testing be conducted using the same heavy-duty chassis test procedures currently used by EPA for measuring criteria pollutant emissions from these vehicles, but with the addition of the highway fuel economy test cycle (HFET) currently required only for light-duty vehicle GHG emissions and fuel economy testing. Although the highway cycle driving pattern is identical to that of the light-duty test, other test parameters for running the HFET, such as test vehicle loaded weight, are identical to those used in running the current EPA Federal Test Procedure for complete heavy-duty vehicles.

The GHG and fuel consumption results from vehicle testing on the Light-duty FTP and the HFET will be weighted by 55 percent and 45 percent, respectively, and then averaged in calculating a combined cycle result. This result corresponds with the data used to develop the work factor-based CO 2 and fuel consumption standards, since the data on the baseline and technology efficiency was also developed in the context of these test procedures. The addition of the HFET and the 55/45 cycle weightings are the same as for the light-duty CO 2 and CAFE programs, as we believe the real world driving patterns for HD pickups and vans are not too unlike those of light-duty trucks, and we are not aware of data specifically on these patterns that would lead to a different choice of cycles and weightings, nor did any commenters provide such data. More importantly, we believe that the 55/45 weightings will provide for effective reductions of GHG emissions and fuel consumption from these vehicles, and that other weightings, even if they were to more precisely match real world patterns, are not likely to significantly improve the program results.

Another important parameter in ensuring a robust test program is vehicle test weight. Current EPA testing for HD pickup and van criteria pollutants is conducted with the vehicle loaded to its Adjusted Loaded Vehicle Weight (ALVW), that is, its curb weight plus ½ of the payload capacity. This is substantially more challenging than loading to the light-duty vehicle test condition of curb weight plus 300 pounds, but we believe that this loading for HD pickups and vans to ½ payload better fits their usage in the real world and will help ensure that technologies meeting the standards do in fact provide real world reductions. The choice is likewise consistent with use of an attribute based in considerable part on payload for the standard. We see no reason to set test load conditions differently for GHGs and fuel consumption than for criteria pollutants, and we are not aware of any new information (such as real world load patterns) since the ALVW was originally set this way that would support a change in test loading conditions, nor did any commenters provide such information. We are therefore using ALVW for test vehicle loading in GHG and fuel consumption testing.

Additional provisions for our final testing and compliance program are provided in Section V.B.

(3) How are the HD pickup and van standards structured?

EPA and NHTSA are finalizing the proposed fleet average standards for new HD pickups and vans, based on a manufacturer's new vehicle fleet makeup. In addition, EPA is finalizing proposed in-use standards that apply to the individual vehicles in this fleet over their useful lives. The compliance provisions for these fleet average and in-use standards for HD pickups and vans are largely based on the recently promulgated light-duty GHG and fuel economy program, as described in detail in the proposal.

(a) Fleet Average Standards

In the programs we are finalizing, each manufacturer will have a GHG standard and a fuel consumption standard unique to its new HD pickup and van fleet in each model year, depending on the load capacities of the vehicle models produced by that manufacturer, and on the U.S.-directed production volume of each of those models in that model year. Vehicle models with larger payload/towing capacities have individual targets at numerically higher CO 2 and fuel consumption levels than lower payload/towing vehicles, as discussed in Section II.C(1). The fleet average standard for a manufacturer is a production-weighted average of the work factor-based targets assigned to unique vehicle configurations within each model type produced by the manufacturer in a model year.

The fleet average standard with which the manufacturer must comply is based on its final production figures for the model year, and thus a final assessment of compliance will occur after production for the model year ends. Because compliance with the fleet average standards depends on actual test group production volumes, it is not possible to determine compliance at the time the manufacturer applies for and receives an EPA certificate of conformity for a test group. Instead, at certification the manufacturer will demonstrate a level of performance for vehicles in the test group, and make a good faith demonstration that its fleet, regrouped by unique vehicle configurations within each model type, is expected to comply with its fleet average standard when the model year is over. EPA will issue a certificate for the vehicles covered by the test group based on this demonstration, and will include a condition in the certificate that if the manufacturer does not comply with the fleet average, then production vehicles from that test group will be treated as not covered by the certificate to the extent needed to bring the manufacturer's fleet average into compliance. As in the light-duty program, additional “model type” testing will be conducted by the manufacturer over the course of the model year to supplement the initial test group data. The emissions and fuel consumption levels of the test vehicles will be used to calculate the production-weighted fleet averages for the manufacturer, after application of the appropriate deterioration factor to each result to obtain a full useful life value. See generally 75 FR 25470-25472.

EPA and NHTSA do not currently anticipate notable deterioration of CO 2 emissions and fuel consumption performance, and are therefore requiring that an assigned deterioration factor be applied at the time of certification: an additive assigned deterioration factor of zero, or a multiplicative factor of one will be used. EPA and NHTSA anticipate that the deterioration factor may be updated from time to time, as new data regarding emissions deterioration for CO 2 are obtained and analyzed. Additionally, EPA and NHTSA may consider technology-specific deterioration factors, should data indicate that certain control technologies deteriorate differently than others. See also 75 FR 25474.

(b) In-Use Standards

Section 202(a)(1) of the CAA specifies that EPA set emissions standards that are applicable for the useful life of the vehicle. The in-use standards that EPA is finalizing apply to individual vehicles. NHTSA is not adopting in-use standards because they are not required under EISA, and because it is not currently anticipated that there will be any notable deterioration of fuel consumption. For the EPA program, compliance with the in-use standard for individual vehicles and vehicle models will not impact compliance with the fleet average standard, which will be based on the production-weighted average of the new vehicles.

EPA is finalizing the proposed provision that the in-use standards for HD pickups and vans be established by adding an adjustment factor to the full useful life emissions and fuel consumption results used to calculate the fleet average. EPA is also finalizing the proposed provision that the useful life for these vehicles with respect to GHG emissions be set equal to their useful life for criteria pollutants: 11 years or 120,000 miles, whichever occurs first (40 CFR 86.1805-04(a)).

As discussed above, we are finalizing the proposed provision that certification test results obtained before and during the model year be used directly to calculate the fleet average emissions for assessing compliance with the fleet average standard. Therefore, this assessment and the fleet average standard itself do not take into account test-to-test variability and production variability that can affect measured in-use levels. For this reason, EPA is finalizing the proposed adjustment factor for the in-use standard to provide some margin for production and test-to- test variability that could result in differences between the initial emission test results used to calculate the fleet average and emission results obtained during subsequent in-use testing. EPA is finalizing the proposed provision that each model's in-use CO 2 standard be the model-specific level used in calculating the fleet average, plus 10 percent. This is the same as the approach taken for light-duty vehicle GHG in-use standards (See 75 FR 25473-25474). No adverse comments were received on this proposed provision.

As it does now for heavy-duty vehicle criteria pollutants, EPA will use a variety of mechanisms to conduct assessments of compliance with the in-use standards, including pre-production certification and in-use monitoring once vehicles enter customer service. The full useful life in-use standards apply to vehicles that have entered customer service. The same standards apply to vehicles used in pre-production and production line testing, except that deterioration factors are not applied.

(4) What HD pickup and van flexibility provisions are being established?

This program contains substantial flexibility in how manufacturers can choose to implement the EPA and NHTSA standards while preserving their timely benefits for the environment and energy security. Primary among these flexibilities are the gradual phase-in schedule, alternative compliance paths, and corporate fleet average approach which encompasses averaging, banking and trading described above. Additional flexibility provisions are described briefly here and in more detail in Section IV.

As explained in Section II.C(3), we are finalizing the proposed provision that, at the end of each model year, when production for the model year is complete, a manufacturer calculate its production-weighted fleet average CO 2 and fuel consumption. Under this approach, a manufacturer's HD pickup and van fleet that achieves a fleet average CO 2 or fuel consumption level better than its standard will be allowed to generate credits. Conversely, if the fleet average CO 2 or fuel consumption level does not meet its standard, the fleet would incur debits (also referred to as a shortfall).

A manufacturer whose fleet generates credits in a given model year will have several options for using those credits to offset emissions from other HD pickups and vans. These options include credit carry-back, credit carry-forward, and credit trading. These provisions exist in the light-duty 2012-2016 MY vehicle rule, and similar provisions are part of EPA's Tier 2 program for light-duty vehicle criteria pollutant emissions, as well as many other mobile source standards issued by EPA under the CAA. The manufacturer will be able to carry back credits to offset a deficit that had accrued in a prior model year and was subsequently carried over to the current model year, with a limitation on the carry-back of credits to three model years, consistent with the light-duty program. We are finalizing the proposed provision that, after satisfying any need to offset pre-existing deficits, a manufacturer may bank remaining credits for use in future years, with a limitation on the carry-forward of credits to five model years. We are also finalizing the proposed provision that manufacturers may certify their HD pickup and van fleet a year early, in MY 2013, to generate credits against the MY 2014 standards. This averaging, banking, and trading program for HD pickups and vans is discussed in more detail in Section IV.A. For reasons discussed in detail in that section, we are not finalizing any credit transferability to or from other credit programs or averaging sets.

Consistent with the President's May 21, 2010, directive to promote advanced technology vehicles and with the agencies' respective statutory authorities, we are adopting flexibility provisions that parallel similar provisions adopted in the light-duty program. These include credits for advance technology vehicles such as electric vehicles, and credits for innovative technologies that are shown by the manufacturer to provide GHG and fuel consumption reductions in real world driving, but not on the test cycle. See Section IV.B.

D. Class 2b-8 Vocational Vehicles

Heavy-duty vehicles serve a vast range of functions including service for urban delivery, refuse hauling, utility service, dump, concrete mixing, transit service, shuttle service, school bus, emergency, motor homes, [117] and tow trucks to name only a small subset of the full range of vehicles. The vehicles designed to serve these functions are as unique as the jobs they do. They are vastly different—one from the other—in size, shape and function. The agencies were unable to develop a specific vehicle definition based on the characteristics of these vehicles. Instead at proposal, we proposed to define that Class 2b-8 vocational vehicles as all heavy-duty vehicles which are not included in the Heavy-duty Pickup Truck and Van or the Class 7 and 8 Tractor categories. In effect, we said everything that is not a combination tractor or a pickup truck or van is a vocational vehicle. We are finalizing that definition as proposed reflecting the same challenges we faced at proposal regarding defining the full range of heavy-duty vehicles. As at proposal, recreational vehicles are included under EPA's standards but are not included under NHTSA's final standards. The agencies note that we are adding vocational tractors to the vocational vehicle category in the final rulemaking, as described above in Section II.B.

The agencies proposed that Class 4 pickup trucks although similar to Class 2b and 3 vehicles be included in the vocational vehicle category. Comments from EMA, Cummins, NTEA and Navistar supported the premise that Class 4 vehicles belong as part of the vocational vehicle program because they are specifically designed and engineered to meet vocational requirements. They stated that components such as transmissions, axles, frames, and tires differ from the similar pickup trucks and vans in the Class 2b and 3 market. We agree with commenters' arguments that there are a number of important differences between the Class 4 and Class 3 trucks it unreasonable to regulate Class 4 vehicles under the standards for heavy duty pickups and vans. As a result, we are keeping Class 4 vehicles in the vocational vehicle category, but are allowing the optional chassis certification of Class 4 and 5 vehicles. (See Section V.B(1)(e)).

As mentioned in Section I, vocational vehicles undergo a complex build process. Often an incomplete chassis is built by a chassis manufacturer with an engine purchased from an engine manufacturer and a transmission purchased from another manufacturer. A body manufacturer purchases an incomplete chassis which is then completed by attaching the appropriate features to the chassis.

The diversity in the vocational vehicle segment can be primarily attributed to the variety of vehicle bodies rather than to the chassis. For example, a body builder can build either a Class 6 bucket truck or a Class 6 delivery truck from the same Class 6 chassis. The aerodynamic difference between these two vehicles due to their bodies will lead to different baseline fuel consumption and GHG emissions. However, the baseline fuel consumption and emissions due to the components included in the common chassis (such as the engine, drivetrain, frame, and tires) will be the same between these two types of complete vehicles.

The agencies face difficulties in establishing the baseline CO 2 and fuel consumption performance for the wide variety of complete vocational vehicles because of the very large number of vehicle types and the need to conduct testing on each of the vehicle types to establish the baseline. To establish standards for a complete vocational vehicle, it would be necessary to assess the potential for fuel consumption and GHG emissions improvement for each of these vehicle types and to establish standards for each vehicle type. Because of the size and complexity of this task, the agencies judged it was not practical to regulate complete vocational vehicles for this first fuel consumption and GHG emissions program. To overcome the lack of baseline information from the different vehicle types and to still achieve improvements to fuel consumption and GHG emissions, the agencies proposed to set standards for the chassis manufacturers of vocational vehicles (but not the body builders) and the engine manufacturers. Chassis manufacturers represent a limited number of companies as compared to body builders, which are made up of a diverse set of companies that are typically small businesses. These companies would need to be regulated if whole vehicle standards were established.

Similar to combination tractors, the agencies proposed to set separate vehicle and engine standards for vocational vehicles. A number of comments were received on the proposal to regulate chassis and engine manufacturers. The agencies received comments from DTNA supporting the proposal to regulate the chassis manufacturer but not body manufacturers. While organizations like Cummins and ICCT expressed support for separate engine and vehicle standards, Navistar, Pew, and Volvo, in contrast, opposed separate engine and chassis standards, stating that separate engine standards disadvantages integrated truck/engine manufacturers and full vehicle standards should be required. Volvo asked that the standards include an alternative integrated standard as well as complete vehicle modeling and testing beginning in 2017. ACEEE and Sierra Club stated that the proposed standards and test procedures should move the agencies closer to full vehicle testing.

Although the agencies understand that full vehicle standards would allow integrated truck/engine manufacturers—such as electrified accessories and weight reduction—the agencies are finalizing separate standards for vocational vehicles that apply to chassis manufacturers and engine standards for engines installed in these vehicles that apply to engine manufacturers. The agencies continue to believe that it is not practical to regulate complete vocational vehicles for this first fuel consumption and GHG emissions program because of the size and complexity of the task associated with assessing the potential for fuel consumption and GHG emissions improvement for each of the myriad types of vocational vehicles. This issue is discussed further in comment responses found in sections 5 and 6.1.4 of the Response to Comment Document, as well as in the following section of the preamble. Thus, the agencies are finalizing a set of standards for the chassis manufacturers of vocational vehicles (but not the body builders) and for the manufacturers of HD engines used in vocational vehicles.

(1) What are the vocational vehicle and engine CO 2 and fuel consumption standards and their timing?

In the NPRM, the agencies proposed vehicle standards based on the agencies' assessment of the availability of low rolling resistance tires that could be applied generally to vocational vehicles across the entire category. The agencies considered the possibility of including other technologies in determining the proposed stringency of the vocational vehicle standards, such as aerodynamic improvements, but as discussed in the NPRM, tentatively concluded that such improvements would not be appropriate for basing vehicle standard stringency in this phase of the rulemaking. [118] For example, the aerodynamics of a recovery vehicle are impacted significantly by the equipment such as the arm located on the exterior of the truck. [119] The agencies found little opportunity to improve the aerodynamics of the equipment on the truck. The agencies also evaluated the aerodynamic opportunities discussed in the NAS report. The panel found that there was minimal fuel consumption reduction opportunity through aerodynamic technologies for bucket trucks, transit buses, and refuse trucks [120] primarily due to the low vehicle speed in normal operation. The panel did report that there are opportunities to reduce the fuel consumption of straight trucks by approximately 1 percent for trucks which operate at the average speed typical of a pickup and delivery truck (30 mph), although the opportunity is greater for vehicles that operate at higher speeds. [121]

The agencies received comments from the Motor Equipment Manufacturers Association, Eaton, NRDC, NESCAUM, NACAA, ACEEE, ICCT, Navistar, Arvin Meritor, the Union of Concerned Scientists and others that technologies such as idle reduction, advanced transmissions, advanced drivetrains, weight reduction, hybrid powertrains, and improved auxiliaries provide opportunities to reduce fuel consumption from vocational vehicles. Commenters asked that the agencies establish regulations that would reflect performance of these technologies and essentially force their utilization.

The agencies assessed these technologies and have concluded that they may have the potential to reduce fuel consumption and GHG emissions from at least certain vocational vehicles, but the agencies have not been able to estimate baseline fuel consumption and GHG emissions levels for each type of vocational vehicle and for each type of technology, given the wide variety of models and uses of vocational vehicles. For example, idle reduction technologies such as APUs and cabin heaters can reduce workday idling associated with vocational vehicles. However, characterizing idling activity for the vocational segment in order to quantify the benefits of idle reduction technology is complicated by the variety of duty cycles found in the sector. Idling in school buses, fire trucks, pickup trucks, delivery trucks, and other types of vocational vehicles varies significantly. Given the great variety of duty cycles and operating conditions of vocational vehicles and the timing of these rules, it is not feasible at this time to establish an accurate baseline for quantifying the expected improvements which could result from use of idle reduction technologies. Similarly, for advanced drivetrains and advanced transmissions determining a baseline configuration, or a set of baseline configurations, is extremely difficult given the variety of trucks in this segment. The agencies do not believe that we can legitimately base standard stringency on the use of technologies for which we cannot identify baseline configurations, because absent baseline emissions and baseline fuel consumption, the emissions reductions achieved from introduction of the technology cannot be quantified. For some technologies, such as weight reduction and improved auxiliaries—such as electrically driven power steering pumps and the vehicle's air conditioning system—the need to limit technologies to those under the control of the chassis manufacturer further restricted the agencies' options for predicating standard stringency on use of these technologies. For example, lightweight components that are under the control of chassis manufacturers are limited to a very few components such as frame rails. Considering the fuel efficiency and GHG emissions reduction benefits that will be achieved by finalizing these rules in the time frame proposed, rather than delaying in order to gain enough information to include additional technologies, the agencies have decided to finalize standards that do not assume the use of these technologies and will consider incorporating them in a later action applicable to later model years. Cf. Sierra Club v. EPA, 325 F. 3d 374, 380 (DC Cir. 2003) (in implementing a technology-forcing provision of the CAA, EPA reasonably adopted modest initial controls on an industry sector in order to better assess rules' effects in preparation for follow-up rulemaking).

As the program progresses and the agencies gather more information, we expect to reconsider whether vocational vehicle standards for MYs 2019 and beyond should be based on the use of additional technologies besides low rolling resistance tires.

EPA is adopting CO 2 standards and NHTSA is finalizing fuel consumption standards for manufacturers of chassis for new vocational vehicles and for manufacturers of heavy-duty engines installed in these vehicles. The final heavy-duty engine standards for CO 2 emissions and fuel consumption focus on potential technological improvements in fuel combustion and overall engine efficiency and those controls would achieve most of the emission reductions. Further reductions from the Class 2b-8 vocational vehicle itself are possible within the time frame of these final regulations. Therefore, the agencies are also finalizing separate standards for vocational vehicles that will focus on additional reductions that can be achieved through improvements in vehicle tires. The agencies' analyses, as discussed briefly below and in more detail later in this preamble and in the RIA Chapter 2, show that these final standards appear appropriate under each agency's respective statutory authorities. Together these standards are estimated to achieve reductions of up to 10 percent from most vocational vehicles.

EPA is also adopting standards to control N 2 O and CH 4 emissions from Class 2b-8 vocational vehicles through controlling these GHG emissions from the HD engines. The final heavy-duty engine standards for both N 2 O and CH 4 and details of the standard are included in the discussion in Section II.E.1.b and II.E.2.b. EPA neither proposed nor is adopting air conditioning leakage standards applying to vocational vehicle chassis manufacturers.

As discussed further below, the agencies are setting CO 2 and fuel consumption standards for the chassis based on tire rolling resistance improvements and for the engines based on engine technologies. The fuel consumption and GHG emissions impact of tire rolling resistance is impacted by the mass of the vehicle. However, the impact of mass on rolling resistance is relatively small so the agencies proposed to aggregate several vehicle weight categories under a single category for setting the standards. The agencies proposed to divide the vocational vehicle segment into three broad regulatory subcategories—Light Heavy-Duty (Class 2b through 5), Medium Heavy-Duty (Class 6 and 7), and Heavy Heavy-Duty (Class 8) which is consistent with the nomenclature used in the diesel engine classification. The agencies received comments supporting the division of vocational vehicles into three regulatory categories from DTNA. The agencies also received comments from Bosch, Clean Air Task Force, and National Solid Waste Management Association supporting a finer resolution of vocational vehicle subcategories. Their concerns include that the agencies' vehicle configuration in GEM is not representative of a particular vocational application, such as refuse trucks. Another recommendation was to divide the category by both GVWR and by operational characteristics. Upon further consideration, the agencies are finalizing as proposed three vocational vehicle subcategories because we believe this adequately balances simplicity while still obtaining reductions in this diverse segment. (As noted in section IV.A below, these three subcategories also denominate separate averaging sets for purposes of ABT.) Finer distinctions in regulatory subcategories would not change the technology basis for the standards or the reductions expected from the vocational vehicle category. As the agencies move towards future heavy-duty fuel consumption and GHG regulations for post-2017 model years, we intend to gather GHG and fuel consumption data for specific vocational applications which could be used to establish application-specific standards in the future.

The agencies received comments supporting the exclusion of recreational vehicles, emergency vehicles, school buses from the vocational vehicle standards. The commenters argued that these individual vehicle types were small contributors to overall GHG emissions and that tires meeting their particular performance needs might not be available by 2014. The agencies considered these comments and the agencies have met with a number of tire manufacturers to better understand their expectations for product availability for the 2014 model year. Based on our review of the information shared, we are convinced that tires with rolling resistance consistent with our final vehicle standards and meeting the full range of other performance characteristics desired in the vehicle market, including for RVs, emergency vehicles, and school buses, will be broadly available by the 2014 model year. [122] Absent regulations for the vast majority of vehicles in this segment, feasible cost-effective reductions available at reasonable cost in the 2014-2018 model years will be needlessly foregone. Therefore, the agencies have decided to finalize the vocational vehicle standards as proposed with recreational vehicles, emergency vehicles and school buses included in the vocational vehicle category. As RVs were not included by NHTSA for proposed regulation, they are not within the scope of the NPRM and are therefore excluded in NHTSA's portion of the final program. NHTSA will revisit this issue in the next rulemaking. In developing the final standards, the agencies have evaluated the current levels of emissions and fuel consumption, the kinds of technologies that could be utilized by manufacturers to reduce emissions and fuel consumption and the associated lead time, the associated costs for the industry, fuel savings for the consumer, and the magnitude of the CO 2 and fuel savings that may be achieved. After examining the possibility of vehicle improvements based on use of the technologies underlying the standards for Class 7 and 8 tractors, including improved aerodynamics, vehicle speed limiters, idle reduction technologies, tire rolling resistance, and weight reduction, as well as use of hybrid technologies, the agencies ultimately determined to base the final vehicle standards on performance of tires with superior rolling resistance. For standards for diesel engines installed in vocational vehicles, the agencies examined performance of engine friction reduction, aftertreatment optimization, air handling improvements, combustion optimization, turbocompounding, and waste heat recovery, ultimately deciding to base the final standards on the performance of all of the technologies except turbocompounding and waste heat recovery systems. The standards for gasoline engine installed in vocational vehicles are based on performance of technologies such as gasoline direct injection, friction reduction, and variable valve timing. The agencies' evaluation indicates that these technologies, as described in Section III.C, are available today in the heavy-duty tractor and light-duty vehicle markets, but have very low application rates in the vocational vehicle market. The agencies have analyzed the technical feasibility of achieving the CO 2 and fuel consumption standards, based on projections of what actions manufacturers would be expected to take to reduce emissions and fuel consumption to achieve the standards, and believe that the standards are cost-effective and technologically feasible and appropriate within the rulemaking time frame. EPA and NHTSA also present the estimated costs and benefits of the vocational vehicle standards in Section III.

(a) Vocational Vehicle Chassis Standards

In the NPRM, the agencies defined tire rolling resistance as a frictional loss of energy, associated mainly with the energy dissipated in the deformation of tires under load that influences fuel efficiency and CO 2 emissions. Tires with higher rolling resistance lose more energy in response to this deformation, thus using more fuel and producing more CO 2 emissions in operation, while tires with lower rolling resistance lose less energy, and save more fuel and CO 2 emissions in operation. Tire design characteristics (e.g., materials, construction, and tread design) influence durability, traction (both wet and dry grip), vehicle handling, ride comfort, and noise in addition to rolling resistance.

The agencies explained that a typical Low Rolling Resistance (LRR) tire's attributes, compared to a non-LRR tire, would include increased tire inflation pressure; material changes; and tire construction with less hysteresis, geometry changes (e.g., reduced height to width aspect ratios), and reduction in sidewall and tread deflection. When a manufacturer applies LRR tires to a vehicle, the manufacturer generally also makes changes to the vehicle's suspension tuning and/or suspension design in order to maintain vehicle handling and ride comfort.

The agencies also explained that while LRR tires can be applied to vehicles in all MD/HD classes, they may have special potential for improving fuel efficiency and reducing CO 2 emissions for vocational vehicles. According to an energy audit conducted by Argonne National Lab, tires are the second largest contributor to energy losses of vocational vehicles, after engines. [123] Given this finding, the agencies considered the availability of LRR tires for vocational applications by examining the population of tires available, and concluded that there appeared to be few LRR tires for vocational applications. The agencies suggested in the NPRM that this low number of LRR tires for vocational vehicles could be due in part to the fact that the competitive pressure to improve rolling resistance of vocational vehicle tires has been less than in the line haul tire market, given that line haul vehicles generally drive significantly more miles and therefore have significantly higher operating costs for fuel than vocational vehicles, and much greater incentive to improve fuel consumption. The small number of LRR tires for vocational vehicles may perhaps also be due in part to the fact that vocational vehicles generally operate more frequently on secondary roads, gravel roads and roads that have less frequent winter maintenance, which leads vocational vehicle buyers to value tire traction and durability more than rolling resistance. The agencies recognized that this provided an opportunity to improve fuel consumption and GHG emissions by creating a regulatory program that encourages improvements in tire rolling resistance for both line haul and vocational vehicles. The agencies proposed to base standards for all segments of HD vehicles on the use of LRR tires. The agencies estimated that a 10 percent reduction in average tire rolling resistance would be attainable between model years 2010 and 2014 based on the tire development achievements over the last several years in the line haul truck market. This reduction in tire rolling resistance would correlate to a two percent reduction in fuel consumption as modeled by the GEM. [124]

(i) Summary of Comments

The agencies received many comments on the subject of tire rolling resistance as applied to vocational vehicles. Comments included suggestions for alternative test procedures; whether LRR tires should be applied to certain types of vocational vehicles and whether certain vehicles should be exempted from the vocational vehicle standards if the standards are based on the ability to use LRR tires; the appropriateness of the proposed standards; and compliance issues (discussed below in Section II.D.2.b.

Regarding whether LRR tires should be applied to certain types of vocational vehicles, the agencies received many comments from stakeholders, such as Daimler Trucks North America, Fire Apparatus Manufacturers Association (FAMA), International Association of Fire Chiefs, National Ready Mix, National Solid Wastes Management Association (NSWMA), Spartan Motors, National Automobile Dealers Association, among others. There were comments regarding applicability of low rolling resistance tires to vocational vehicles based on LRR tire availability, suitability of the tires for the applications, fuel consumption and GHG emissions benefits and the appropriateness of standards. Many of these commenters focused particularly on the whether LRR tires would compromise the capability of emergency vehicles.

Regarding whether LRR tires are available in the market for certain vocational vehicles and whether the vocational vehicle standards were therefore appropriate and feasible, both Ford and AAPC stated that the proposed model-based requirement for Class 2b-8 vocational chassis appeared to require tires with rolling resistance values of approximately 8.0-8.1 kg/metric ton or better, and that limited data available for smaller diameter tires, such as light-truck (LT) tires used on many light heavy-duty trucks and vans, suggested that there exist few if any choices for tires that would comply. Given this concern about the availability of compliant tires, particularly in the case of tires smaller than 22.5″, during the proposed regulatory time frame, AAPC and Ford requested revisions to the requirement, or the modeling method, to establish different standards for vehicles that use different tire classes, with separate requirements for LT tires, 19.5″ tires, and 22.5″ tires. AAPC argued that standards should be set based on data collected on high volume in-use tires, and that they should be set at a level that ensures the availability of multiple compliant tires. CRR

(ii) Summary of Research Done Since the Notice of Proposed Rulemaking

Since the NPRM, the agencies have conducted additional research on tire rolling resistance for medium- and heavy-duty applications. This research involved direct discussions with tire suppliers, [125] assessment of the comments received, additional review of tire products available, and a more thorough review of tire use in the field. In addition, EPA has conducted tire rolling resistance testing to help inform the final rulemaking. [126]

The agencies discussed many aspects of low rolling resistance tire technologies and their application to vocational vehicles with tire suppliers since publication of the NPRM. Several tire suppliers indicated to the agencies that low rolling resistance tires are currently available for vocational applications that would enable compliance with the proposed vocational vehicle standards, such as delivery vehicles, refuse vehicles, and other vocations. However, these conversations also made the agencies aware that availability of low rolling resistance tires varies by supplier. Some suppliers stated they focused their company resources on areas of the medium- and heavy-duty vehicle spectrum where fleet operators would see the most fuel efficiency benefits for the application of low rolling resistance technologies; specifically the long-haul, on-highway applications that drive many miles and use large amounts of fuel. These suppliers stated that this choice was driven by the significant capital investment that would be needed to improve tire rolling resistance across the relatively large number of product offerings in the vocational vehicle segment, based on the wide range of tire sizes, load ratings, and speed ratings, compared to the much narrower range of offerings for long-haul applications. [127] Other suppliers stated that they have made conscious efforts to reduce the rolling resistance of all of their medium- and heavy-duty vehicle tire offerings, including vocational applications, in an effort to become leaders in this technology.

The agencies also discussed with tire suppliers the potential tire attribute tradeoffs that may be associated with incorporating designs that improve tire rolling resistance, given the driving patterns, environmental conditions, and on-road and off-road surface conditions that vocational vehicles are subjected to. Some vehicle manufacturer commenters had suggested that changes in tire tread block design that improve rolling resistance may adversely affect tire performance characteristics such as traction, resistance to tearing, and resistance to wear and damage from scrubbing on curbs and frequent tight radius turns that are important to customers for vocational vehicle performance. The suppliers agreed that providing tires unable to withstand these conditions or meet the vehicle application needs would adversely affect customer satisfaction and warranty expenses, and would have detrimental financial effects to their businesses. One supplier indicated that theoretically, tread-wear (tire life) could be compromised if suppliers choose to reduce the initial tire tread depth without any offsetting tire compound or design enhancements as the means to achieve rolling resistance reductions. That supplier argued that taking this approach could lead to more frequent tire replacements or re-treading of existing tire carcasses, and that the agencies should therefore take a total lifecycle view when evaluating the effects of driving rolling resistance reductions. That supplier also indicated that a correlation of a 20 percent reduction in rolling resistance achieved through tread depth reduction could lead to a 30 percent decrease in tread-life and 15 percent reduction in wet traction. The agencies note that when they inquired about potential `safety' related tradeoffs, such as traction (braking and handling) and tread wear when applying low rolling resistance technologies, tire suppliers which remain subject to safety standards regardless of this program, consistently responded that they would not produce a tire that compromises safety when fitted in its proper application.

In addition to the supplier discussions and evaluation of comments to the Notice of Proposed Rulemaking, EPA conducted a series of tire rolling resistance tests on medium- and heavy-duty vocational vehicle tires. The testing measured the CRR of tires representing 16 different vehicle applications for Class 4-8 vocational vehicles. The testing included approximately 5 samples each of both steer and drive tires for each application. The tests were conducted by two independent tire test labs, Standards Testing Lab (STL) and Smithers-Rapra (Smithers).

Overall, a total of 156 medium- and heavy-duty tires [128] were included in this testing, which was comprised of 88 tires covering various commercial vocational vehicle types, such as bucket trucks, school buses, city delivery vehicles, city transit buses and refuse haulers among others; 47 tires intended for application to tractors; and 21 tires classified as light-truck (LT) tires intended for Class 4 vocational vehicles such as delivery vans. In addition, approximately 20 of the tires tested were exchanged between the labs to assess inter-laboratory variability.

The test results for 88 commercial vocational vehicle tires (19.5″ and 22.5″ sizes) showed a test average CRR of 7.4 kg/metric ton, with results ranging from 5.1 to 9.8. To comply with the proposed vocational vehicle fuel consumption and GHG emissions standards using improved tire rolling resistance as the compliance strategy, a manufacturer would need to achieve an average tire CRR value of 8.1 kg/metric ton. [129] The measured average CRR of 7.4kg/metric ton is thus better than the average value that would be needed to meet vocational vehicle standards. Of those 173 tires tested, twenty tires had CRR values exceeding 8.1 kg/metric ton, two were at 8.1 kg/metric ton, and sixty-six tires were better than 8.1 kg/metric ton. Additional data analyses examining the tire data by tire size to determine the range and distribution of CRR values within each tire size showed each tire size generally had tires ranging from approximately 6.0 to 8.5 kg/metric ton, with a small number of tires in the 5.3-5.7 kg/metric ton range and a small number of tires in a range as high as 9.3-9.8 kg/ton. Review of the data showed that for each tire size and vehicle type, the majority of tires tested would enable compliance with vocational vehicle fuel consumption and GHG emission standards.

The test results for the 47 tires intended for tractor application showed an overall average of 6.9 kg/ton, the lowest overall average rolling resistance of the different tire applications tested. [130] This is consistent with what the agencies heard through comments and meetings with tire suppliers whose efforts have focused on tractor applications, particularly for long-haul applications, which yield the highest fuel efficiency benefits from LRR tire technology.

Finally, the 21 LT tires intended for Class 4 vocational vehicles were comprised of two sizes; LT225/75R16 and LT245/75R16 with 11 and 10 samples tested, respectively. Some auto manufacturers have indicated that CRR values for tires fitted to these Class 4 vehicles typically have a higher CRR values than tires found on commercial vocational vehicles because of the smaller diameter wheel size and the ISO testing protocol. [131] The test data showed the average CRR for LT225/75R16 tires was 9.1 kg/metric ton and the average for LT245/75R16 tires was 8.6 kg/metric ton. The range for the LT225/75R16 tires spanned 7.4 to 11.0 [132] and the range for the LT245/75R16 tires ranged from 6.6 to 9.8 kg/metric ton. Overall, the average for the tested LT tires was 8.9 kg/metric ton.

Analysis of the EPA test data for all vocational vehicles, including LT tires, shows the test average CRR is 7.7 kg/metric ton with a standard deviation of 1.2 kg/metric ton. Review of the data thus shows that for each tire size and vehicle type, there are many tires available that would enable compliance with the proposed standards for vocational vehicles and tractors except for LT tires for Class 4 vocational vehicles where test results show the majority of these tires have CRR worse than 8.1 kg/metric ton.

The agencies also reviewed the CRR data from the tires that were tested at both the STL and Smithers laboratories to assess inter-laboratory and test machine variability. The agencies conducted statistical analysis of the data to gain better understanding of lab-to-lab correlation and developed an adjustment factor for data measured at each of the test labs. When applied, this correction factor showed that for 77 of the 80 tires tested, the difference between the original CRR and a value corrected CRR was 0.01 kg/metric ton. The values for the remaining three tires were 0.03 kg/metric ton, 0.05 kg/metric ton and 0.07 kg/metric ton. Based on these results, the agencies believe the lab-to-lab variation for the STL and Smithers laboratories would have very small effect on measured CRR values. Further, in analyzing the data, the agencies considered both measurement variability and the value of the measurements relative to proposed standards. The agencies concluded that although laboratory-to-laboratory and test machine-to-test machine measurement variability exists, the level observed is not excessive relative to the distribution of absolute measured CRR performance values and relative to the proposed standards. Based on this, the agencies concluded that the test protocol is reasonable for this program, but are making some revisions to the vehicle standards.

The agencies also conducted a winter traction test of 28 tires to evaluate the impact of low rolling resistance designs on winter traction. The results of the study indicate that there was no statistical relationship between rolling resistance and snow traction. [133]

(iii) Summary of Final Rules

For vocational vehicles, the agencies intend to keep rolling resistance as an input to the GEM but with modifications to the proposed targets as a result of the testing completed by EPA since the NPRM and information from tire suppliers. The agencies continue to believe that LRR tires, which are an available, cost-effective, and appropriate technology with demonstrated fuel efficiency and GHG reduction benefits, are reasonable for all on-highway vehicles.

The agencies acknowledge there can be tradeoffs when designing a tire for reduced rolling resistance. These tradeoffs can include characteristics such as wear resistance, cost and scuff resistance. However, the agencies have continued to review this issue and do not believe that LRR tires as specified in the rules present safety issues. The agencies continue to believe that LRR tires, which are an available, cost-effective, and appropriate technology with demonstrated fuel efficiency and GHG reduction benefits, are reasonable for all on-highway vehicles. The final program also provides exemptions for vehicles meeting “low-speed” or “off-road” criteria, including application of speed restricted tires. Vocational vehicles that have speed restricted tires in order to accommodate particular applications may be exempted from the program under the off-road or low-speed exemption, described in greater detail below in Section II.D.(1)(a)(iv).

As just noted, the agencies conducted independent testing of current tires available to assist confirming the finalized rolling resistance standards. The tire test samples were selected from those currently available on the market and therefore have no known safety issues and meet all current requirements to allow availability in commerce; including wear, scuff resistance, braking, traction under wet or icy conditions, and other requirements. These tires included a wide array of sizes and designs intended for most all vocational applications, including those used for school buses, refuse haulers, emergency vehicles, concrete mixers, and recreational vehicles. As the test results revealed, there are a significant number of tires available that meet or do better than the rolling resistance targets for vocational vehicles; both light-truck (with an adjustment factor described later in this preamble section) and non-LT tire types, while meeting all applicable safety standards.

The agencies also recognize the extreme conditions fire apparatus equipment must navigate to enable firefighters to perform their duties. As described below, the final rules contain provisions to allow for exemption of specific off-road capable vocational vehicles from the fuel efficiency and greenhouse gas standards. Included in the exemption criteria are provisions for vehicles equipped with specific tire types that would be fit to a vehicle to meet extreme demands, including those vehicles designed for off-road capability.

As follow-up to the final rules and in support for development of a separate FMVSS rule, NHTSA plans to conduct additional performance-focused testing (beyond rolling resistance) for medium- and heavy-duty trucks. This testing is targeted for completion toward the end of this year. The agencies will review these performance data when available, in concert with any subsequent proposed rulemakings regarding fuel consumption and GHG emissions standards for medium- and heavy-duty vehicles.

For vocational vehicles, the rolling resistance of each tire will be measured using the ISO 28850 test method for drive tires and steer tires planned for fitment to the vehicle being certified. Once the test CRR values are obtained, a manufacturer will input the CRR values for the drive and steer tires separately into the GEM where, for vocational vehicles, the vehicle load is distributed equally over the steer and drive tires. Once entered, the amount of GHG reduction attributed to tire rolling resistance will be incorporated into the overall vehicle compliance value. The following table provides the revised target CRR values for vocational vehicles for 2014 and 2017 model years that are used to determine the vehicle standards.

Table II-14—Vocational Vehicle—Target CRR Values for GEM Input Back to Top
2014 MY 2017 MY
Tire Rolling Resistance (kg/metric ton) 7.7 kg/metric ton 7.7 kg/metric ton

These target values are being revised based on the significant availability of tires for vocational vehicles applications which have performance better than the originally proposed 8.1 kg/metric ton target. As just discussed, 63 of the 88 tires tested for vocational applications had CRR values better than the proposed target. The tires tested covered fitment to a wide range of vocational vehicle types and classes; thus agencies believe the original target value of 8.1 kg/metric ton was possibly too lenient after reviewing the testing data. Therefore, the agencies believe it is appropriate to reduce the proposed vehicle standard based on performance of a CRR target value of 7.7 kg/metric ton for non-LT tire type. As discussed previously, this value is the test average of all vocational tires tested (including LT) which takes a conservative approach over setting a target based on the average of only the non-LT vocational tires tested. For LT tires, based on both the test data and the comments from AAPC and Ford Motor Company, the agencies recognize the need to provide an adjustment. In lieu of having two sets of Light Heavy-Duty vocational vehicle standards, the agencies are finalizing an adjustment factor which applies to the CRR test results for LT tires. The agencies developed an adjustment factor dividing the overall vocational test average CRR of 7.7 by the LT vocational average of 8.9. This yields an adjustment factor of 0.87. For LT vocational vehicle tires, the measured CRR values will be multiplied by the 0.87 adjustment factor before entering the values in the GEM for compliance.

Based on the tire rolling resistance inputs noted above, EPA is finalizing the following CO 2 standards for the 2014 model year for the Class 2b through Class 8 vocational vehicle chassis, as shown in Table II-15. Similarly, NHTSA is finalizing the following fuel consumption standards for the 2016 model year, with voluntary standards beginning in the 2014 model year. For the EPA GHG program, the standard applies throughout the useful life of the vehicle. The agencies note that both the baseline performance and standards derived for the final rules slightly differ from the values derived for the NPRM. The first difference is due to the change in the target rolling resistance from 8.1 to 7.7 kg/metric ton based on the agencies' test results. Second, there are minor differences in the fuel consumption and CO 2 emissions due to the small modifications made to the GEM, as noted in RIA Chapter 4. Lastly, the final HHD vocational vehicle standard uses a revised payload assumption of 15,000 pounds instead of the 38,000 pounds used in the NPRM, as described in Section II.D.3.c.iii. As a result, the emission standards shown in Table II-15 for vocational vehicles have changed from the standards published in the NPRM. The changes for light heavy and medium heavy-duty vehicles are modest. The change for heavy heavy-duty vocational vehicles is larger, due to the difference in assumed payload.

As with the 2017 MY standards for Class 7 and 8 tractors, EPA and NHTSA are adopting more stringent vocational vehicle standards for the 2017 model year which reflect the CO 2 emissions reductions required through the 2017 model year engine standards. See also Section II.B.2 explaining the same approach for the standards for combination tractors. As explained in Section 0 below, engine performance is one of the inputs into the GEM compliance model that has a pre-defined (i.e. fixed) value established by the agencies, and that input will change in the 2017 MY to reflect the 2017 MY engine standards. The 2017 MY vocational vehicle standards are not premised on manufacturers installing additional vehicle technologies, and a vocational vehicle that complies with the standards in MY 2016 will also comply in MY 2017 with no vehicle (tire) changes. Thus, although chassis manufacturers will not be required to make further improvements in the 2017 MY to meet the standards, the standards will be more stringent to reflect the engine improvements required in that year. This is because in 2017 MY GEM vehicle modeling outputs (in grams per ton mile and gallons per 1,000 ton mile) will automatically decrease since engine efficiency will improve in that year.

Table II-15—Final Class 2 b-8 Vocational Vehicle CO 2 and Fuel Consumption Standards Back to Top
EPA CO 2 (gram/ton-mile) Standard Effective 2014 Model Year      
Light Heavy-Duty Class 2b-5 Medium Heavy-Duty Class 6-7 Heavy Heavy-Duty Class 8
CO 2 Emissions 388 234 226
NHTSA Fuel Consumption (gallon per 1,000 ton-mile) Standard Effective 2016 Model Year134      
Light Heavy-DutyClass 2b-5 Medium Heavy-Duty Class 6-7 Heavy Heavy-Duty Class 8
Fuel Consumption 38.1 23.0 22.2
EPA CO 2 (gram/ton-mile) Standard Effective 2017 Model Year      
Light Heavy-Duty Class 2b-5 Medium Heavy-Duty Class 6-7 Heavy Heavy-Duty Class 8
CO 2 Emissions 373 225 222
NHTSA Fuel Consumption (gallon per ton-mile) Standard Effective 2017 Model Year      
Light Heavy-Duty Class 2b-5 Medium Heavy-Duty Class 6-7 Heavy Heavy-Duty Class 8
Fuel Consumption 36.7 22.1 21.8

(iv) Off-Road and Low-Speed Vocational Vehicle Standards

Somevocational vehicles, because they are primarily designed for off-road use, may not be good candidates for low rolling resistance tires. These vehicles may travel on-road for very limited periods of time, such as in traveling on an urban road, or if they are off-loaded from another vehicle onto a road and then are driven off-road. The infrequent and limited exposure to on-road environments makes these vehicles suitable candidates for providing an exemption from the CO 2 emissions and fuel consumption standards for vocational vehicles (although the standards for HD engines used in vocational vehicles would still apply). [135] The agencies are also targeting other vehicles that travel at low speeds and that are meant to be used both on- and off-road. The application of certain technologies to these vehicles may not provide the same level of benefits as it would for pure on-road vehicles, and moreover, could even reduce the functionality of the vehicle. In this case, the agencies want to ensure that vehicle functionality is maintained to the maximum extent possible, while avoiding the possibility that achievable benefits are not realized because of the structure of the regulations. The sections below explain this issue in more detail as it applies to tractors and vocational vehicles.

The agencies explained in the NPRM that certain vocational vehicles have very limited on-road usage, and that although they would be defined as “motor vehicles” per 40 CFR 85.1703, the fact that they spend the most of their operations off-road might be reason for excluding them from the vocational vehicle standards. Vocational vehicles, such as those used on oil fields and construction sites, [136] experience very little benefit from LRR tires or from any other technologies to reduce GHG emissions and fuel consumption. The agencies proposed to allow a narrow range of these de facto off-road vehicles to be excluded from the proposed vocational vehicle standards if equipped with special off-road tires having lug type treads. The agencies stated in the NPRM that on/off road traction is the only tire performance parameter which trades off with TRR so significantly that tire manufacturers could be unable to develop tires meeting both a TRR standard while maintaining or improving the characteristic allowing them to perform off-road. See generally 75 FR at 74199-200. Therefore, the agencies proposed to exempt these vehicles from the standards while requiring them to use certified engines, which would provide fuel consumption and CO 2 emission reductions in all vocational applications. To ensure that these vehicles were in fact used chiefly off-road, the agencies proposed requirements that would allow exemption of a vehicle provided the vehicle and the tires were speed restricted. As mentioned, the agencies were aware that the majority of off road trucks primarily use off-road tires and are low speed vehicles as well. Based upon this understanding, the agencies specifically proposed that a vehicle must meet the following requirements to qualify for an exemption from vocational vehicle standards:

  • Tires which are lug tires or contain a speed rating of less than or equal to 60 mph; and
  • A vehicle speed limiter governed to 55 mph.

In response to the NPRM, EMA/TMA, Navistar and Volvo agreed with the proposal to exclude off-road vocational vehicles from the standards because these vehicles primarily operate off-road, but requested broadening the exclusion to cover other types of vocational vehicles. Several manufacturers (IAFC, FAMA, NTEA, NSWMA, AAPC, RMA, Navistar and DTNA) requested the exemption of specific vehicle types, such as on/off-road emergency vehicles, refuse vehicles, low speed transit buses or school buses, because their usage was viewed as being incompatible with LRR tires. Navistar opposed the application of the proposed regulations to school buses, arguing that LRR tires may impact the ride quality for children in school buses. However, Navistar also acknowledged that a significant portion of the national fleet of school buses already utilizes off-road tires designed with lug type tread patterns (e.g., Kentucky). IAFC, FAMA and NTEA commented that fire trucks and ambulances should also be exempted due to their part-time off-road use such as in responding to a wildland fire or hazardous materials incidents which would require operations on dirt and gravel roads, fields or other off-road environments. Commenters also contended that by requiring a 55-mph limitation, the proposed exemption would be impractical for emergency vehicles due to the need to respond quickly to life-threatening events. The refuse truck manufacturers and trade associations, NSWMA and AAPC, commented that the solid waste industry operates a variety of vocational vehicles that perform solely off-road at landfills. These comments also requested an exemption for certain refuse trucks (i.e., roll-off container trucks) that frequently go off-road at construction sites. Other commenters (FAMA, IAFC and Oshkosh) opposed compliance with the LRR standard for vocational vehicles for on/off road mixed service tires with aggressive or lug treads, stating that up to this point the industry has had very little interest in improving the LRR aspects of these tires or even to conducting testing to determine values for the coefficient of rolling resistance.

For the final rules, the agencies have considered the issues raised by commenters and have decided to adopt different criteria than proposed for exempting vocational vehicles and vocational tractors that primarily travel off-road. The agencies believe that the reasons for proposing the exemption are equally applicable to a wider class of vocational vehicles operating mostly off-road so that the proposals were either unsuitable for the industry or too restrictive to capture all the vehicles intended for the exemption. For example, the NPRM proposal, by using tire tread patterns and VSLs as the basis for qualifying vehicles for the exemption, was too restrictive because other non-lug type tread patterns exist in the market as well as other technologies which are equally capable of limiting the speed of the vehicle, as mentioned by Volvo. Therefore, the proposed exemption for off-road vocational vehicles will be replaced with new criteria based on the vehicle application, whether it operates at low speed and whether the vehicle has speed restricted tires. The exemption is in part based on existing industry standards established by NHTSA. [137] As such, any vocational vehicle including vocational tractors primarily used off-road or at low speeds must meet the following criteria to be exempt from GHG and fuel consumption vehicle standards:

  • Any vehicle primarily designed to perform work off-road such as in oil fields, forests, or construction sites and having permanently or temporarily affixed components designed to work in an off-road environment (i.e., hazardous material equipment or off-road drill equipment) or vehicles operating at low speeds making them unsuitable for normal highway operation; and meeting one or more of the following criteria:
  • Any vehicle equipped with an axle that has a gross axle weight rating (GAWR) of 29,000 pounds; or
  • Any truck or bus that has a speed attainable in 2 miles of not more than 33 mph; or
  • Any truck that has a speed attainable in 2 miles of not more than 45 mph, an unloaded vehicle weight that is not less than 95 percent of its gross vehicle weight rating (GVWR), and no capacity to carry occupants other than the driver and operating crew.

The agencies are also adopting in the final rules provisions to exempt any vocational vehicle that can operate in both on and off-road environments and has speed restricted tires rated at 55 mph or below. [138] The agencies' reasoning in adopting a speed restricted exemption for tires is that the majority of mixed service tires used for off-road use was identified as being restricted at 55 mph or less. [139] Also, as identified by FMVSS No. 119, speed restricted tires at a rating of 55 mph or less are incapable of meeting the same on-road performance standards as conventional tires. The agencies acknowledge that using a speed restriction criteria could allow certain vehicles to be exempted inappropriately (i.e., low speed city delivery tractors) but the agencies believe this is preferable to creating a situation where a segment of vehicles are precluded from performing their intended applications. Therefore, the final rules include an exemption for any mixed service (on and off-road) vocational vehicle equipped with off-road tires that are speed restricted at 55 mph or less.

Manufacturers choosing to exempt vehicles based on the above criteria will be required to provide a description of how they meet the qualifications for each vehicle family group in their end-of-the year and final year reports (see Section V).

A manufacturer having an off-road vehicle failing to meet the criteria under the agencies' off-road exemptions will be allowed to submit a petition describing how and why their vehicles should qualify for exclusion. The process of petitioning for an exemption is explained in § 1037.631 and § 535.8. For each request, the manufacturer will be required to describe why it believes an exemption is warranted and address the following factors which the agencies will consider in granting its petition:

  • The agencies provide an exemption based on off-road capability of the vehicle or if the vehicle is fitted with speed restricted tires. Which exemption does your vehicle qualify under; and
  • Are there any comparable tires that exist in the market to carry out the desired application both on and off road for the subject vehicle(s) of the petition which have LLR values that would enable compliance with the standard?

(b) Heavy-Duty Engine Standards for Engines Installed in Vocational Vehicles

EPA is finalizing GHG standards [140] and NHTSA is finalizing fuel consumption standards for new heavy-duty engines installed in vocational vehicles. The standards will vary depending on whether the engines are diesel or gasoline powered since emissions and fuel consumption profiles differ significantly depending on whether the engine is gasoline or diesel powered. The agencies' analyses, as discussed briefly below and in more detail later in this preamble and in the RIA Chapter 2, show that these standards are appropriate and feasible under each agency's respective statutory authorities.

The agencies have analyzed the feasibility of achieving the GHG and fuel consumption standards, based on projections of what actions manufacturers are expected to take to reduce emissions and fuel consumption. EPA and NHTSA also present the estimated costs and benefits of the heavy-duty engine standards in Section III below. In developing the final rules, the agencies have evaluated the kinds of technologies that could be utilized by engine manufacturers compared to a baseline engine, as well as the associated costs for the industry and fuel savings for the consumer and the magnitude of the GHG and fuel consumption savings that may be achieved.

EPA's existing criteria pollutant emissions regulations for heavy-duty highway engines establish four service classes (three for compression-ignition or diesel engines and one for spark ignition or gasoline engines) that represent the engine's intended and primary vehicle application, as shown in Table II-16 (40 CFR 1036.140 and NHTSA's 49 CFR 535.4). The agencies proposed to use the existing service classes to define the engine subcategories in this HD GHG emissions and fuel consumption program. The agencies did not receive any adverse comments to using this approach. Thus, the agencies are adopting the four engine subcategories for this final action.

Table II-16—Engine Regulatory Subcategories Back to Top
Engine category Intended application
Light Heavy-duty (LHD) Diesel Class 2b through Class 5 trucks (8,501 through 19,500 pounds GVWR).
Medium Heavy-duty (MHD) Diesel Class 6 and Class 7 trucks (19,501 through 33,000 pounds GVWR).
Heavy Heavy-duty (HHD) Diesel Class 8 trucks (33,001 pounds and greater GVWR.
Gasoline Incomplete vehicles less than 14,000 pounds GVWR and all vehicles (complete or incomplete) greater than 14,000 pounds GVWR.

(i) Diesel Engine Standards for Engines Installed in Vocational Vehicles

In the NPRM, the agencies proposed the following CO 2 and fuel consumption standards for HD diesel engines to be installed in vocational vehicles, as shown in Table II-17.

Table II-17—Vocational Diesel Engine Standards Over the Heavy-Duty FTP Cycle Back to Top
Model year Standard Light heavy-duty diesel Medium heavy-duty diesel Heavy heavy-duty diesel
2014-2016 CO 2 Standard (g/bhp-hr) 600 600 567
Voluntary Fuel Consumption Standard (gallon/100 bhp-hr) 5.89 5.89 5.57
2017 and Later CO 2 Standard (g/bhp-hr) 576 576 555
Fuel Consumption (gallon/100 bhp-hr) 5.66 5.66 5.45

The agencies explained in the NPRM that the standards were based on our assessment of the findings of the 2010 NAS report and other literature sources that there are technologies available to reduce fuel consumption in all these engines by this level in the final time frame in a cost-effective manner. Similar to the technology basis for HD engines used in combination tractors, these technologies include improved turbochargers, aftertreatment optimization, low temperature exhaust gas recirculation, and engine friction reductions.

The agencies proposed that the HD diesel engine CO 2 standards for vocational vehicles would become effective in MY 2014 for EPA, with more stringent CO 2 standards becoming effective in MY 2017, while NHTSA's fuel consumption standards would become effective in MY 2017, which would be both consistent with the EISA four-year minimum lead-time requirements and harmonized with EPA's timing for stringency increases. The agencies explained that the three-year timing, besides being required by EISA, made sense because EPA's heavy-duty highway engine program for criteria pollutants had begun to provide new emissions standards for the industry in three year increments, which had caused the heavy-duty engine and vehicle manufacturer product plans to fall largely into three year cycles reflecting this regulatory environment. [141] To further harmonize with EPA, NHTSA proposed voluntary fuel consumption standards for HD diesel engines for vocational vehicles in MYs 2014-2016, allowing manufacturers to opt into the voluntary standards in any of those model years. [142] Manufacturers opting into the program must declare by statement their intent to comply prior to or at the same time they submit their first application for a certificate of conformity. A manufacturer opting into the program would begin tracking credits and debits beginning in the model year in which they opt in. Both agencies proposed to allow manufacturers to generate and use credits to achieve compliance with the HD diesel engine standards for vocational vehicles, including averaging, banking, and trading (ABT), and deficit carry-forward.

The agencies proposed to require HD diesel engine manufacturers to achieve, on average, a three percent reduction in fuel consumption and CO 2 emissions for the 2014 standards over the baseline MY 2010 performance for the HHD diesel engines, and a five percent reduction for the LHD and MHD diesel engines. The standards for the LHD and MHD engine categories were proposed to be set at the same level because the agencies found that there is an overlap in the displacement of engines which are currently certified as LHDD or MHDD. The agencies developed the baseline 2010 model year CO 2 emissions from data provided to EPA by manufacturers during the non-GHG certification process. Analysis of CO 2 emissions from 2010 model year LHD and MHDD diesel engines showed little difference between LHD and MHD diesel engine baseline CO 2 performance in the 2010 model year, which overall averaged 630 g CO 2/bhp-hr (6.19 gal/100 bhp-hr). [143] Furthermore, the technologies available to reduce fuel consumption and CO 2 emissions from these two categories of engines are similar. The agencies considered combining these engine categories into a single category, but decided to maintain these two separate engine categories with the same standard level to respect the different useful life periods associated with each category.

For vocational engines certified on the FTP cycle, the agencies proposed to require a five percent reduction for HHD engines and nine percent for LHD and MHD engines. For LHD and MHD engines in 2017 MY, the nine percent reduction is based on the assumption that valvetrain friction reduction can be achieved in LHD and MHD engines in addition to turbo efficiency and accessory (water, oil, and fuel pump) improvements, improved EGR cooler, and other approaches being used for HHD engines.

Commenters who discussed the HD diesel engine standards generally did not differentiate between the standards for engines used in combination tractors and the engines used in vocational vehicles. As explained above in Section II.B.2.b, some commenters, such as EMA/TMA, Cummins, DTNA, and other manufacturers, supported the proposed standards, as long as the flexibilities proposed in the NPRM were finalized as proposed. Volvo argued that the standards are being phased in too quickly. Environmental groups and NGOs commented that the standards should be more stringent and reflect the potential for greater fuel consumption and CO 2 emissions reductions through the use of additional technologies outlined in the 2010 NAS study.

In response to those comments, the agencies refer back to our discussion in Section II.B.2.b. The agencies believe that the additional reductions may be achieved through the increased development of the technologies evaluated for the 2014 model year standard, but the agencies' analysis indicates that this type of advanced engine development will require a longer development time than MY 2014. The agencies are therefore providing additional lead time to allow for the introduction of this additional technology, and waiting until 2017 to increase stringency to levels reflecting application of turbocompounding. See Chapter 2 of the RIA for more details.

While it made sense to set standards at the same level for LHD and MHD diesel engines for vocational vehicles, the agencies found that it did not make sense to set HHD standards at the same level. Based on manufacturer-submitted CO 2 data for the non-GHG emissions certification process, the agencies found that the baseline for HHD diesel engines was much lower than for LHD/MHD diesel engines—584 g CO 2/bhp-hr (5.74 gal/100 bhp-hr) on average for HHD, compared to 630 g CO 2/bhp-hr (6.19 gal/100 bhp-hr) on average for LHD/MHD. [144] In addition to the differences in the baseline performance, the agencies believe that there may be some technologies available to reduce fuel consumption and CO 2 emissions that may be appropriate for the HHD diesel engines but not for the LHD/MHD diesel engines, such as turbocompounding. Therefore, the agencies are setting a different standard level for HHD diesel engines to be used in vocational vehicles. Additional discussion on technical feasibility is included in Section III below and in Chapter 2 of the RIA.

After consideration of the comments, EPA and NHTSA are adopting as proposed the CO 2 emission standards and fuel consumption standards for heavy-duty diesel engines installed in vocational vehicles are presented in Table II-17. Consistent with proposal, the first set of standards take effect with MY 2014 (mandatory standards for EPA, voluntary standards for NHTSA), and the second set take effect with MY 2017 (mandatory for both agencies).

Compliance with the standards for engines installed in vocational vehicles will be evaluated based on the composite HD FTP cycle. In the NPRM, the agencies proposed standards based on the Heavy-duty FTP cycle for engines used in vocational vehicles reflecting their primary use in transient operating conditions (typified by both frequent accelerations and decelerations), as well as in some steady cruise conditions as represented on the Heavy-duty FTP. The primary reason the agencies proposed two separate certification cycles for HD diesel engines—one for HD diesel engines used in combination tractors and the other for HD diesel engines used in vocational vehicles—is to encourage engine manufacturers to install technologies appropriate to the intended use of the engine with the vehicle. [145]

DTNA, Cummins, EMA/TMA, and Honeywell commented that certain vocational vehicle applications would achieve greater fuel consumption and CO 2 emissions reductions in-use by using an engine designed to meet the SET-based standard. They stated that some vocational vehicles operate at steady-state more frequently than in transient operation, such as motor coaches, and thus should be able to have an engine certified on a steady-state cycle to better reflect the vehicle's real use.

In response, while the agencies recognize the value to manufacturers of having additional flexibility that allows them to meet the standards in a way most consistent with how their vehicles and engines will ultimately be used, we remain concerned about increasing flexibility in ways that might impair fuel consumption and CO 2 emissions reductions. The agencies are therefore providing the option in these final rules for some vocational vehicles, but not others, to have SET certified engines. Heavy heavy-duty vocational engines will be allowed to be SET certified for vocational vehicles, since SET certified HHD engines must meet more stringent GHG and fuel consumption standards than FTP certified engines. We believe this will provide manufacturers additional flexibility while still achieving the expected fuel consumption and CO 2 emissions reductions. However, medium heavy-duty vocational engines will not be allowed to be SET-certified, because medium heavy-duty engines certified on the FTP must meet a more stringent standard than engines certified on the SET, and the agencies are not confident that fuel consumption and CO 2 emissions reduction levels would necessarily be maintained.

As discussed above in Section II.B.2.b, the agencies place important weight in making our decisions about the cost-effectiveness of the standards and the availability of lead time on the fact that engine manufacturers are expected to redesign and upgrade their products during MYs 2014-2017. The final two-step CO 2 emission and fuel consumption standards recognize the opportunity for technology improvements over the rulemaking time frame, while reflecting the typical diesel truck manufacturers' and diesel engine manufacturers' product plan cycles. Over these four model years there will be an opportunity for manufacturers to evaluate almost every one of their engine models and add technology in a cost-effective way, consistent with existing redesign schedules, to control GHG emissions and reduce fuel consumption. The time-frame and levels for the standards, as well as the ability to average, bank and trade credits and carry a deficit forward for a limited time, are expected to provide manufacturers the time needed to incorporate technology that will achieve the final GHG and fuel consumption reductions, and to do this as part of the normal engine redesign process. This is an important aspect of the final rules, as it will avoid the much higher costs that would occur if manufacturers needed to add or change technology at times other than these scheduled redesigns. [146] This time period will also provide manufacturers the opportunity to plan for compliance using a multi-year time frame, again in accord with their normal business practice. Further details on lead time, redesigns and technical feasibility can be found in Section III.

The agencies recognize, however, that the schedule of changes for the final standards may not be the most cost-effective one for all manufacturers. For HD diesel engines for use in tractors, the agencies discussed above in Section II.B.2.b our decision in this final program to allow an “OBD phase-in” option for meeting the standards, based on comments received from several industry organizations indicating that aligning technology changes for multiple regulatory requirements would provide them with greater flexibility. In the context of HD diesel engines for use in vocational vehicles, Volvo, EMA/TMA, and DDC specifically requested an “OBD phase-in” option in its comments to the NPRM. DDC argued that bundling design changes where possible can reduce the burden on industry for complying with regulations, so aligning the introduction of the OBD, GHG, and fuel consumption standards could help reduce the resources devoted to validation of new product designs and certification.

The agencies have the same interest in providing this flexibility for manufacturers of HD diesel engines for use in vocational vehicles as in providing it for manufacturers of HD diesel engines for use in combination tractors, as long as equivalent emissions and fuel savings are maintained. Thus, in order to provide additional flexibility for manufacturers looking to align their technology changes with multiple regulatory requirements, the agencies are finalizing an alternate “OBD phase-in” option for meeting the HD diesel engine standards which delivers equivalent CO 2 emissions and fuel consumption reductions as the primary standards for the engines built in the 2013 through 2017 model years, as shown in Table II-18.

Table II-18—Comparison of CO 2 reductions for the Engine Standards Under the Alternative OBD Phase-in and Primary Phase-In Back to Top
HHD FTP LHD/MHD FTP
Primary phase-in standard (g/bhp-hr) Optional phase-in standard (g/bhp-hr) Difference in lifetime CO 2 engine emissions (MMT) Primary phase-in standard (g/bhp-hr) Optional phase-in standard (g/bhp-hr) Difference in lifetime CO 2 engine emissions (MMT)
Baseline 584 584 630 630  
2013 MY Engine 584 577 20 630 618 14
2014 MY Engine 567 577 −28 600 618 −22
2015 MY Engine 567 577 −28 600 618 −22
2016 MY Engine 567 555 34 600 576 29
2017 MY Engine 555 555 0 576 576 0
Net Reductions (MMT) −3 0

Table II-19 presents the final HD diesel engine CO 2 emission and fuel consumption standards under the optional “OBD phase-in” option.

Table II-19—Optional Heavy-Duty Engine Standard Phase-in Back to Top
Model year Standard Light heavy-duty diesel Medium heavy-duty diesel Heavy heavy-duty diesel
2013 CO 2 Standard (g/bhp-hr) 618 618 577
Voluntary Fuel Consumption Standard (gallon/100 bhp-hr) 6.07 6.07 5.67
2016 and Later CO 2 Standard (g/bhp-hr) 576 576 555
Fuel Consumption (gallon/100 bhp-hr) 5.66 5.66 5.45

In order to ensure equivalent CO 2 and fuel consumption reductions and orderly compliance, and to avoid gaming, the agencies are requiring that if a manufacturer selects the OBD phase-in option, it must certify its engines starting in the 2013 model year and continue using this phase-in through the 2016 model year. Manufacturers may opt into the OBD phase-in option through the voluntary NHTSA program, but must opt in in the 2013 model year and continue using this phase-in through the 2016 model year. Manufacturers that opt in to the voluntary NHTSA program in 2014 and 2015 will be required to meet the primary phase-in schedule and may not adopt the OBD phase-in option.

As discussed above in Section II.B.2.b, while the agencies believe that the HD diesel engine standards are appropriate, cost-effective, and technologically feasible in the rulemaking time frame, we also recognize that when regulating a category of engines for the first time, there will be individual products that may deviate significantly from the baseline level of performance, whether because of a specific approach to criteria pollution control, or due to engine calibration for specific applications or duty cycles. That earlier discussion described HD diesel engines for use in combination tractors, but the same supporting information is relevant to the agencies' consideration of an alternate standard for HD diesel engines installed in vocational vehicles. In the NPRM, the agencies proposed an optional engine standard for HD diesel engines installed in vocational vehicles based on a five percent reduction from the engine's own 2011 model year baseline level, but requested comment on whether a two percent reduction would be more appropriate. [147] The comments received in response did not directly address engines for vocational vehicles, but the agencies believe that the information provided by Navistar and others is equally applicable to HD diesel engines for combination tractors and for vocational vehicles. Our assessment for the final standards is that a 2.5 percent reduction is appropriate for LHD and MHD engines installed in vocational vehicles and 3 percent is appropriate for HHD engines installed in vocational vehicles given the technologies available for application to legacy products by model year 2014. [148] Unlike the majority of engine products in this segment, engine manufacturers have devoted few resources to developing technologies for these legacy products reasoning that the investment would have little value if the engines are to be substantially redesigned or replaced in the next five years. Hence, although the technologies we have identified to achieve the proposed five percent reduction would theoretically work for these legacy products, there is inadequate lead time for manufacturers to complete the pre-application development needed to add the technology to these engines by 2014. The mix of technologies available off the shelf for legacy engines varies between engine lines within OEMs and varies among OEMs as well. On average, based on our review of manufacturer development history and current plans, we project that for the legacy products approximately half of the defined technologies appropriate for the 2014 standard will be available and ready for application by 2014 for older legacy engine designs. Hence, we have concluded that if we limit the reductions to those improvements which reflect further enhancements of already installed systems rather than the addition or replacement of technologies with fully developed new on the shelf components, the potential improvement for the 2014 model year will be 2.5 percent for LHD and MHD engines and 3 percent HHD engines.

Just as for HD diesel engines used in combination tractors, the agencies stress that this option for HD engines used in vocational vehicles is temporary and limited and is being adopted to address diverse manufacturer needs associated with complying with this first phase of the regulations. This optional, alternative standard will be available only for the 2014 through 2016 model years, because we believe that manufacturers will have had ample opportunity to make appropriate changes to bring their product performance into line with the rest of the industry after that time. This optional standard will not be available unless and until a manufacturer has exhausted all available credits and credit opportunities, and engines under the alternative standard could not generate credits.

The agencies note that manufacturers choosing to utilize this option in MYs 2014-2016 will have to make a greater relative improvement in MY 2017 than the rest of the industry, since they will be starting from a worse level. For compliance purposes, in MYs 2014-2016 emissions from engines certified and sold at the alternate level will be averaged with emissions from engines certified and sold at more stringent levels to arrive at a weighted average emissions level for all engines in the subcategory. Again, this option can only be taken if all other credit opportunities have been exhausted and the manufacturer still cannot meet the primary standards. If a manufacturer chooses this option to meet the EPA emission standards in MY 2014-2016, and wants to opt into the NHTSA fuel consumption program in these same MYs it must follow the exact path followed under the EPA program utilizing equivalent fuel consumption standards.

As discussed above in Section II.B.2.b, Volvo argued that manufacturers could game the standard by establishing an artificially high 2011 baseline emission level. This could be done, for example, by certifying an engine with high fuel consumption and GHG emissions that is either: (1) Not sold in significant quantities; or (2) later altered to emit fewer GHGs and consume less fuel through service changes. In order to mitigate this possibility, the agencies are requiring either that the 2011 model year baseline must be developed by averaging emissions over all engines in an engine averaging set certified and sold for that model year so as to prevent a manufacturer from developing a single high GHG output engine solely for the purpose of establishing a high baseline or meet additional criteria. The agencies are allowing manufacturers to combine light heavy-duty and medium heavy-duty diesel engines into a single averaging set for this provision because the engines have the same GHG emissions and fuel consumption standards. If a manufacturer does not certify all engine families in an averaging set to the alternate standards, then the tested configuration of the engine certified to the alternate standard must have the same engine displacement and its rated power within 5 percent of the highest rated power as the baseline engine. In addition, the tested configurations must have a BSFC equivalent to or better than all other configurations within the engine family and represent a configuration that is sold to customers.

(ii) Gasoline Engine Standard

Heavy-duty gasoline engines are also used in vocational vehicle applications. The number of engines certified in the past for this segment of vehicles is very limited and has ranged between three and five engine models. [149] Unlike the heavy-duty diesel engines typical of this segment which are built for vocational vehicles, these gasoline engines are developed for heavy-duty pickup trucks and vans primarily, but are also sold as loose engines to vocational vehicle manufacturers, for use in vocational vehicles such as some delivery trucks. Some fleets still prefer gasoline engines over diesel engines. In the past, this was the case since gasoline stations were more prevalent than stations that sold diesel fuel. Because they are developed for HD pickups and vans, the agencies evaluated these engines in parallel with the heavy-duty pickup truck and van standard development. As in the pickup truck and van segment, the agencies anticipated that the manufacturers will have only one engine re-design within the 2014-2018 model years under consideration within the proposal. The agencies therefore proposed fuel consumption and CO 2 emissions standards for gasoline engines for use in vocational vehicles, which represent a five percent reduction in CO 2 emissions and fuel consumption in the 2016 model year over the 2010 MY baseline through use of technologies such as coupled cam phasing, engine friction reduction, and stoichiometric gasoline direct injection.

In our meetings with all three of the major manufacturers in the HD pickup and van segment, confidential future product plans were shared with the agencies. Reflecting those plans and our estimates for when engine changes will be made in alignment with those product plans, we had concluded for proposal that the 2016 model year reflects the most logical model year start date for the heavy-duty gasoline engine standards. In order to meet the standards we are finalizing for heavy-duty pickups and vans, we project that all manufacturers will have redesigned their gasoline engine offerings by the start of the 2016 model year. Given the small volume of loose gasoline engine sales relative to complete heavy-duty pickup sales, we think it is appropriate to set the timing for the heavy-duty gasoline engine standard in line with our projections for engine redesigns to meet the heavy-duty pickup truck standards. Therefore, NHTSA's final fuel consumption standard and EPA's final CO 2 standard for heavy-duty gasoline engines are first effective in the 2016 model year.

The baseline 2010 model year CO 2 performance of these heavy-duty gasoline engines over the Heavy-duty FTP cycle is 660 g CO 2/bhp-hr (7.43 gal/100 bhp-hr) in 2010 based on non-GHG certification data provided to EPA by the manufacturers. The agencies are finalizing 2016 model year standards that require manufacturers to achieve a five percent reduction in CO 2 compared to the 2010 MY baseline through use of technologies such as coupled cam phasing, engine friction reduction, and stoichiometric gasoline direct injection. Additional detail on technology feasibility is included in Section III and in the RIA Chapter 2. As shown in Table II-20, NHTSA is finalizing as proposed a 7.06 gallon/100 bhp-hr standard for fuel consumption while EPA is adopting as proposed a 627 g CO 2/bhp-hr standard tested over the Heavy-duty FTP, effective in the 2016 model year. Similar to EPA's non-GHG standards approach, manufacturers may generate and use credits by the same engine averaging set to show compliance with both agencies' standards.

Table II-20—Heavy-Duty Gasoline Engine Standards Back to Top
Model year Gasoline engine standard
2016 and Later CO 2 Standard (g/bhp-hr) 627
Fuel Consumption (gallon/100 bhp-hr) 7.06

(c) In-Use Standards

Section 202(a)(1) of the CAA specifies that emissions standards are to be applicable for the useful life of the vehicle. The in-use standards that EPA is finalizing apply to individual vehicles and engines. NHTSA is not finalizing in-use standards that would apply to the vehicles and engines in a similar fashion.

EPA proposed that the in-use standards for heavy-duty engines installed in vocational vehicles be established by adding an adjustment factor to the full useful life emissions results projected in the EPA certification process to account for measurement variability inherent in testing done at different laboratories with different engines. The agency proposed a two percent adjustment factor and requested comments and additional data during the proposal to assist in developing an appropriate factor level. The agency received additional data during the comment period which identified production variability which was not accounted for at proposal. Details on the development of the final adjustment factor are included in RIA Chapter 3. Based on the data received, EPA determined that the adjustment factor in the final rules should be higher than the proposed level of two percent. EPA is finalizing a three percent adjustment factor for the in-use standard to provide a reasonable margin for production and test-to-test variability that could result in differences between the initial emission test results and emission results obtained during subsequent in-use testing.

We are finalizing regulatory text (in § 1036.150) to allow engine manufacturers to used assigned deterioration factors (DFs) without performing their own durability emission tests or engineering analysis. However, the engines would still be required to meet the standards in actual use without regard to whether the manufacturer used the assigned DFs. This allowance is being adopted as an interim provision applicable only for this initial phase of standards.

Manufacturers will be allowed to use an assigned additive DF of 0.0 g/bhp-hr for CO 2 emissions from any conventional engine (i.e., an engine not including advance or innovative technologies). Upon request, we could allow the assigned DF for CO 2 emissions from engines including advance or innovative technologies, but only if we determine that it would be consistent with good engineering judgment. We believe that we have enough information about in-use CO 2 emissions from conventional engines to conclude that they will not increase as the engines age. However, we lack such information about the more advanced technologies.

EPA proposed that the useful life for these engines and vehicles with respect to GHG emissions be set equal to the respective useful life periods for criteria pollutants. EPA proposed that the existing engine useful life periods, as included in Table II-21, be broadened to include CO 2 emissions and fuel consumption for both engines and vocational vehicles. The agency did not receive any adverse comments with this approach and is finalizing the useful life periods as proposed (see 40 CFR 1036.108(d) and 1037.105). While NHTSA will use useful life considerations for establishing fuel consumption performance for initial compliance and for ABT, NHTSA does not intend to implement an in-use compliance program for fuel consumption, because it is not required under EISA and because it is not currently anticipated there will be notable deterioration of fuel consumption over the engines' useful life.

Table II-21—Useful Life Periods Back to Top
Years Miles
Class 2b-5 Vocational Vehicles, Spark Ignited, and Light Heavy-Duty Diesel Engines 10 110,000
Class 6-7 Vocational Vehicles and Medium Heavy-Duty Diesel Engines 10 185,000
Class 8 Vocational Vehicles and Heavy Heavy-Duty Diesel Engines 10 435,000

(2) Test Procedures and Related Issues

The agencies are finalizing test procedures to evaluate fuel consumption and CO 2 emissions of vocational vehicles in a manner very similar to Class 7 and Class 8 combination tractors. This section describes the simulation model for demonstrating compliance, engine test procedures, and a test procedure for evaluating hybrid powertrains (a potential means of generating credits, although not part of the technology package on which the final standard for vocational vehicles is premised).

(a) Computer Simulation Model

As previously mentioned, to achieve the goal of reducing emissions and fuel consumption for both trucks and engines, we are finalizing separate engine and vehicle-based emission and fuel consumption standards for vocational vehicles and engines used in those vehicles. For the vocational vehicles, engine manufacturers are subject to the engine standards, and chassis manufacturers are required to install certified engines in their chassis. The chassis manufacturer is subject to a separate vehicle-based standard that uses the final vehicle simulation model, the GEM, to evaluate the impact of the tire design to determine compliance with the vehicle standard.

A simulation model, in general, uses various inputs to characterize a vehicle's properties (such as weight, aerodynamics, and rolling resistance) and predicts how the vehicle would behave on the road when it follows a driving cycle (vehicle speed versus time). On a second-by-second basis, the model determines how much engine power needs to be generated for the vehicle to follow the driving cycle as closely as possible. The engine power is then transmitted to the wheels through transmission, driveline, and axles to move the vehicle according to the driving cycle. The second-by-second fuel consumption of the vehicle, which corresponds to the engine power demand to move the vehicle, is then calculated according to the fuel consumption map embedded in the compliance model. Similar to a chassis dynamometer test, the second-by-second fuel consumption is aggregated over the complete drive cycle to determine the fuel consumption of the vehicle.

NHTSA and EPA are finalizing an approach consistent with the proposal to evaluate fuel consumption and CO 2 emissions respectively through a simulation of whole-vehicle operation, consistent with the NAS recommendation to use a truck model to evaluate truck performance. The EPA developed the GEM for the specific purpose of this rulemaking to evaluate vehicle performance. The GEM is similar in concept to a number of vehicle simulation tools developed by commercial and government entities. The model developed by the EPA and finalized here was designed for the express purpose of vehicle compliance demonstration and is therefore simpler and less configurable than similar commercial products. This approach gives a compact and quicker tool for evaluating vehicle compliance without the overhead and costs of a more complicated model. Details of the model, including changes made to the model to address concerns of the peer reviewers and commenters are included in Chapter 4 of the RIA. An example of the GEM input screen is shown in Figure II-4.

EPA and NHTSA have validated the GEM simulation of vocational vehicles against a commonly used simulation tool used in industry, GT-Drive, for each vocational vehicle subcategory. Prior to using GT-Drive as a comparison tool, the agencies first benchmarked a GT-Drive simulation of the combination tractor tested at Southwest Research against the experimental test results from the chassis dynamometer in the same manner as done for GEM. Then the EPA developed three vocational vehicle models (LHD, MHD, and HHD) and simulated them using both GEM and GT-Drive. Overall, the GEM and GT-Drive predicted the fuel consumption and CO 2 emissions for all three vocational vehicle subcategories with differences of less than 2 percent for the three test cycles—the California ARB Transient cycle, 55 mph cruise, and 65 mph cruise cycle. [150] The final simulation model is described in greater detail in RIA Chapter 4 and is available for download by interested parties at (http://www.epa.gov/otaq/).

The agencies are requiring that for demonstrating compliance, a chassis manufacturer would measure the performance of tires, input the values into GEM, and compare the model's output to the standard. As explained earlier, low rolling resistance tires are the only technology on which the agencies' own feasibility analysis for these vehicles is predicated. The input values for the simulation model will be derived by the manufacturer from the final tire test procedure described in this action. The remaining model inputs will be fixed values pre-defined by the agencies. These are detailed in the RIA Chapter 4, including the engine fuel consumption map to be used in the simulation.

(b) Tire Rolling Resistance Assessment

In terms of how tire rolling resistance would be measured, the agencies proposed to require that the tire rolling resistance input to the GEM be determined using ISO 28580:2009(E), Passenger car, truck and bus tyres—Methods of measuring rolling resistance—Single point test and correlation of measurement results. [151] The agencies stated that they believed the ISO test method was the most appropriate for this program because the method is the same one used by the NHTSA tire fuel efficiency consumer information program, [152] by European regulations, [153] and by the EPA SmartWay program.

The NPRM also discussed the potential for tire-to-tire variability to confound rolling resistance measurement results for LRR tires—that is, different tires of the same tire model could turn out to have different rolling resistance measurements when run on the same test. NHTSA's research during the development of the light-duty vehicle tire fuel efficiency consumer information program identified several sources of variability including test procedures, test equipment and the tires themselves, but found that all of the existing test methods had similar levels of and sources of variability. [154] The agencies proposed to address production tire-to-tire variability by specifying that three tire samples within each tire model be tested three times each, and that the average of the nine tests would be used as the Rolling Resistance Coefficient (CRR) for the tire, which would be the basis for the rolling resistance value for that tire that the manufacturer would enter into the GEM. The agencies requested comment on this proposed method. [155]

The agencies received many comments on the subject of tire rolling resistance, including suggestions for alternative test procedures and compliance issues. Regarding whether the agencies should base tire CRR inputs for the GEM on the use of the ISO 28580 test procedure, the American Automotive Policy Council (AAPC) argued that the agencies should instead require the SAE J2452 Coastdown test method for calculating tire rolling resistance, which the commenter stated was preferred by OEMs because it simulates the use of tires on actual vehicles rather than the ISO procedure which tests the tire by itself. The Rubber Manufacturers Association (RMA) argued, in contrast, that the agencies should use the SAE J1269 multi-point test, which is currently the basis for the EPA SmartWay [TM] CRR baseline values. RMA also argued that the SAE J1269 multi-point test can be used to accurately predict truck/bus tire CRR at various loads and inflations, including at the ISO 28580 load and inflation conditions, and that therefore the agencies should use the SAE test, or if the agencies want to use ISO, they should accept results from the SAE test and just correlate them. Regarding compliance obligations, RMA further argued that it was not clear how or in what format testing information would need to be provided in order to be in compliance with the proposed requirement at § 1037.125(i).

The agencies analyzed many comments on the subject of tire rolling resistance. One of the primary concerns raised in comments was that the proposed test protocol and measurement methodology would not adequately address production tire variability and measurement variability. Commenters stated that machine-to-machine differences are a significant source of variation, and this variation would make it difficult for manufacturers to be confident that the agency would assign the same CRR to a tire was tested for compliance purposes. Commenters argued that the ISO 28580 test method is unique in that it specifies a procedure to correlate results between different test equipment (i.e., different rolling resistance test machines), but not all aspects of the ISO procedure have been completely defined. Commenters stated that under ISO 28580, the lab alignment procedure depends on the specification of a reference test machine to which all other labs will align their measurement results. RMA particularly emphasized the need for establishing a tire testing reference lab for use with ISO 28580, referencing the European Tyre and Rim Technical Organization (ETRTO) estimate that CRR values could vary as much as 20 percent absent an inter-laboratory alignment procedure. RMA stated the agencies should specify a reference laboratory with the designation proposed in a supplemental notice that provides public comment. In addition, RMA commented that the extra burden proposed by the agencies for testing three tires, three times each is nine times more burdensome than what is required through the ISO procedure.

Based on the additional tire rolling resistance research conducted by the agencies, we have decided to use the ISO 28580 test procedure, as proposed, to measure tire performance for these final rules.

The agencies believe this test procedure provides two advantages over other test methods. First, the ISO 28580 test method is unique in that it specifies a procedure to correlate results between different test equipment (i.e., different tire rolling resistance test machines). This is important because NHTSA's research conducted for the light-duty tire fuel efficiency program indicated that machine-to-machine differences are a source of variation. [156] In addition, the ISO 28580 test procedure is either used, or proposed to be used, by several groups including the European Union through Regulation (EC) No 661/2009 [157] and the California Air Resources Board (CARB) through a staff recommendation for a California regulation, [158] and the EPA SmartWay program. Using the ISO 28580 may help reduce burden on manufacturers by allowing a single test protocol to be used for multiple regulations and programs. While we recognize that commenters recommended the use of other test procedures, like SAE J1269, the agencies have determined there is no established data conversion method from the SAE J1269 vehicle condition for vocational vehicle tires to the ISO 28580 single point condition at this time, and that given our reasonable preference for the ISO procedure, it would not be practical to attempt to include the use of the SAE J1269 procedure as an optional way of determining CRR values for the GEM inputs.

The agencies received comments from the Rubber Manufacturers Association, Michelin, and Bridgestone which identified the need to develop a reference lab and alignment tires. Because the ISO has not yet specified a reference lab and machine for the ISO 28580 test procedure, NHTSA announced in its March 2010 final rule concerning the light-duty tire fuel efficiency consumer information program that NHTSA would specify this laboratory for the purposes of implementing that rule so that tire manufacturers would know the identity of the machine against which they may correlate their test results. NHTSA has not yet announced the reference test machine(s) for the tire fuel efficiency consumer information program. Therefore, for the light-duty tire fuel efficiency rule, the agencies are postponing the specification of a procedure for machine-to-machine alignment until a tire reference lab is established. The agencies anticipate establishing this lab in the future with intentions for the lab to accommodate the light-duty tire fuel efficiency program.

Under the ISO 28580 lab alignment procedure, machine alignment is conducted using batches of alignment tires of two models with defined differences in rolling resistance that are certified on a reference test machine. ISO 28580 specifies requirements for these alignment tires (“Lab Alignment Tires” or LATs), but exact tire sizes or models of LATs are not specifically identified in ISO 28580. Because the test procedure has not been finalized and heavy-duty LATs are not currently defined, the agencies are postponing the use of these elements of ISO 28580 to a future rulemaking. The agencies also note the lab-to-lab comparison conducted in the most recent EPA tire test program mentioned previously. The agencies reviewed the CRR data from the tires that were tested at both the STL and Smithers laboratories to assess inter-laboratory and machine variability. The agencies conducted statistical analysis of the data to gain better understanding of lab-to-lab correlation and developed an adjustment factor for data measured at each of the test labs. Based on these results, the agencies believe the lab-to-lab variation for the STL and Smithers laboratories would have very small effect on measured CRR values. Based on the test data, the agencies judge that it is reasonable to implement the HD program with current levels of variability, and to allow the use of either Smithers or STL laboratories for determining the CRR value in the HD program, or demonstrate that the test facilities will not bias results low relative to Smithers or STL laboratories.

RMA also commented that the extra burden proposed by the agencies for testing three tires, three times each is nine times more burdensome than what is required through the ISO procedure. Since the proposal, EPA obtained replicate test data for a number of Class 8 combination tractor tires from various manufacturers. Some of these were tires submitted to SmartWay for verification, while some were tires tested by manufacturers for other purposes. Three tire model samples for 11 tire models were tested using the ISO 28580 test. [159] A mean and a standard deviation were calculated for each set of three replicate measurements performed on each tire of the 3-tire sample. The coefficient of variability (COV) of the CRR was calculated by dividing the standard deviation by the mean. The values of COV ranged from 0 percent (no measurable variability) to six percent. In addition, during the period September 2010 and June 2011, EPA contracted with Smithers-Rapra to select and test for rolling resistance using ISO 28580 for a representative sample of Class 4-8 vocational vehicle tires. As part of the test, 10 tires were selected for replicate testing. [160] Three replicate tests were conducted for each of the tires, to evaluate test variability only. The COV of the RR C results ranged from nearly 0 to 2 percent, with a mean of less than 1 percent. Based on the results of these two testing programs, the agencies determined that the impact of production variability is greater than the impact of measurement variability. Thus, the agencies concluded that the extra burden of testing a single tire three times was not necessary to obtain accurate results, but the variability of RR C results due to manufacturing of the tires is significant to continue to require testing of three tire samples for each tire model. In summary, we are allowing manufacturers to determine the rolling resistance coefficient of the heavy-duty tires by testing three tire samples one time each.

For the final rules, the agencies are also including a warm up cycle as part of the procedure for bias ply tires to allow these tires to reach a steady temperature and volume state before ISO 28580 testing. This procedure is similar to a procedure that was developed for the light-duty tire fuel efficiency consumer information program, and was adopted from a procedure defined in Federal motor vehicle safety standard No. 109 (FMVSS No. 109). [161]

Finally, the agencies are including testing and reporting for `single-wide' or `super-single' type tires. These tires replace the traditional `dual' wheel tire combination with a single wheel and tire that is nearly as wide as the dual combination with similar load capabilities. These tire types were developed as a fuel saving technology. The tires provide lower rolling resistance along with a reduction in weight when compared to a typical set of dual wheel tire combinations; and are one of the technologies included in the EPA SmartWay [TM] program. The agencies have learned that there is limited testing equipment available that is capable of testing single wide tires; single wide tires require a wider test machine drum than required for conventional tires. Although the number of machines available is limited, the agencies believe the equipment is adequate for the testing and reporting of CRR for this program.

As discussed above, the agencies are taking the approach of using CRR for the HD fuel efficiency and greenhouse gas program to align with the measurement methodology already employed or proposed by the EPA SmartWay program, the European Union Regulation (EC) No 661/2009 [162] and the California Air Resources Board (CARB) through a staff recommendation for a California regulation. [163] In the NPRM, the agencies proposed to use CRR, but for purposes of developing these final rules, the agencies also evaluated whether to use CRR or Rolling Resistance Force (RR F) as the measurement for tire rolling resistance for the GEM input. The agencies considered RR F largely because in the NPRM for Passenger Car Tire Fuel Efficiency (TFE) program, NHTSA had proposed to use RR F. A key distinction between these two programs, and their associated metrics, are the differences in how the measurement data are used and who uses the data. In particular, the HD fuel efficiency and GHG emissions program is a compliance program using information developed by and for technical personnel at manufacturers and agencies to determine a vehicle's compliance with regulations. The TFE program, in contrast, is a consumer education program intended to inform consumers making purchase decisions regarding the fuel saving benefits of replacement passenger car tires. The target audiences are much different for the two programs which in turn affect how the information will be used. The agencies believe that RR F may be more intuitive for non-technical people because tires that are larger and/or that carry higher loads will generally have numerically higher RR F values than smaller tires and/or tires that carry lower loads. CRR values generally follow an opposite trend, where tires that are larger and/or carry higher loads will generally have numerically lower CRR values than smaller tires and/or tires that carry lower loads. The agencies believe this key distinction helps define the type of metrics to be used and communicated in accordance with their respective purposes.

Additionally, the CRR metric for use in the MD/HD program is not susceptible to the skew associated with tire diameter. Medium- and heavy-duty vehicle tires are available in a small fraction of the tire sizes of the passenger market and, for the most part, are larger tires than those found on passenger cars. When viewing CRR over a larger range of sizes, small diameter tires tend to appear as having a lower performance, which is not necessarily accurate, with the converse occurring as the diameter increases.

Using the CRR value for determining the rolling resistance also takes into account the load carrying capability for the tire being tested, which, intuitively, can lead to some potentially confusing results. Several vocational vehicle manufacturers argued in their comments that LRR tires were not available for, e.g., vehicles like refuse trucks, which tend to use large diameter tires to carry very heavy loads. Based on the agencies' testing, in fact, the measured CRR (as opposed to the RR F) for refuse trucks were found to be among the best tested. This finding can be explained by considering that CRR is calculated by dividing the measured rolling resistance force by the tire's load capacity rating. Although the tire may have a relatively high rolling resistance force, the tire load capacity rating is also very high, resulting in an overall lower (better) CRR value than many other types of tires. The amount of load tire can carry (test load) contributes to a very low reported CRR, thus confirming low rolling resistance tires meeting the standards, as measured by CRR, are available to the industry regardless of segment or application.

Based on these considerations, the agencies have decided to use the CRR metric for the HD fuel efficiency and GHG emissions program.

(c) Defined Vehicle Configurations in the GEM

As discussed above, the agencies are finalizing a methodology that chassis manufacturers will use to quantify the tire rolling resistance values to be input into the GEM. Moreover, the agencies are defining the remaining GEM inputs (i.e., specifying them by rule), which differ by the regulatory subcategory (for reasons described in the RIA Chapter 4). The defined inputs, among others, include the drive cycle, aerodynamics, vehicle curb weight, payload, engine characteristics, and drivetrain for each vehicle type.

(i) Metric

Based on NAS's recommendation and feedback from the heavy-duty truck industry, NHTSA and EPA proposed standards for vocational vehicles that would be expressed in terms of moving a ton of payload over one mile. Thus, NHTSA's proposed fuel consumption standards for these vehicles would be represented as gallons of fuel used to move one ton of payload one thousand miles, or gal/1,000 ton-mile. EPA's proposed CO 2 vehicle standards would be represented as grams of CO 2 per ton-mile. The agencies received comments that a payload-based metric is not appropriate for all types of vocational vehicles, specifically buses. The agencies recognize that a payload-based approach may not be the most representative of an individual vocational application; however, it best represents the broad vocational category. The metric which we proposed treats all vocational applications equally and requires the same technologies be applied to meet the standard. Thus, the agencies are adopting the proposed metric, but will revisit the issue of metrics in any future action, if required, depending on the breadth of each standard.

(ii) Drive cycle

The drive cycles proposed for the vocational vehicles consisted of the same three modes used for the Class 7 and 8 combination tractors. The proposed cycle included the Transient mode, as defined by California ARB in the HHDDT cycle, a constant speed cycle at 65 mph and a 55 mph constant speed mode. The agencies proposed different weightings for each mode for vocational vehicles than those proposed for Class 7 and 8 combination tractors, given the known difference in driving patterns between these two categories of vehicles. The same reasoning underlies the agencies' use of the Heavy-duty FTP cycle to evaluate compliance with the standards for diesel engines used in vocational vehicles.

The variety of vocational vehicle applications makes it challenging to establish a single cycle which is representative of all such trucks. However, in aggregate, the vocational vehicles typically operate over shorter distances and spend less time cruising at highway speeds than combination tractors. The agencies evaluated for proposal two sources for mode weightings, as detailed in RIA Chapter 3. The agencies proposed the mode weightings based on the vehicle speed characteristics of single unit trucks used in EPA's MOVES model which were developed using Federal Highway Administration data to distribute vehicle miles traveled by road type. [164] The proposed weighted CO 2 and fuel consumption value consisted of 37 percent of 65 mph Cruise, 21 percent of 55 mph Cruise, and 42 percent of Transient performance.

The agencies received comments stating that the proposed drive cycles and weightings are not representative of individual vocational applications, such as buses and refuse haulers. A number of groups commented that the vocational vehicle cycle is not representative of real world driving and recommended changes to address that concern. Several organizations proposed the addition of new drive cycles to make the test more representative.

Bendix suggested using the Composite International Truck Local and Commuter Cycle (CILCC) as the general purpose mixed urban/freeway cycles and to use four representative cycles: mixed urban, freeway, city bus, refuse, and utility. Bendix suggested using the Standardized On-Road Test (SORT) cycles for vocational vehicles operating in the urban environment in addition to SORT cycles for 3 different vocations—with separate weightings. They stated that SORT with an average speed of 11.2 mph, lines up most closely with the average of transit bus duty cycles at 9.9 mph as well as the overall U.S. National average of 12.6 mph. As alternative approaches they suggested adopting the Orange County duty cycle for the urban transit bus vocation, or creating an Urban Transit Bus cycle with several possible weighting factors—all with very high percentage transient (90% to 100%), very low 55 mph (0% to 7%), very low 65 mph (0% to 3%), and an average speed of 15 to 17 mph. Bendix supported their assertions about urban bus vehicle speed with data from the 2010 American Public Transportation Association (APTA) `Fact Book' and other sources. In contrast, Bendix stated, the GEM cycle average speed is currently 32.6 mph. Such high speeds at steady state will penalize technologies such as hybridization.

Clean Air Task Force said the agencies have not adequately addressed the diversity of the vocational vehicle fleet since they are not distinguished by different duty cycles. They urged the agencies to sub-divide vocational vehicles by expected use, with separate test cycles for each sub-group in order to capture the full potential benefits of hybridization and other advanced technologies in a meaningful and accurate way in future rulemakings for MY2019 and later trucks.

Two groups cautioned that unintended consequences could result from the lack of diversity in duty cycles. DTNA said that the single drive cycle proposed for all vehicles by the agencies would likely lead to unintended consequences—such as customers being driven for regulatory reasons to purchase a transmission that does not suit their actual operation. Similarly, Volvo said medium- and heavy-duty vehicles are uniquely built for specific applications but it will not be feasible to develop regulatory protocols that can accurately predict efficiency in each application duty cycle. This trade-off could result in unintended or negative consequences in parts of the market.

Several commenters suggested changing the weightings of the cycle to more accurately reflect real world driving. Allison stated that the vocational vehicle cycle includes too much steady state driving time. They suggested (with supporting data from the Oakridge National Laboratory analysis) reducing steady state driving at 60 mph to minimal or no time on the cycle to address this problem. Allison commented that GEM contains lengthy accelerations to reach 55 and 65 miles per hour—much longer than is required in real world driving. They supported this statement with data from a testing program conducted at Oakridge National Laboratory showing medium- and heavy-duty vehicles accelerate more rapidly than in the GEM drive cycle. According to Allison, this long acceleration time in the GEM, coupled with too much steady state operation with very little variation, is not representative of vocational vehicle operation. In addition, Allison said that the GEM does not adequately account for shift time, clutch profile, turbo lag, and other impacts on both steady state and transient operation. The impact, they state, is that the cycle will hinder proper deployment of technologies to reduce fuel consumption and GHG emissions.

BAE focused their comments on urban transit bus operation. They stated the weighting factors for steady state operation are inconsistent with urban transit bus cycles.

Other commenters suggested the agencies develop chassis dynamometer tests based on the engine (FTP) test. Cummins said that chassis dynamometer testing should allow the use of average vehicle characteristics to determine road load and make use of the vehicle FTP and SET cycles. Others commented that the correlation between the FTP and the UDDS is poor.

After careful consideration of the comments, the agencies are adopting the proposed drive cycles. The final drive cycles and weightings represent the straight truck operations which dominate the vehicle miles travelled by vocational vehicles. The agencies do not believe that application-specific drive cycles are required for this final action because the program is based on the generally-applicable use of low rolling resistance tires. The drive cycles that we are adopting treat all vocational applications equally predicate standard stringency on use of the same technology (LRR tires) to meet the standard. The drive cycles in the final rule accurately reflect the performance of this technology. The agencies are also finalizing, as proposed, the mode weightings based on the vehicle speed characteristics of single unit trucks used in EPA's MOVES model which were developed using Federal Highway Administration data to distribute vehicle miles traveled by road type. [165] Similar to the issue of metrics discussed above, the agencies may revisit drive cycles and weightings in any future regulatory action to develop standards specific to applications.

(iii) Empty Weight and Payload

The total weight of the vehicle is the sum of the tractor curb weight and the payload. The agencies are proposed to specify each of these aspects of the vehicle. The agencies developed the proposed vehicle curb weight inputs based on industry information developed by ICF. [166] The proposed curb weights were 10,300 pounds for the LHD trucks, 13,950 pounds for the MHD trucks, and 29,000 pounds for the HHD trucks.

NHTSA and EPA proposed payload requirements for each regulatory category developed from Federal Highway statistics based on averaging the payloads for the weight categories represented within each vehicle subcategory. [167] The proposed payloads were 5,700 pounds for the Light Heavy-Duty trucks, 11,200 pounds for Medium Heavy-Duty trucks, and 38,000 pounds for Heavy Heavy-Duty trucks.

The agencies received comments from several stakeholders regarding the proposed curb weights and payloads for vocational vehicles. BAE said a Class 8 transit bus has a typical curb weight of 27,000 pounds and maximum payload of 15,000 pounds. Daimler commented that Class 8 buses have a GVWR of 42,000 pounds. Autocar said that Class 8 refuse trucks typically have a curb weight of 31,000 to 33,000 pounds, typical average payload of 10,000 pounds, and typical maximum payload of 20,000 pounds.

Upon further consideration, the agencies are reducing the assigned weight of heavy heavy-duty vocational vehicles. While we still believe the proposed values are appropriate for some vocational vehicles, we reduced the total weight to bring it closer to some of the lighter vocational vehicles. The agencies are adopting final curb weights of 10,300 pounds for the LHD trucks, 13,950 pounds for the MHD trucks, and 27,000 pounds for the HHD trucks. The agencies are also adopting payloads of 5,700 pounds for the Light Heavy-Duty trucks, 11,200 pounds for Medium Heavy-Duty trucks, and 15,000 pounds for Heavy Heavy-Duty trucks. Additional information is available in RIA Chapter 3.

(iv) Engine

As the agencies are finalizing separate engine and vehicle standards, the GEM will be used to assess the compliance of the chassis with the vehicle standard. To maintain the separate assessments, the agencies are adopting the proposed approach of using fixed values that are predefined by the agencies for the engine characteristics used in GEM, including the fuel consumption map which provides the fuel consumption at hundreds of engine speed and torque points. If the agencies did not standardize the fuel map, then a vehicle that uses an engine with emissions and fuel consumption better than the standards would require fewer vehicle reductions than those being finalized. As proposed, the agencies are using diesel engine characteristics in the GEM, as most representative of the largest fraction of engines in this market. The agencies did not receive any adverse comments to using this approach.

The agencies are finalizing two distinct sets of fuel consumption maps for use in GEM. The first fuel consumption map would be used in GEM for the 2014 through 2016 model years and represent a diesel engine which meets the 2014 model year engine CO 2 emissions standards. A second fuel consumption map would be used beginning in the 2017 model year and represents a diesel engine which meets the 2017 model year CO 2 emissions and fuel consumption standards and accounts for the increased stringency in the final MY 2017 standard). The agencies have modified the 2017 MY heavy heavy-duty diesel fuel map used in the GEM for the final rulemaking to address comments received. Details regarding this change can be found in RIA Chapter 4.4.4. Effectively there is no change in stringency of the vocational vehicle standard (not including the engine) between the 2014 MY and 2017 MY standards for the full rulemaking period. These inputs are reasonable (indeed, seemingly necessitated) given the separate final regulatory requirement that vocational vehicle chassis manufacturers use only certified engines.

(v) Drivetrain

The agencies' assessment of the current vehicle configuration process at the truck dealer's level is that the truck companies provide software tools to specify the proper drivetrain matched to the buyer's specific circumstances. These dealer tools allow a significant amount of customization for drive cycle and payload to provide the best specification for the customer. The agencies are not seeking to disrupt this process. Optimal drivetrain selection is dependent on the engine, drive cycle (including vehicle speed and road grade), and payload. Each combination of engine, drive cycle, and payload has a single optimal transmission and final drive ratio. The agencies are specifying the engine's fuel consumption map, drive cycle, and payload; therefore, it makes sense to specify the drivetrain that matches.

(d) Engine Metrics and Test Procedures

EPA proposed that the GHG emission standards for heavy-duty engines under the CAA would be expressed as g/bhp-hr while NHTSA's proposed fuel consumption standards under EISA, in turn, be represented as gal/100 bhp-hr. The NAS panel did not specifically discuss or recommend a metric to evaluate the fuel consumption of heavy-duty engines. However, as noted above they did recommend the use of a load-specific fuel consumption metric for the evaluation of vehicles. [168] An analogous metric for engines is the amount of fuel consumed per unit of work. The g/bhp-hr metric is also consistent with EPA's current standards for non-GHG emissions for these engines. The agencies did not receive any adverse comments related to the metrics for HD engines; therefore, we are adopting the metrics as proposed.

With regard to GHG and fuel consumption control, the agencies believe it is appropriate to set standards based on a single test procedure, either the Heavy-duty FTP or SET, depending on the primary expected use of the engine. EPA's criteria pollutant standards for engines currently require that manufacturers demonstrate compliance over the transient Heavy-duty FTP cycle; over the steady-state SET procedure; and during not-to-exceed testing. EPA created this multi-layered approach to criteria emissions control in response to engine designs that optimized operation for lowest fuel consumption at the expense of very high criteria emissions when operated off the regulatory cycle. EPA's use of multiple test procedures for criteria pollutants helps to ensure that manufacturers calibrate engine systems for compliance under all operating conditions. We are not concerned if manufacturers further calibrate these engines off cycle to give better in-use fuel consumption while maintaining compliance with the criteria emissions standards as such calibration is entirely consistent with the goals of our joint program. Further, we believe that setting standards based on both transient and steady-state operating conditions for all engines could lead to undesirable outcomes.

It is critical to set standards based on the most representative test cycles in order for performance in-use to obtain the intended (and feasible) air quality and fuel consumption benefits. We are finalizing standards based on the composite Heavy-duty FTP cycle for engines used in vocational vehicles reflecting these vehicles' primary use in transient operating conditions typified by frequent accelerations and decelerations as well as some steady cruise conditions as represented on the Heavy-duty FTP. The primary reason the agencies are finalizing two separate diesel engine standards—one for diesel engines used in tractors and the other for diesel engines used in vocational vehicles—is to encourage engine manufacturers to install engine technologies appropriate to the intended use of the engine with the vehicle. The current non-GHG emissions engine test procedures also require the development of regeneration emission rates and frequency factors to account for the emission changes during a regeneration event (40 CFR 86.004-28). EPA and NHTSA proposed not to include these emissions from the calculation of the compliance levels over the defined test procedures. Cummins and Daimler supported and stated sufficient incentives already exist for manufacturers to limit regeneration frequency. Conversely, Volvo opposed the omission of IRAF requirements for CO 2 emissions because emissions from regeneration can be a significant portion of the expected improvement and a significant variable between manufacturers

For the proposal, we considered including regeneration in the estimate of fuel consumption and GHG emissions and decided not to do so for two reasons. First, EPA's existing criteria emission regulations already provide a strong motivation to engine manufacturers to reduce the frequency and duration of infrequent regeneration events. The very stringent 2010 NO X emission standards cannot be met by engine designs that lead to frequent and extend regeneration events. Hence, we believe engine manufacturers are already reducing regeneration emissions to the greatest degree possible. In addition to believing that regenerations are already controlled to the extent technologically possible, we believe that attempting to include regeneration emissions in the standard setting could lead to an inadvertently lax emissions standard. In order to include regeneration and set appropriate standards, EPA and NHTSA would have needed to project the regeneration frequency and duration of future engine designs in the time frame of this program. Such a projection would be inherently difficult to make and quite likely would underestimate the progress engine manufacturers will make in reducing infrequent regenerations. If we underestimated that progress, we would effectively be setting a more lax set of standards than otherwise would be expected. Hence in setting a standard including regeneration emissions we faced the real possibility that we would achieve less effective CO 2 emissions control and fuel consumption reductions than we will achieve by not including regeneration emissions. Therefore, the agencies are finalizing an approach as proposed which does not include the regenerative emissions.

(e) Hybrid Powertrain Technology

Although the final vocational vehicle standards are not premised on use of hybrid powertrains, certain vocational vehicle applications may be suitable candidates for use of hybrids due to the greater frequency of stop-and-go urban operation and their use of power take-off (PTO) systems. Examples are vocational vehicles used predominantly in stop-start urban driving (e.g., delivery trucks). As an incentive, the agencies are finalizing to provide credits for the use of hybrid powertrain technology as described in Section IV. Under the advanced technology credit provisions, credits generated by use of hybrid powertrains could be used to meet any of the heavy-duty standards, and are not restricted to the averaging set generating the credit, unlike the other credit provisions in the final rules. The agencies are finalizing that any credits generated using such advanced technologies could be applied to any heavy-duty vehicle or engine, and not be limited to the averaging set generating the credit. Section IV below also details the final approach to account for the use of a hybrid powertrain when evaluating compliance with the vehicle standard. In general, manufacturers can derive the fuel consumption and CO 2 emissions reductions based on comparative test results using the final chassis testing procedures.

(3) Summary of Final Flexibility and Credit Provisions

EPA and NHTSA are finalizing four flexibility provisions specifically for heavy-duty vocational vehicle and engine manufacturers, as discussed in Section IV below. These are an averaging, banking and trading program for emissions and fuel consumption credits, as well as provisions for early credits, advanced technology credits, and credits for innovative vehicle or engine technologies which are not included as inputs to the GEM or are not demonstrated on the engine FTP test cycle. With the exception of the advanced technology credits, credits generated under these provisions can only be used within the same averaging set which generated the credit (for example, credits generated by HHD vocational vehicles can only be used by HHD vehicles). EPA is also adopting a temporary provision whereby N 2 O emission credits can be used to comply with the CO 2 emissions standard, as described in Section IV below.

(3) Deferral of Standards for Small Chassis Manufacturing Business and Small Business Engine Companies

EPA and NHTSA are finalizing an approach to defer greenhouse gas emissions and fuel consumption standards from small vocational vehicle chassis manufacturers meeting the SBA size criteria of a small business as described in 13 CFR 121.201 (see 40 CFR 1036.150 and 1037.150). The agencies will instead consider appropriate GHG and fuel consumption standards for these entities as part of a future regulatory action. This includes both U.S.-based and foreign small volume heavy-duty truck and engine manufacturers.

The agencies have identified ten chassis entities that appear to fit the SBA size criterion of a small business. [169] The agencies estimate that these small entities comprise less than 0.5 percent of the total heavy-duty vocational vehicle market in the United States based on Polk Registration Data from 2003 through 2007, [170] and therefore that the exemption will have a negligible impact on the GHG emissions and fuel consumption improvements from the final standards.

EPA and NHTSA have also identified three engine manufacturing entities that appear to fit the SBA size criteria of a small business based on company information included in Hoover's. [171] Based on 2008 and 2009 model year engine certification data submitted to EPA for non-GHG emissions standards, the agencies estimate that these small entities comprise less than 0.1 percent of the total heavy-duty engine sales in the United States. The final exemption from the standards established under this rulemaking would have a negligible impact on the GHG emissions and fuel consumption reductions otherwise due to the standards.

To ensure that the agencies are aware of which companies would be exempt, we are finalizing as proposed to require that such entities submit a declaration to EPA and NHTSA containing a detailed written description of how that manufacturer qualifies as a small entity under the provisions of 13 CFR 121.201, as described in Section V below.

E. Other Standards

In addition to finalizing CO 2 emission standards for heavy-duty vehicles and engines, EPA is also finalizing separate standards for N 2 O and CH 4 emissions. [172] NHTSA is not finalizing comparable separate standards for these GHGs because they are not directly related to fuel consumption in the same way that CO 2 is, and NHTSA's authority under EISA exclusively relates to fuel efficiency. N 2 O and CH 4 are important GHGs that contribute to global warming, more so than CO 2 for the same amount of emissions due to their high Global Warming Potential (GWP). [173] EPA is finalizing N 2 O and CH 4 standards which apply to HD pickup trucks and vans as well as to all heavy-duty engines. EPA is not finalizing N 2 O and CH 4 standards for the Class 7 and 8 tractor or Class 2b-8 chassis manufacturers because these emissions would be controlled through the engine program.

EPA requested comment on possible alternative CO 2 equivalent approaches to provide near-term flexibility for 2012-14 MY light-duty vehicles. As described below, EPA is finalizing alternative provisions allowing manufacturers to use CO 2 credits, on a CO 2-equivalent (CO 2 eq) basis, to meet the N 2 O and CH 4 standards, which is consistent with many commenters' preferred approach.

Almost universally across current engine designs, both gasoline- and diesel-fueled, N 2 O and CH 4 emissions are relatively low today and EPA does not believe it would be appropriate or feasible to require reductions from the levels of current gasoline and diesel engines. This is because for the most part, the same hardware and controls used by heavy-duty engines and vehicles that have been optimized for non-methane hydrocarbon (NMHC) and NO X control indirectly result in highly effective control of N 2 O and CH 4. Additionally, unlike criteria pollutants, specific technologies beyond those presently implemented in heavy-duty vehicles to meet existing emission requirements have not surfaced that specifically target reductions in N 2 O or CH 4. Because of this, reductions in N 2 O or CH 4 beyond current levels in most heavy-duty applications would occur through the same mechanisms that result in NMHC and NO X reductions and would likely result in an increase in the overall stringency of the criteria pollutant emission standards. Nevertheless, it is important that future engine technologies or fuels not currently researched do not result in increases in these emissions, and this is the intent of the final “cap” standards. The final standards would primarily function to cap emissions at today's levels to ensure that manufacturers maintain effective N 2 O and CH 4 emissions controls currently used should they choose a different technology path from what is currently used to control NMHC and NO X but also largely successful methods for controlling N 2 O and CH 4. As discussed below, some technologies that manufacturers may adopt for reasons other than reducing fuel consumption or GHG emissions could increase N 2 O and CH 4 emissions if manufacturers do not address these emissions in their overall engine and aftertreatment design and development plans. Manufacturers will be able to design and develop the engines and aftertreatment to avoid such emissions increases through appropriate emission control technology selections like those already used and available today. Because EPA believes that these standards can be capped at the same level, regardless of type of HD engine involved, the following discussion relates to all types of HD engines regardless of the vehicles in which such engines are ultimately used. In addition, since these standards are designed to cap current emissions, EPA is finalizing the same standards for all of the model years to which the rules apply.

EPA believes that the final N 2 O and CH 4 cap standards will accomplish the primary goal of deterring increases in these emissions as engine and aftertreatment technologies evolve because manufacturers will continue to target current or lower N 2 O and CH 4 levels in order to maintain typical compliance margins. While the cap standards are set at levels that are higher than current average emission levels, the control technologies used today are highly effective and there is no reason to believe that emissions will slip to levels close to the cap, particularly considering compliance margin targets. The caps will protect against significant increases in emissions due to new or poorly implemented technologies. However, we also believe that an alternative compliance approach that allows manufacturers to convert these emissions to CO 2 eq emission values and combine them with CO 2 into a single compliance value would also be appropriate, so long as it did not undermine the stringency of the CO 2 standard. As described below, EPA is finalizing that such an alternative compliance approach be available to manufacturers to provide certain flexibilities for different technologies.

EPA requested comments in the NPRM on the approach to regulating N 2 O and CH 4 emissions including the appropriateness of “cap” standards, the technical bases for the levels of the final N 2 O and CH 4 standards, the final test procedures, and the final timing for the standards. In addition, EPA requested any additional emissions data on N 2 O and CH 4 from current technology engines. We solicited additional data, and especially data for in-use vehicles and engines that would help to better characterize changes in emissions of these pollutants throughout their useful lives, for both gasoline and diesel applications. As is typical for EPA emissions standards, we are finalizing that manufacturers should establish deterioration factors to ensure compliance throughout the useful life. We are not at this time aware of deterioration mechanisms for N 2 O and CH 4 that would result in large deterioration factors, but neither do we believe enough is known about these mechanisms to justify finalizing assigned factors corresponding to no deterioration, as we are finalizing for CO 2, or for that matter to any predetermined level. In addition to N 2 O and CH 4 standards, this section also discusses air conditioning-related provisions and EPA provisions to extend certification requirements to all-electric HD vehicles and vehicles and engines designed to run on ethanol fuel.

(1) What is EPA's Approach to Controlling N 2 O?

N 2 O is a global warming gas with a GWP of 298. It accounts for about 0.3 percent of the current greenhouse gas emissions from heavy-duty trucks. [174]

N 2 O is emitted from gasoline and diesel vehicles mainly during specific catalyst temperature conditions conducive to N 2 O formation. Specifically, N 2 O can be generated during periods of emission hardware warm-up when rising catalyst temperatures pass through the temperature window when N 2 O formation potential is possible. For current heavy-duty gasoline engines with conventional three-way catalyst technology, N 2 O is not generally produced in significant amounts because the time the catalyst spends at the critical temperatures during warm-up is short. This is largely due to the need to quickly reach the higher temperatures necessary for high catalyst efficiency to achieve emission compliance of criteria pollutants. N 2 O formation is generally only a concern with diesel and potentially with future gasoline lean-burn engines with compromised NO X emissions control systems. If the risk for N 2 O formation is not factored into the design of the controls, these systems can but need not be designed in a way that emphasizes efficient NO X control while allowing the formation of significant quantities of N 2 O. However, these future advanced gasoline and diesel technologies do not inherently require N 2 O formation to properly control NO X. Pathways exist today that meet criteria emission standards that would not compromise N 2 O emissions in future systems as observed in current production engine and vehicle testing [175] which would also work for future diesel and gasoline technologies. Manufacturers would need to use appropriate technologies and temperature controls during future development programs with the objective to optimize for both NO X and N 2 O control. Therefore, future designs and controls at reducing criteria emissions would need to take into account the balance of reducing these emissions with the different control approaches while also preventing inadvertent N 2 O formation, much like the path taken in current heavy-duty compliant engines and vehicles. Alternatively, manufacturers who find technologies that reduce criteria or CO 2 emissions but see increases N 2 O emissions beyond the cap could choose to offset N 2 O emissions with reduction in CO 2 as allowed in the CO 2 eq option discussed in Section II.E.3.

EPA is finalizing an N 2 O emission standard that we believe would be met by most current-technology gasoline and diesel vehicles at essentially no cost to the vehicle, though the agency is accounting for additional N 2 O measurement equipment costs. EPA believes that heavy-duty emission standards since 2008 model year, specifically the very stringent NO X standards for both engine and chassis certified engines, directly result in stringent N 2 O control. It is believed that the current emission control technologies used to meet the stringent NO X standards achieve the maximum feasible reductions and that no additional technologies are recognized that would result in additional N 2 O reductions. As noted, N 2 O formation in current catalyst systems occurs, but their emission levels are inherently low, because the time the catalyst spends at the critical temperatures during warm-up when N 2 O can form is short. At the same time, we believe that the standard would ensure that the design of advanced NO X control systems for future diesel and lean-burn gasoline vehicles would control N 2 O emission levels. While current NO X control approaches used on current heavy-duty diesel vehicles do not compromise N 2 O emissions and actually result in N 2 O control, we believe that the standards would discourage any new emission control designs for diesels or lean-burn gasoline vehicles that achieve criteria emissions compliance at the cost of increased N 2 O emissions. Thus, the standard would cap N 2 O emission levels, with the expectation that current gasoline and diesel vehicle control approaches that comply with heavy-duty vehicle emission standards for NO X would not increase their emission levels, and that the cap would ensure that future diesel and lean-burn gasoline vehicles with advanced NO X controls would appropriately control their emissions of N 2 O.

(a) Heavy-Duty Pickup Truck and Van N 2 O Exhaust Emission Standard

EPA is finalizing the proposed per-vehicle N 2 O emission standard of 0.05 g/mi, measured over the Light-duty FTP and HFET drive cycles. Similar to the CO 2 standard approach, the N 2 O emission level of a vehicle would be a composite of the Light-duty FTP and HFET cycles with the same 55 percent city weighting and 45 percent highway weighting. The standard would become effective in model year 2014 for all HD pickups and vans that are subject to the CO 2 emission requirements. Averaging between vehicles would not be allowed. The standard is designed to prevent increases in N 2 O emissions from current levels, i.e., a no-backsliding standard.

The N 2 O standard level is approximately two times the average N 2 O level of current gasoline and diesel heavy-duty trucks that meet the NO X standards effective since 2008 model year. [176] Manufacturers typically use design targets for NO X emission levels at approximately 50 percent of the standard, to account for in-use emissions deterioration and normal testing and production variability, and we expect manufacturers to utilize a similar approach for N 2 O emission compliance. We are not adopting a more stringent standard for current gasoline and diesel vehicles because the stringent heavy-duty NO X standards already result in significant N 2 O control, and we do not expect current N 2 O levels to rise for these vehicles particularly with expected manufacturer compliance margins.

Diesel heavy-duty pickup trucks and vans with advanced emission control technology are in the early stages of development and commercialization. As this segment of the vehicle market develops, the final N 2 O standard would require manufacturers to incorporate control strategies that minimize N 2 O formation. Available approaches include using electronic controls to limit catalyst conditions that might favor N 2 O formation and considering different catalyst formulations. While some of these approaches may have associated costs, EPA believes that they will be small compared to the overall costs of the advanced NO X control technologies already required to meet heavy-duty standards.

The light-duty GHG rule requires that manufacturers begin testing for N 2 O by 2015 model year. The manufacturers of complete pickup trucks and vans (Ford, General Motors, and Chrysler) are already impacted by the light-duty GHG rule and will therefore have this equipment and capability in place for the timing of this rulemaking.

Overall, we believe that manufacturers of HD pickups and vans (both gasoline and diesel) would meet the standard without implementing any significantly new technologies, only further refinement of their existing controls, and we do not expect there to be any significant costs associated with this standard.

(b) Heavy-Duty Engine N 2 O Exhaust Emission Standard

EPA proposed a per engine N 2 O emissions standard of 0.05 g/bhp-hr for heavy-duty engines, but is finalizing a standard of 0.10 g/bhp-hr based on additional data submitted to the agency which better represents the full range of current diesel and gasoline engine performance. The final N 2 O standard becomes effective in 2014 model year for diesel engines, as proposed. However, EPA is finalizing N 2 O standards for gasoline engines that become effective in 2016 model year to align with the first year of the CO 2 gasoline engine standards. Without this alignment, manufacturers would not have any flexibility, such as CO 2 eq credits, in meeting the N 2 0 cap and therefore would not have any recourse to comply if an engine's N 2 O emissions were above the standard. The standard remains the same over the useful life of the engine. The N 2 O emissions would be measured over the composite Heavy-duty FTP cycle because it is believed that this cycle poses the highest risk for N 2 O formation versus the additional heavy-duty compliance cycles. The agencies received comments from industry suggesting that the N 2 O and CH 4 emissions be evaluated over the same test cycle required for CO 2 emissions compliance. In other words, the commenters wanted to have the N 2 O emissions measured over the SET for engines installed in tractors. The agencies are not adopting this approach for the final action because we do not have sufficient data to set the appropriate N 2 O level using the SET. The agencies are not requiring any additional burden by requiring the measurement to be conducted over the Heavy-Duty FTP cycle because it is already required for criteria emissions. Averaging of N 2 O emissions between HD engines will not be allowed. The standard is designed to prevent increases in N 2 O emissions from current levels, i.e., a no-backsliding standard.

The proposed N 2 O level was twice the average N 2 O level of primarily pre-2010 model year diesel engines as demonstrated in the ACES Study and in EPA's testing of two additional engines with selective catalytic reduction aftertreatement systems. [177] Manufacturers typically use design targets for NO X emission levels of about 50 percent of the standard, to account for in-use emissions deterioration and normal testing and production variability, and manufacturers are expected to utilize a similar approach for N 2 O emission compliance.

EPA sought comment about deterioration factors for N 2 O emissions. See 75 FR 74208. Industry stakeholders recommended that the agency define a DF of zero. While we believe it is also possible that N 2 O emissions will not deteriorate in use, very little data exist for aged engines and vehicles. Therefore, the value we are assigning is conservative, specifically additive DF of 0.02 g/bhp-hr. While the value is conservative, it is small enough to allow compliance for all engines except those very close to the standards. For engines too close to the standard to use the assigned DFs, the manufacturers would need to demonstrate via engineering analysis that deterioration is less than assigned DF.

EPA sought additional data on the level of the proposed N 2 O level of 0.05 g/bhp-hr. See 75 FR 74208. The agency received additional data of 2010 model year engines from the Engine Manufacturers Association. [178] The agencies reanalyzed a new data set, as shown in Table II-22, to derive the final N 2 O standard of 0.10 g/bhp-hr with a defined deterioration factor of 0.02 g/bhp-hr.

Table II-22—N 2 O Data Analysis Back to Top
Engine family Rated power (HP) Composite FTP cycle N 2 O result (g/bhp-hr)
EPA Data of 2007 Engine with SCR 0.042
EPA Data of 2010 Production Intent Engine 0.037
A 450 0.0181
A 600 0.0151
B 360 0.0326
C 380 0.0353
D 560 0.0433
D 455 0.0524
E 600 0.0437
F 500 0.0782
G 483 0.1127
H 385 0.0444
H 385 0.0301
H 385 0.0283
J 380 0.0317
Mean 0.043
2 * Mean 0.09

Engine emissions regulations do not currently require testing for N 2 O. The Mandatory GHG Reporting final rule requires reporting of N 2 O and requires that manufacturers either measure N 2 O or use a compliance statement based on good engineering judgment in lieu of direct N 2 O measurement (74 FR 56260, October 30, 2009). The light-duty GHG final rule allows manufacturers to provide a compliance statement based on good engineering judgment through the 2014 model year, but requires measurement beginning in 2015 model year (75 FR 25324, May 7, 2010). EPA is finalizing a consistent approach for heavy-duty engine manufacturers which allows them to delay direct measurement of N 2 O until the 2015 model year.

Manufacturers without the capability to measure N 2 O by the 2015 model year would need to acquire and install appropriate measurement equipment in response to this final program. EPA has established four separate N 2 O measurement methods, all of which are commercially available today. EPA expects that most manufacturers would use either photo-acoustic measurement equipment for stand-alone, existing FTIR instrumentation at a cost of $50,000 per unit or upgrade existing emission measurement systems with NDIR analyzers for $25,000 per test cell.

Overall, EPA believes that manufacturers of heavy-duty engines, both gasoline and diesel, would meet the final standard without implementing any new technologies, and beyond relatively small facilities costs for any company that still needs to acquire and install N 2 O measurement equipment, EPA does not project that manufacturers would incur significant costs associated with this final N 2 O standard.

EPA is not adopting any vehicle-level N 2 O standards for heavy-duty vocational vehicles and combination tractors. The N 2 O emissions would be controlled through the heavy-duty engine portion of the program. The only requirement of those vehicle manufacturers to comply with the N 2 O requirements is to install a certified engine.

(2) What is EPA's approach to controlling CH 4?

CH 4 is greenhouse gas with a GWP of 25. It accounts for about 0.03 percent of the greenhouse gases from heavy-duty trucks. [179]

EPA is finalizing a standard that would cap CH 4 emission levels, with the expectation that current heavy-duty vehicles and engines meeting the heavy-duty emission standards would not increase their levels as explained earlier due to robust current controls and manufacturer compliance margin targets. It would ensure that emissions would be addressed if in the future there are increases in the use of natural gas or any other alternative fuel. EPA believes that current heavy-duty emission standards, specifically the NMHC standards for both engine and chassis certified engines directly result in stringent CH 4 control. It is believed that the current emission control technologies used to meet the stringent NMHC standards achieve the maximum feasible reductions and that no additional technologies are recognized that would result in additional CH 4 reductions. The level of the standard would generally be achievable through normal emission control methods already required to meet heavy-duty emission standards for hydrocarbons and EPA is therefore not attributing any cost to this part of the final action. Since CH 4 is produced in gasoline and diesel engines similar to other hydrocarbon components, controls targeted at reducing overall NMHC levels generally also work at reducing CH 4 emissions. Therefore, for gasoline and diesel vehicles, the heavy-duty hydrocarbon standards will generally prevent increases in CH 4 emissions levels. CH 4 from heavy-duty vehicles is relatively low compared to other GHGs largely due to the high effectiveness of the current heavy-duty standards in controlling overall HC emissions.

EPA believes that this level for the standard would be met by current gasoline and diesel trucks and vans, and would prevent increases in future CH 4 emissions in the event that alternative fueled vehicles with high methane emissions, like some past dedicated compressed natural gas vehicles, become a significant part of the vehicle fleet. Currently EPA does not have separate CH 4 standards because, unlike other hydrocarbons, CH 4 does not contribute significantly to ozone formation. [180] However, CH 4 emissions levels in the gasoline and diesel heavy-duty truck fleet have nevertheless generally been controlled by the heavy-duty HC emission standards. Even so, without an emission standard for CH 4, future emission levels of CH 4 cannot be guaranteed to remain at current levels as vehicle technologies and fuels evolve.

In recent model years, a small number of heavy-duty trucks and engines were sold that were designed for dedicated use of natural gas. While emission control designs on these recent dedicated natural gas-fueled vehicles demonstrate CH 4 control can be as effective as on gasoline or diesel equivalent vehicles, natural gas-fueled vehicles have historically generated significantly higher CH 4 emissions than gasoline or diesel vehicles. This is because the fuel is predominantly methane, and most of the unburned fuel that escapes combustion without being oxidized by the catalyst is emitted as methane. However, even if these vehicles meet the heavy-duty hydrocarbon standard and appear to have effective CH 4 control by nature of the hydrocarbon controls, the heavy-duty standards do not require CH 4 control and therefore some natural gas vehicle manufacturers have invested very little effort into methane control. While the final CH 4 cap standard should not require any different emission control designs beyond what is already required to meet heavy-duty hydrocarbon standards on a dedicated natural gas vehicle (i.e., feedback controlled 3-way catalyst), the cap will ensure that systems provide robust control of methane much like a gasoline-fueled engine. We are not finalizing more stringent CH 4 standards because we believe that the controls used to meet current heavy-duty hydrocarbon standards should result in effective CH 4 control when properly implemented. Since CH 4 is already measured under the current heavy-duty emissions regulations (so that it may be subtracted to calculate NMHC), the final standard will not result in additional testing costs.

(a) Heavy-Duty Pickup Truck and Van CH 4 Standard

EPA is finalizing the proposed CH 4 emission standard of 0.05 g/mi as measured on the Light-duty FTP and HFET drive cycles, to apply beginning with model year 2014 for HD pickups and vans subject to the CO 2 standards. Similar to the CO 2 standard approach, the CH 4 emission level of a vehicle will be a composite of the Light-duty FTP and HFET cycles, with the same 55 percent city weighting and 45 percent highway weighting.

The level of the standard is approximately two times the average heavy-duty gasoline and diesel truck and van levels. [181] As with N 2 O, this standard level recognizes that manufacturers typically set emissions design targets with a compliance margin of approximately 50 percent of the standard. Thus, we believe that the standard should be met by current gasoline vehicles with no increase from today's CH 4 levels. Similarly, since current diesel vehicles generally have even lower CH 4 emissions than gasoline vehicles, we believe that diesels will also meet the standard with a larger compliance margin resulting in no change in today's CH 4 levels.

(b) Heavy-Duty Engine CH 4 Exhaust Emission Standard

EPA is adopting a heavy-duty engine CH 4 emission standard of 0.10 g/hp-hr with a defined deterioration factor of 0.02 g/bhp-hr as measured on the composite Heavy-duty FTP, to apply beginning in model year 2014 for diesel engines and in 2016 model year for gasoline engines. EPA is adopting a different CH 4 standard than proposed based on additional data submitted to the agency which better represents the full range of current diesel and gasoline engine performance. EPA is adopting CH 4 standards for gasoline engines that become effective in 2016 model year to align with the first year of the gasoline engine CO 2 standards. Without this alignment, manufacturers would not have any flexibility, such as CO 2 eq credits, in meeting the CH 4 cap and therefore would not be able to sell any engine with a CH 4 level above the standard. The final standard would cap CH 4 emissions at a level currently achieved by diesel and gasoline heavy-duty engines. The level of the standard would generally be achievable through normal emission control methods already required to meet 2007 emission standards for NMHC and EPA is therefore not attributing any cost to this part of this program (see 40 CFR 86.007-11).

The level of the final CH 4 standard is twice the average CH 4 emissions from gasoline engines from General Motors in addition to the four diesel engines in the ACES study. [182] As with N 2 O, this final level recognizes that manufacturers typically set emission design targets at about 50 percent of the standard. Thus, EPA believes the final standard would be met by current diesel and gasoline engines with little if any technological improvements. The agency believes a more stringent CH 4 standard is not necessary due to effective CH 4 controls in current heavy-duty technologies, since, as discussed above for N 2 O, EPA believes that the challenge of complying with the CO 2 standards should be the primary focus of the manufacturers.

CH 4 is measured under the current 2007 regulations so that it may be subtracted to calculate NMHC. Therefore EPA expects that the final standard would not result in additional testing costs.

EPA is not adopting any vehicle-level CH 4 standards for heavy-duty combination tractors or vocational vehicles in this final action. The CH 4 emissions will be controlled through the heavy-duty engine portion of the program. The only requirement of these truck manufacturers to comply with the CH 4 requirements is to install a certified engine.

(3) Use of CO 2 Credits

As proposed, if a manufacturer is unable to meet the N 2 O or CH 4 cap standards, the EPA program will allow the manufacturer to comply using CO 2 credits. In other words, a manufacturer could offset any N 2 O or CH 4 emissions above the standard by taking steps to further reduce CO 2. A manufacturer choosing this option would convert its measured N 2 O and CH 4 test results that are in excess of the applicable standards into CO 2 eq to determine the amount of CO 2 credits required. For example, a manufacturer would use 25 Mg of positive CO 2 credits to offset 1 Mg of negative CH 4 credits or use 298 Mg of positive CO 2 credits to offset 1 Mg of negative N 2 O credits. [183] By using the Global Warming Potential of N 2 O and CH 4, the approach recognizes the inter-correlation of these compounds in impacting global warming and is environmentally neutral for demonstrating compliance with the individual emissions caps. Because fuel conversion manufacturers certifying under 40 CFR part 85, subpart F do not participate in ABT programs, EPA is finalizing a compliance option for fuel conversion manufacturers to comply with the N 2 O and CH 4 standards that is similar to the credit program just described above. The compliance option will allow conversion manufacturers, on an individual engine family basis, to convert CO 2 overcompliance into CO 2 equivalents of N 2 0 and/or CH 4 that can be subtracted from the CH 4 and N 2 0 measured values to demonstrate compliance with CH 4 and/or N 2 0 standards. Other than in the limited case of N 2 O for model years 2014-16, we have not finalized similar provisions allowing overcompliance with the N 2 O or CH 4 standards to serve as a means to generate CO 2 credits because the CH 4 and N 2 O standards are cap standards representing levels that all but the worst vehicles should already be well below. Allowing credit generation against such cap standard would provide a windfall credit without any true GHG reduction.

The final NHTSA fuel consumption program will not use CO 2 eq, as suggested above. Measured performance to the NHTSA fuel consumption standards will be based on the measurement of CO 2 with no adjustment for N 2 O and/or CH 4. For manufacturers that use the EPA alternative CO 2 eq credit, compliance to the EPA CO 2 standard will not be directly equivalent to compliance with the NHTSA fuel consumption standard.

(4) Amendment to Light-Duty Vehicle N 2 O and CH 4 Standards

EPA also requested comment on revising a portion of the light-duty vehicle standards for N 2 O and CH 4. 75 FR at 74211. Specifically, EPA requested comments on two additional options for manufacturers to comply with N 2 O and CH 4 standards to provide additional near-term flexibility. EPA is finalizing one of those options, as discussed below.

For light-duty vehicles, as part of the MY 2012-2016 rulemaking, EPA finalized standards for N 2 O and CH 4 which take effect with MY 2012. 75 FR at 25421-24. Similar to the heavy-duty standards discussed in Section II.E above, the light-duty vehicle standards for N 2 O and CH 4 were established to cap emissions and to prevent future emissions increases, and were generally not expected to result in the application of new technologies or significant costs for the manufacturers for current vehicle designs. EPA also finalized an alternative CO 2 equivalent standard option, which manufacturers may choose to use in lieu of complying with the N 2 O and CH 4 cap standards. The CO 2 equivalent standard option allows manufacturers to fold all N 2 O and CH 4 emissions, on a CO 2 eq basis, along with CO 2 into their otherwise applicable CO 2 emissions standard level. For flexible fueled vehicles, the N 2 O and CH 4 standards must be met on both fuels (e.g., both gasoline and E-85).

After the light-duty standards were finalized, manufacturers raised concerns that for a few of the vehicle models in their existing fleet they were having difficulty meeting the N 2 O and/or CH 4 standards, especially in the early years of the program for a few of the vehicle models in their existing fleet. These standards could be problematic in the near term because there is little lead time to implement unplanned redesigns of vehicles to meet the standards. In such cases, manufacturers may need to either drop vehicle models from their fleet or to comply using the CO 2 equivalent alternative. On a CO 2 eq basis, folding in all N 2 O and CH 4 emissions would add 3-4 g/mile or more to a manufacturer's overall fleet-average CO 2 emissions level because the alternative standard must be used for the entire fleet, not just for the problem vehicles. [184] See 75 FR at 74211. This could be especially challenging in the early years of the program for manufacturers with little compliance margin because there is very limited lead time to develop strategies to address these additional emissions. As stated at proposal, EPA believed this posed a legitimate issue of sufficiency of lead time in the short term, as well as an issue of cost, since EPA assumed that the N 2 O and CH 4 standards would not result in significant costs for existing vehicles. Id. However, EPA expected that manufacturers would be able to make technology changes (e.g., calibration or catalyst changes) to the few vehicle models not currently meeting the N 2 O and/or CH 4 standards in the course of their planned vehicle redesign schedules in order to meet the standards.

Because EPA intended for these standards to be caps with little anticipated near-term impact on manufacturer's current product lines, EPA requested comment in the heavy-duty vehicle and engine proposal on two approaches to provide additional flexibilities in the light-duty vehicle program for meeting the N 2 O and CH 4 standards. 75 FR at 74211. EPA requested comments on the option of allowing manufacturers to use the CO 2 equivalent approach for one pollutant but not the other for their fleet—that is, allowing a manufacturer to fold in either CH 4 or N 2 O as part of the CO 2-equivalent standard. For example, if a manufacturer is having trouble complying with the CH 4 standard but not the N 2 O standard, the manufacturer could use the CO 2 equivalent option including CH 4, but choose to comply separately with the applicable N 2 O cap standard.

EPA also requested comments on an alternative approach of allowing manufacturers to use CO 2 credits, on a CO 2 equivalent basis, to offset N 2 O and CH 4 emissions above the applicable standard. This is similar to the approach proposed and being finalized for heavy-duty vehicles as discussed above in Section II.E. EPA requested comments on allowing the additional flexibility in the light-duty program for MYs 2012-2014 to help manufacturers address any near-term issues that they may have with the N 2 O and CH 4 standards.

Commenters providing comment on this issue supported additional flexibility for manufacturers, and manufacturers specifically supported the heavy-duty vehicle approach of allowing CO 2 credits on a CO 2 equivalent basis to be used to meet the CH 4 and N 2 O standards. The Alliance of Automobile Manufacturers and the American Automotive Policy Council commented that the proposed heavy-duty approach represented a significant improvement over the approach adopted for light-duty vehicles. Manufacturers support de-linking N 2 O and CH 4, and commented that the formation of the pollutants do not necessarily trend together. Manufacturers also commented that a deficit against the N 2 O or CH 4 cap would be required to be covered with CO 2 credits for that model, but the approach does not “punish” manufacturers for using a specific technology (which could provide CO 2 benefits, e.g., diesel, CNG, etc.) by requiring manufacturers to use the CO 2-equivalent approach for their entire fleet. The Natural Gas Vehicle Interests also supported allowing the use of CO 2 credits on a CO 2-equivalent basis for compliance with CH 4 standards and urged providing this type of flexibility on a permanent basis. The Institute for Policy Integrity also submitted comments supportive of providing additional flexibility to manufacturers as long as it does not undermine standard stringency. This commenter was supportive of either approach discussed at proposal. [185]

Manufacturers supported not only adopting the aspects of the heavy-duty approach noted above, but the entire heavy-duty vehicle approach, including two aspects of the program not contemplated in EPA's request for comments. First, manufacturers commented that EPA incorrectly characterizes the light-duty vehicle issues with CH 4 and N 2 O as short-term or early lead time issues. For the reasons discussed above, manufacturers believe the changes should be made permanent, for the entire 2012-2016 light-duty rulemaking period and, indeed, in any subsequent rules for the light-duty vehicle sector. Second, manufacturers commented that N 2 O and CH 4 should be measured on the combined 55/45 weighting of the FTP and highway cycles, respectively, as these cycles are the yardstick for fuel economy and CO 2 measurement. Manufacturers commented that there should not be a disconnect between the light-duty and heavy-duty vehicle programs.

EPA continues to believe that it is appropriate to provide additional flexibility to manufacturers to meet the N 2 O and CH 4 standards. EPA is thus finalizing provisions allowing manufacturers to use CO 2 credits, on a CO 2-equivalent basis, to meet the N 2 O and CH 4 standards, which is consistent with many commenters' preferred approach. Manufacturers will have the option of using CO 2 credits to meet N 2 O and CH 4 standards on a test group basis as needed for MYs 2012-2016. Because fuel conversion manufacturers certifying under 40 CFR part 85, subpart F do not participate in ABT programs, EPA is finalizing a compliance option for fuel conversion manufacturers to comply with the N 2 O and CH 4 standards similar to the credit option just described above. The compliance option will allow conversion manufacturers, on an individual test group basis, to convert CO 2 overcompliance into CO 2 equivalents of N 2 O and/or CH 4 that can be subtracted from the CH 4 and N 2 O measured values to demonstrate compliance with CH 4 and/or N 2 O standards.

In EPA's request for comments, EPA discussed the new flexibility as being needed to address lead time issues for MYs 2012-2014. EPA understands that manufacturers are now making technology decisions for beyond MY 2014 and that some technologies such as FFVs may have difficulty meeting the CH 4 and N 2 O standards, presenting manufacturers with difficult decisions of absorbing the 3-4 g/mile CO 2-equivalent emissions fleet wide, making significant investments in existing vehicle technologies, or curtailing the use of certain technologies. [186] The CH 4 standard, in particular, could prove challenging for FFVs because exhaust temperatures are lower on E-85 and CH 4 is more difficult to convert over the catalyst. EPA's initial estimate that these issues could be resolved without disrupting product plans by MY 2015 appears to be overly optimistic, and therefore EPA is extending the flexibility through model year 2016. This change helps ensure that the CH 4 and N 2 O standards will not be an obstacle for the use of FFVs or other technologies in this timeframe, and at the same time, assure that overall fleet average GHG emissions will remain at the same level as under the main standards.

In response to comments from manufacturers and from the Natural Gas Vehicle Interests that the changes to the program make sense and should be made on a permanent basis (i.e. for model years after 2016), EPA is extending this flexibility through MY 2016 as discussed above, but we believe it is premature to decide here whether or not these changes should be permanent. EPA may consider this issue further in the context of new standards for MYs 2017-2025 in the planned future light-duty vehicle rulemaking. With regard to comments on changing the test procedures over which N 2 O and CH 4 emissions are measured to determine compliance with the standards, the level of the standards and the test procedures go hand-in-hand and must be considered together. Weighting the highway test result with the city test result in the emissions measurement would in most cases reduce the overall emissions levels for determining compliance with the standards, and would thereby, in effect make the standards less stringent. This appears to be inappropriate. In addition, EPA did not request comments on changing the level of the N 2 O and CH 4 standards or the test procedures and it is inappropriate to amend the standards for that reason as well.

(5) EPA's Final Standards for Direct Emissions From Air Conditioning

Air conditioning systems contribute to GHG emissions in two ways—direct emissions through refrigerant leakage and indirect exhaust emissions due to the extra load on the vehicle's engine to provide power to the air conditioning system. HFC refrigerants, which are powerful GHG pollutants, can leak from the A/C system. [187] This includes the direct leakage of refrigerant as well as the subsequent leakage associated with maintenance and servicing, and with disposal at the end of the vehicle's life. [188] The most commonly used refrigerant in automotive applications—R134a, has a high GWP of 1430. [189] Due to the high GWP of R134a, a small leakage of the refrigerant has a much greater global warming impact than a similar amount of emissions of CO 2 or other mobile source GHGs.

Heavy-duty air conditioning systems today are similar to those used in light-duty applications. However, differences may exist in terms of cooling capacity (such that sleeper cabs have larger cabin volumes than day cabs), system layout (such as the number of evaporators), and the durability requirements due to longer vehicle life. However, the component technologies and costs to reduce direct HFC emissions are similar between the two types of vehicles.

The quantity of GHG refrigerant emissions from heavy-duty trucks relative to the CO 2 emissions from driving the vehicle and moving freight is very small. Therefore, a credit approach is not appropriate for this segment of vehicles because the value of the credit is too small to provide sufficient incentive to utilize feasible and cost-effective air conditioning leakage improvements. For the same reason, including air conditioning leakage improvements within the main standard would in many instances result in lost control opportunities. Therefore, EPA is finalizing the proposed requirement that vehicle manufacturers meet a low leakage requirement for all air conditioning systems installed in 2014 model year and later trucks, with one exception. The agency is not finalizing leakage standards for Class 2b-8 Vocational Vehicles at this time due to the complexity in the build process and the potential for different entities besides the chassis manufacturer to be involved in the air conditioning system production and installation, with consequent difficulties in developing a regulatory system.

For air conditioning systems with a refrigerant capacity greater than 733 grams, EPA is finalizing a leakage standard which is a “percent refrigerant leakage per year” to assure that high-quality, low-leakage components are used in each air conditioning system design. The agency believes that a single “gram of refrigerant leakage per year” would not fairly address the variety of air conditioning system designs and layouts found in the heavy-duty truck sector. EPA is finalizing a standard of 1.50 percent leakage per year for heavy-duty pickup trucks and vans and Class 7 and 8 tractors. The final standard was derived from the vehicles with the largest system refrigerant capacity based on the Minnesota GHG Reporting database. [190] The average percent leakage per year of the 2010 model year vehicles is 2.7 percent. This final level of reduction is roughly comparable to that necessary to generate credits under the light-duty vehicle program. See 75 FR 25426-25427. Since refrigerant leakage past the compressor shaft seal is the dominant source of leakage in belt-driven air conditioning systems, the agency recognizes that a single “percent refrigerant leakage per year” is not feasible for systems with a refrigerant capacity of 733 grams or lower, as the minimum feasible leakage rate does not continue to drop as the capacity or size of the air conditioning system is reduced. The fixed leakage from the compressor seal and other system devices results in a minimum feasible yearly leakage rate, and further reductions in refrigerant capacity (the `denominator' in the percent refrigerant leakage calculation) will result in a system which cannot meet the 1.50 percent leakage per year standard. EPA does not believe that leakage reducing technologies are available at this time which would allow lower capacity systems to meet the percent per year standard, so we are finalizing a maximum gram per year leakage standard of 11.0 grams per year for air conditioning systems with a refrigerant capacity of 733 grams or lower. EPA defined the standard, as well as the refrigerant capacity threshold, by examining the State of Minnesota GHG Reporting Database for the yearly leakage rate from 2010 and 2011 model year pickup trucks. In the Minnesota data, the average leak rate for the pickup truck category (16 unique model and refrigerant capacity combinations) was 13.3 grams per year, with an average capacity of 654 grams, resulting in an average percent refrigerant leakage per year of 2.0 percent. 4 of the 16 model/capacity combinations in the reporting data achieved a leak rate 11.0 grams per year or lower, and this was chosen as the maximum yearly leak rate, as several manufacturers have demonstrated that this level of yearly leakage is feasible. To avoid a discontinuity between the “percent leakage” and “leak rate” standards—where one approach would be more or less stringent, depending on the refrigerant capacity—a refrigerant capacity of 733 grams was chosen as a threshold capacity, below which, the leak rate approach can be used. EPA believes this approach of having a leak rate standard for lower capacity systems and a percent leakage per year standard for higher capacity systems will result in reduced refrigerant emissions from all air conditioning systems, while still allowing manufacturers the ability to produce low-leak, lower capacity systems in vehicles which require them.

Manufacturers can choose to reduce A/C leakage emissions in two ways. First, they can utilize leak-tight components. Second, manufacturers can largely eliminate the global warming impact of leakage emissions by adopting systems that use an alternative, low-Global Warming Potential (GWP) refrigerant. One alternative refrigerant, HFO-1234yf, with a GWP of 4, has been approved for use in light-duty passenger vehicles under EPA's Significant New Alternatives Program (SNAP). While the scope of this SNAP approval does not include heavy-duty highway vehicles, we expect that those interested in using this refrigerant in other sectors will petition EPA for broader approval of its use in all mobile air conditioning systems. In addition, the EPA is currently acting on a petition to de-list R-134a as an acceptable refrigerant for new, light-duty passenger vehicles. The time frame and scale of R-134a de-listing is yet to be determined, but any phase-down of R-134a use will likely take place after this rulemaking is in effect. Given that HFO-1234yf is yet to be approved for heavy-duty vehicles, and that the time frame for the de-listing of R-134a is not known, EPA believes that a leakage standard for heavy-duty vehicles is still appropriate. If future heavy-duty vehicles adopt refrigerants other than R-134a, the calculated refrigerant leak rate can be adjusted by multiplying the leak rate by the ratio of the GWP of the new refrigerant divided by the GWP of the old refrigerant (e.g. for HFO-1234yf replacing R-134a, the calculated leak rate would be multiplied by 0.0028, or 4 divided by 1430).

EPA believes that reducing A/C system leakage is both highly cost-effective and technologically feasible. The availability of low leakage components is being driven by the air conditioning program in the light-duty GHG rule which apply to 2012 model year and later vehicles. The cooperative industry and government Improved Mobile Air Conditioning program has demonstrated that new-vehicle leakage emissions can be reduced by 50 percent by reducing the number and improving the quality of the components, fittings, seals, and hoses of the A/C system. [191] All of these technologies are already in commercial use and exist on some of today's systems, and EPA does not anticipate any significant improvements in sealing technologies for model years beyond 2014. However, EPA has recognized some manufacturers utilize an improved manufacturing process for air conditioning systems, where a helium leak test is performed on 100 percent of all o-ring fittings and connections after final assembly. By leak testing each fitting, the manufacturer or supplier is verifying the o-ring is not damaged during assembly (which is the primary source of leakage from o-ring fittings), and when calculating the yearly leak rate for a system, EPA will allow a relative emission value equivalent to a `seal washer' can be used in place of the value normally used for an o-ring fitting, when 100 percent helium leak testing is performed on those fittings. While further updates to the SAE J2727 standard may be forthcoming (to address new materials and measurement methods for permeation through hoses), EPA believes it is appropriate to include the helium leak test update to the leakage calculation method at this time.

Consistent with the light-duty 2012-2016 MY vehicle rule, we are estimating costs for leakage control at $18 (2008$) in direct manufacturing costs. Including a low complexity indirect cost multiplier (ICM) of 1.14 results in costs of $21 in the 2014 model year. A/C control technology is considered to be on the flat portion of the learning curve, so costs in the 2017 model year will be $19. These costs are applied to all heavy-duty pickups and vans, and to all combination tractors. EPA views these costs as minimal and the reductions of potent GHGs to be easily feasible and reasonable in the lead times provided by the final rules.

EPA is requiring that manufacturers demonstrate improvements in their A/C system designs and components through a design-based method. The method for calculating A/C leakage is based closely on an industry-consensus leakage scoring method, described below. This leakage scoring method is correlated to experimentally-measured leakage rates from a number of vehicles using the different available A/C components. Under the final approach, manufacturers will choose from a menu of A/C equipment and components used in their vehicles in order to establish leakage scores, which will characterize their A/C system leakage performance and calculate the percent leakage per year as this score divided by the system refrigerant capacity.

Consistent with the light-duty rule, EPA is finalizing a requirement that a manufacturer will compare the components of its A/C system with a set of leakage-reduction technologies and actions that is based closely on that being developed through the Improved Mobile Air Conditioning program and SAE International (as SAE Surface Vehicle Standard J2727, “HFC-134a, Mobile Air Conditioning System Refrigerant Emission Chart,” August 2008 version). See generally 75 FR 25426. The SAE J2727 approach was developed from laboratory testing of a variety of A/C related components, and EPA believes that the J2727 leakage scoring system generally represents a reasonable correlation with average real-world leakage in new vehicles. Like the cooperative industry-government program, our final approach will associate each component with a specific leakage rate in grams per year that is identical to the values in J2727 and then sum together the component leakage values to develop the total A/C system leakage. However, in the heavy-duty vehicle program, the total A/C leakage score will then be divided by the value of the total refrigerant system capacity to develop a percent leakage per year. EPA believes that the design-based approach will result in estimates of likely leakage emissions reductions that will be comparable to those that would eventually result from performance-based testing.

EPA is not specifying a specific in-use standard for leakage, as neither test procedures nor facilities exist to measure refrigerant leakage from a vehicle's air conditioning system. However, consistent with the light-duty rule, where we require that manufacturers attest to the durability of components and systems used to meet the CO 2 standards (see 75 FR 25689), we will require that manufacturers of heavy-duty vehicles attest to the durability of these systems, and provide an engineering analysis which demonstrates component and system durability.

(6) Indirect Emissions From Air Conditioning

In addition to direct emissions from refrigerant leakage, air conditioning systems also create indirect exhaust emissions due to the extra load on the vehicle's engine to provide power to the air conditioning system. These indirect emissions are in the form of the additional CO 2 emitted from the engine when A/C is being used due to the added loads. Unlike direct emissions which tend to be a set annual leak rate not directly tied to usage, indirect emissions are fully a function of A/C usage.

These indirect CO 2 emissions are associated with air conditioner efficiency, since air conditioners create load on the engine. See 74 FR 49529. However, the agencies are not setting air conditioning efficiency standards for vocational vehicles, combination tractors, or heavy-duty pickup trucks and vans. The CO 2 emissions due to air conditioning systems in these heavy-duty vehicles are minimal compared to their overall emissions of CO 2. For example, EPA conducted modeling of a Class 8 sleeper cab using the GEM to evaluate the impact of air conditioning and found that it leads to approximately 1 gram of CO 2/ton-mile. Therefore, a projected 24 percent improvement of the air conditioning system (the level projected in the light-duty GHG rulemaking), would only reduce CO 2 emissions by less than 0.3 g CO 2/ton-mile, or approximately 0.3 percent of the baseline Class 8 sleeper cab CO 2 emissions.

(7) Ethanol-Fueled and Electric Vehicles

Current EPA emissions control regulations explicitly apply to heavy-duty engines and vehicles fueled by gasoline, methanol, natural gas and liquefied petroleum gas. For multi-fueled vehicles they call for compliance with requirements established for each consumed fuel. This contrasts with EPA's light-duty vehicle regulations that apply to all vehicles generally, regardless of fuel type. As we proposed, we are revising the heavy-duty vehicle and engine regulations to make them consistent with the light-duty vehicle approach, applying standards for all regulated criteria pollutants and GHGs regardless of fuel type, including application to all-electric vehicles (EVs). This provision will take effect in the 2014 model year, and be optional for manufacturers in earlier model years. However, to satisfy the CAA section 202(a)(3) lead time constraints, the provision will remain optional for all criteria pollutants through the 2015 model year. Commenters did not oppose this change in EPA regulations.

This change primarily affects manufacturers of ethanol-fueled vehicles (designed to operate on fuels containing at least 50 percent ethanol) and EVs. Flex-fueled vehicles (FFVs) designed to run on both gasoline and fuel blends with high ethanol content will also be impacted, as they will need to comply with requirements for operation both on gasoline and ethanol.

The regulatory requirements we are finalizing today for certification on ethanol follow those already established for methanol, such as certification to NMHC equivalent standards and waiver of certain requirements. We expect testing to be done using the same E85 test fuel as is used today for light-duty vehicle testing, an 85/15 blend of commercially-available ethanol and gasoline vehicle test fuel. EV certification will also follow light-duty precedents, primarily calling on manufacturers to exercise good engineering judgment in applying the regulatory requirements, but will not be allowed to generate NO X or PM credits.

This provision is not expected to result in any significant added burden or cost. It is already the practice of HD FFV manufacturers to voluntarily conduct emissions testing for these vehicles on E85 and submit the results as part of their certification application, along with gasoline test fuel results. No changes in certification fees are being set in connection with this provision. We expect that there will be strong incentives for any manufacturer seeking to market these vehicles to also want them to be certified: (1) Uncertified vehicles carry a disincentive to potential purchasers who typically have the benefit to the environment as one of their reasons for considering alternative fuels, (2) uncertified vehicles are not eligible for the substantial credits they could likely otherwise generate, (3) EVs have no tailpipe or evaporative emissions and thus need no added hardware to put them in a certifiable configuration, and (4) emissions controls for gasoline vehicles and FFVs are also effective on dedicated ethanol-fueled vehicles, and thus costly development programs and specialized components will not be needed; in fact the highly integrated nature of modern automotive products make the emission control systems essential to reliable vehicle performance.

Regarding technological feasibility, as mentioned above, HD FFV manufacturers already test on E85 and the resulting data shows that they can meet emissions standards on this fuel. Furthermore, there is a substantial body of certification data on light-duty FFVs (for which testing on ethanol is already a requirement), showing existing emission control technology is capable of meeting even the more stringent Tier 2 standards in place for light-duty vehicles.

(8) Correction to 40 CFR 1033.625

In a 2008 final rule that set new locomotive and marine engine standards, EPA adopted a provision allowing manufacturers to use a limited number of nonroad engines to power switch locomotives provided, among other things, that “the engines were certified to standards that are numerically lower than the applicable locomotive standards of this part (1033).” (40 CFR 1033.625(a)). The goal of this provision is to encourage the replacement of aging, high-emitting switch locomotives with new switch locomotives having very low emissions of PM, NO X, and hydrocarbons. However, this provision neglected to consider the fact that preexisting nonroad engine emission standards for CO were set at levels that were slightly numerically higher than those for locomotives. The applicable switch locomotive CO standard of part 1033 is 3.2 g/kW-hr (2.4 g/hp-hr), while the applicable nonroad engine CO standard is 3.5 g/kW-hr (2.6 g/hp-hr). This is the case even for the cleanest final Tier 4 nonroad engines that will phase in starting in 2014. Thus, nonroad engines cannot be certified to CO standards that are numerically lower than the applicable locomotive standards, and the nonroad engine provision is rendered practically unusable. This matter was brought to EPA's attention by affected engine manufacturers. [192]

As indicated above, EPA believes that allowing certification of new switch locomotive engines to nonroad engine standards will greatly reduce emissions from switch locomotives, and EPA does not believe the slight difference in CO standards should prevent this environmentally beneficial program. EPA is therefore adopting a corrective technical amendment in part 1033. The regulation is being amended at § 1033.625(a)(2) to add the following italicized text: “The engines were certified to PM, NO X, and hydrocarbon standards that are numerically lower than the applicable locomotive standards of this part.” This change is a straightforward correction to restore the intended usability of the provision and is not expected to have adverse environmental impacts, as nonroad engines have CO emissions that are typically well below both the nonroad and locomotive emissions standards.

(9) Corrections to 40 CFR Part 600

EPA adopted changes to fuel economy labeling requirements on July 6, 2011 (76 FR 39478). We are making the following corrections to these regulations in 40 CFR part 600:

  • We adopted a requirement to use the specifications of SAE J1711 for fuel economy testing related to hybrid-electric vehicles. In this final rule, we are extending that requirement to the calculation provisions in § 600.114-12. This change was inadvertently omitted from the earlier final rule.
  • We are correcting an equation in § 600.116-12.
  • We are removing text describing label content that differs from the sample labels that were published with the final rule. The sample labels properly characterize the intended label content.

(10) Definition of Urban Bus

EPA is adding a new section 86.012-2 to revise the definition of “urban bus.” The new definition will treat engines used in urban buses the same as engines used in any other HD vehicle application, relying on the definitions of primary intended service class for defining which standards and useful life apply for bus engines. This change is necessary to allow for installation of engines other than HHDDE for hybrid bus applications.

III. Feasibility Assessments and Conclusions Back to Top

In this section, NHTSA and EPA discuss several aspects of our joint technical analyses. These analyses are common to the development of each agency's final standards. Specifically we discuss: the development of the baseline used by each agency for assessing costs, benefits, and other impacts of the standards, the technologies the agencies evaluated and their costs and effectiveness, and the development of the final standards based on application of technology in light of the attribute based distinctions and related compliance measurement procedures. We also discuss the agencies' consideration of standards that are either more or less stringent than those adopted.

This program is based on the need to obtain significant oil savings and GHG emissions reductions from the transportation sector, and the recognition that there are appropriate and cost-effective technologies to achieve such reductions feasibly in the model years of this program. The decision on what standard to set is guided by each agency's statutory requirements, and is largely based on the need for reductions, the effectiveness of the emissions control technology, the cost and other impacts of implementing the technology, and the lead time needed for manufacturers to employ the control technology. The availability of technology to achieve reductions and the cost and other aspects of this technology are therefore a central focus of this final rulemaking.

CBD submitted several comments on whether NHTSA had met EISA's mandate to set standards “designed to achieve the maximum feasible improvement” and, to that end, appropriately considered feasible technologies in setting the stringency level. CBD stated that the proposed rule had been improperly limited to currently available technology, and that none of the alternatives contained all of the available technology, which it argued violated EISA and the CAA. CBD also stated that the phase-in schedule violated the technology-forcing intention of EISA, and that the agencies misperceived their statutory mandates, arguing that the agencies are required to force technological innovation through aggressive standards.

As demonstrated in the standard-specific discussions later in this section of the preamble, the standards adopted in the final program are consistent with section 202(a) of the CAA and section 32902(k)(2) of EISA. With respect to the EPA rules, we note at the outset, that CBD's premise that EPA must adopt “technology-forcing” standards for heavy-duty vehicles and engines is wrong. A technology-forcing standard is one that is to be based on standards which will be available, rather than technology which is presently available. NRDC v. Thomas, 805 F. 2d 410, 429 (DC Cir. 1986). Clean Air Act provisions requiring “the greatest degree of emission reduction achievable through the application of technology which the Administrator determines will be available” are technology-forcing. See e.g., CAA sections 202(a)(3)(1); [193] 213(a)(3). Section 202(a)(1) standards are technology-based, but not technology-forcing, requiring EPA to issue standards for a vehicle's useful life “after providing such period as the Administrator finds necessary to permit the development and application of the requisite technology, giving appropriate consideration to the cost of compliance within such period.” See NACAA v. EPA, 489 F. 3d 1221, 1230 (DC Cir. 2007) upholding EPA's interpretation of similar language in CAA section 231(a) as providing even greater leeway to weigh the statutory factors than if the provision were technology-forcing. See generally 74 FR at 49464-465 (Sept. 28. 2009); 75 FR at 74171.

Section 202(a)(1) of course allows EPA to consider application of technologies which will be available as well as those presently available, id., and EPA exercised that discretion here. For example, as shown below, the agencies carefully considered application of hybrid technologies and bottoming cycle technologies for a number of the standards. Thus, the critical issue is whether EPA's choice of technology penetration on which the standards are premised is reasonable considering the statutory factors, the key ones being technology feasibility, technology availability in the 2014-2018 model years (i.e., adequacy of lead time), and technology cost and cost-effectiveness. EPA has considerable discretion to weigh these factors in a reasonable manner (even for provisions which are explicitly technology-forcing, see Sierra Club v. EPA, 325 F. 3d 374, 378 (DC Cir. 2003)), and has done so here.

With respect to EISA, 49 U.S.C. section 32902(k)(2) directs NHTSA to “determine in a rulemaking proceeding how to implement a commercial medium- and heavy-duty on-highway vehicle and work truck fuel efficiency improvement program designed to achieve the maximum feasible improvement,” and “adopt and implement appropriate test methods, measurement metrics, fuel economy standards, and compliance and enforcement protocols that are appropriate, cost-effective, and technologically feasible for commercial medium- and heavy-duty on-highway vehicles and work trucks” NHTSA recognizes that Congress intended EPCA (and by extension, EISA, which amended it) to be technology-forcing. See Center for Auto Safety v. National Highway Traffic Safety Admin., 793 F.2d 1322, 1339 (DC Cir. 1986). However, NHTSA believes it is important to distinguish between setting “maximum feasible” standards, as EPCA/EISA requires, and “maximum technologically feasible” standards, as CBD would have NHTSA do. The agency must weigh all of the statutory factors in setting fuel efficiency standards, and therefore may not weigh one statutory factor in isolation of others.

Neither EPCA nor EISA define “maximum feasible” in the context of setting fuel efficiency or fuel economy standards. Instead, NHTSA is directed to consider and meet three factors when determining what the maximum feasible standards are—“appropriateness, cost-effectiveness, and technological feasibility.” 32902(k)(2). These factors modify “feasible” in the context of the MD/HD rules beyond a plain meaning of “capable of being done.”See Center for Biological Diversity v. National Highway Traffic Safety Admin., 538 F.3d 1172, 1194 (9th Cir. 2008). With respect to the setting of standards for light-duty vehicles, EPCA/EISA “gives NHTSA discretion to decide how to balance the statutory factors—as long as NHTSA's balancing does not undermine the fundamental purpose of EPCA: energy conservation.”Id. at 1195. Where Congress has not directly spoken to a potential issue related to such a balancing, NHTSA's interpretation must be a “reasonable accommodation of conflicting policies * * * committed to the agency's care by the statute.”Id. (discussing consideration of consumer demand) (internal citations omitted). In the context of the agency's light-duty vehicle authority, it was determined that Congress delegated the process for setting the maximum feasible standard to NHTSA with broad guidelines concerning the factors that the agency must consider. Id. (internal citations omitted) (emphasis in original). We believe that the same conclusion should be drawn about the statutory provisions governing the agency's setting of standards for heavy-duty vehicles. Those provisions prescribe statutory factors commensurate to, and equally broad as, those prescribed for light-duty. Thus, NHTSA believes that it is firmly within our discretion to weigh and balance the factors laid out in 32902(k) in a way that is technology-forcing, as evidenced by these standards promulgated in this final action, but not in a way that requires the application of technology which will not be available in the lead time provided by the rules, or which is not cost-effective, or is cost-prohibitive, as CBD evidently deems mandated.

As detailed below for each regulatory category, NHTSA has considered the appropriateness, cost-effectiveness, and technological feasibility of the standards in designing a program to achieve the maximum feasible fuel efficiency improvement. It believes that each of those criteria is met.

As described in Section I. F. (2) above, the final standards will remain in effect indefinitely at their 2018 or 2019 levels, unless and until the standards are revised. CBD maintained that this is a per se violation of EISA, arguing that, by definition, standards which are not updated continually and regularly cannot be considered maximum feasible. NHTSA would like to clarify that the NPRM specified that the standards would remain indefinitely “until amended by a future rulemaking action.” NPRM at 74172. Further, as noted above, NHTSA has broad discretion to determine the maximum feasible standards. Unlike § 32902(b)(3)(B), which applies to automobiles regulated under light-duty CAFE, § 32902(k) does not specify a maximum number of years that fuel economy standards for heavy-duty vehicles will be in place. Consistent with its broad authority to define maximum feasible standards, NHTSA interprets its authority as including the discretion to define expiration periods where Congress has not otherwise specified. This is particularly appropriate for the heavy-duty sector, where fuel efficiency regulation is unprecedented. NHTSA believes that it would be unwise to set an expiration period for this first rulemaking absent both Congressional direction and a known compelling reason for setting a specific date.

NHTSA believes that the phase-in schedules provide an appropriate balance between the technology-forcing purpose of the statute and EISA-mandated considerations of economic practicability. NHTSA recognizes, as noted in the case above, that balancing each statutory factor in order to set the maximum feasible standards means that the agency must engage in a “reasonable accommodation of conflicting policies.”See 538 F.3d at 1195, supra. Here, the agency has determined that the phase-in schedules are one such reasonable accommodation.

Navistar commented generally that the proposed rule was not technologically feasible, stating that the proposed standards assume technologies which are not in production for all manufacturers. This is not the test for technical feasibility. Under the Clean Air Act, EPA needs only to outline a technical path toward compliance with a standard, giving plausible reasons for its belief that technology will either be developed or applied in the requisite period. NRDC v. EPA, 655 F. 2d 318, 333-34 (DC Cir. 1981). EPA has done so here with respect to the alternative engine standards of particular concern to Navistar. [194] Similarly, NHTSA has previously interpreted “technological feasibility” to mean “whether a particular method of improving fuel economy can be available for commercial application in the model year for which a standard is being established.” 74 FR 14196, 14216. NHTSA has further clarified that the consideration of technological feasibility “does not mean that the technology must be available or in use when a standard is proposed or issued.”Center for Auto Safety v. National Highway Traffic Safety Admin., 793 F.2d 1322, 1325 n12 (DC Cir. 1986), quoting 42 FR 63, 184, 63, 188 (1977).

Consistent with these previous interpretations, NHTSA believes that a technology does not necessarily need to be currently available or in use for all regulated parties to be “technologically feasible” for this program, as long as it is reasonable to expect, based on the evidence before the agency, that the technology will be available in the model year in which the relevant standard takes effect. The agencies provide multiple technology pathways for compliance with a standard, allowing each manufacturer to develop technologies which fit their current production and research, and the standards are based on fleet penetration rates of those technologies. As discussed below, it is reasonable to assume that all the technologies on whose performance the standards are premised will be available over the period the standards are in effect.

The Institute for Policy Integrity (IPI) commented that the agencies should increase the scope and stringency of the final rule to the point at which net benefits would be maximized, citing Executive Orders 12866 and 13563. EOs 12866 and 13563 instruct agencies, to the extent permitted by law, to select, among other things, the regulatory approaches which maximize net benefits. NHTSA agrees with IPI about the applicability of these EOs and has made every effort to incorporate their guidance in drafting this rule.

Though IPI agreed that the proposed rule was cost-benefit justified, IPI further stated that the agencies must implement an alternative that provides the maximum net benefits. The agencies believe that standards that maximized net benefits would be beyond the point of technological feasibility for this first phase of the HD National Program. The standards already require the maximum feasible fuel efficiency improvements for the HD fleet in the 2014-2018 time frame. Thus, even though, the final standards are highly cost-effective, and standards that maximized net benefits would likely be more stringent than those being promulgated in this final action, NHTSA believes that standards that maximized net benefits would not be appropriate or technologically feasible in the rulemaking time frame. The Executive Orders cited by IPI cannot and do not require an agency to select a regulatory alternative that is inconsistent with its statutory obligations. Thus, the standards adopted in the final rules are consistent with the agencies' respective statutory authorities, and are not established at levels which are infeasible or cost-ineffective.

Here, the focus of the standards is on applying fuel efficiency and emissions control technology to reduce fuel consumption, CO 2 and other greenhouse gases. Vehicles combust fuel to generate power that is used to perform two basic functions: (1) Transport the truck and its payload, and (2) operate various accessories during the operation of the truck such as the PTO units. Engine-based technology can reduce fuel consumption and CO 2 emissions by improving engine efficiency, which increases the amount of power produced per unit of fuel consumed. Vehicle-based technology can reduce fuel consumption and CO 2 emissions by increasing the vehicle efficiency, which reduces the amount of power demanded from the engine to perform the truck's primary functions.

Our technical work has therefore focused on both engine efficiency improvements and vehicle efficiency improvements. In addition to fuel delivery, combustion, and aftertreatment technology, any aspect of the truck that affects the need for the engine to produce power must also be considered. For example, the drag due to aerodynamics and the resistance of the tires to rolling both have major impacts on the amount of power demanded of the engine while operating the vehicle.

The large number of possible technologies to consider and the breadth of vehicle systems that are affected mean that consideration of the manufacturer's design and production process plays a major role in developing the final standards. Engine and vehicle manufacturers typically develop many different models based on a limited number of platforms. The platform typically consists of a common engine or truck model architecture. For example, a common engine platform may contain the same configuration (such as inline), number of cylinders, valvetrain architecture (such as overhead valve), cylinder head design, piston design, among other attributes. An engine platform may have different calibrations, such as different power ratings, and different aftertreatment control strategies, such as exhaust gas recirculation (EGR) or selective catalytic reduction (SCR). On the other hand, a common vehicle platform has different meanings depending on the market. In the heavy-duty pickup truck market, each truck manufacturer usually has only a single pickup truck platform (for example the F series by Ford) with common chassis designs and shared body panels, but with variations on load capacity of the axles, the cab configuration, tire offerings, and powertrain options. Lastly, the combination tractor market has several different platforms and the trucks within each platform (such as LoneStar by Navistar) have less commonality. Tractor manufacturers will offer several different options for bumpers, mirrors, aerodynamic fairing, wheels, and tires, among others. However, some areas such as the overall basic aerodynamic design (such as the grill, hood, windshield, and doors) of the tractor are tied to tractor platform.

The platform approach allows for efficient use of design and manufacturing resources. Given the very large investment put into designing and producing each truck model, manufacturers of heavy-duty pickup trucks and vans typically plan on a major redesign for the models every 5 years or more (a key consideration in the choice of the five model year duration during which the vehicle standards are phased in). Recently, EPA's non-GHG heavy-duty engine program provided new emissions standards every three model years. Heavy-duty engine and truck manufacturer product plans typically have fallen into three year cycles to reflect this regime. While the recent non-GHG emissions standards can be handled generally with redesigns of engines and trucks, a complete redesign of a new heavy-duty engine or truck typically occurs on a slower cycle and often does not align in time due to the fact that the manufacturer of engines differs from the truck manufacturer. At the redesign stage, the manufacturer will upgrade or add all of the technology and make most other changes supporting the manufacturer's plans for the next several years, including plans related to emissions, fuel efficiency, and safety regulations.

A redesign of either engine or truck platforms often involves a package of changes designed to work together to meet the various requirements and plans for the model for several model years after the redesign. This often involves significant engineering, development, manufacturing, and marketing resources to create a new product with multiple new features. In order to leverage this significant upfront investment, manufacturers plan vehicle redesigns with several model years of production in mind. Vehicle models are not completely static between redesigns as limited changes are often incorporated for each model year. This interim process is called a refresh of the vehicle and it generally does not allow for major technology changes although more minor ones can be done (e.g., small aerodynamic improvements, etc). More major technology upgrades that affect multiple systems of the vehicle thus occur at the vehicle redesign stage and not in the time period between redesigns.

As discussed below, there are a wide variety of CO 2 and fuel consumption reducing technologies involving several different systems in the engine and vehicle that are available for consideration. Many can involve major changes to the engine or vehicle, such as changes to the engine block and cylinder heads or changes in vehicle shape to improve aerodynamic efficiency. Incorporation of such technologies during the periodic engine, transmission or vehicle redesign process would allow manufacturers to develop appropriate packages of technology upgrades that combine technologies in ways that work together and fit with the overall goals of the redesign. By synchronizing with their multi-year planning process, manufacturers can avoid the large increase in resources and costs that would occur if technology had to be added outside of the redesign process. We considered redesign cycles both in our costing and in assessing needed the lead time required.

As described below, the vast majority of technology on whose performance the final standards are predicated is commercially available and already being utilized to a limited extent across the heavy-duty fleet. Therefore the majority of the emission and fuel consumption reductions which would result from these final rules would result from the increased use of these technologies. EPA and NHTSA also believe that these final rules will encourage the development and limited use of more advanced technologies, such as advanced aerodynamics and hybrid powertrains in some vocational vehicle applications.

In evaluating truck efficiency, NHTSA and EPA have excluded consideration of standards which could result in fundamental changes in the engine or vehicle's performance. Put another way, none of the technology pathways underlying the final standards involve any alteration in vehicle utility. For example, the agencies did not consider approaches that would necessitate reductions in engine power or otherwise limit truck performance. The agencies have thus limited the assessment of technical feasibility and resultant vehicle cost to technologies which maintain freight utility. Similarly, the agencies' choice of attributes on which to base the standards, and the metrics used to measure them, are consciously adopted to preserve the utility of heavy-duty vehicles and engines.

The agencies worked together to determine component costs for each of the technologies and build up the costs accordingly. For costs, the agencies considered both the direct or “piece” costs and indirect costs of individual components of technologies. For the direct costs, the agencies followed a bill of materials approach utilized by the agencies in the light-duty 2012-16 MY vehicle rule. A bill of materials, in a general sense, is a list of components or sub-systems that make up a system—in this case, an item of technology which reduces GHG emissions and fuel consumption. In order to determine what a system costs, one of the first steps is to determine its components and what they cost. NHTSA and EPA estimated these components and their costs based on a number of sources for cost-related information. In general, the direct costs of fuel consumption-improving technologies for heavy-duty pickups and vans are consistent with those used in the light-duty 2012-2016 MY vehicle rule, except that the agencies have scaled up certain costs where appropriate to accommodate the larger size and/or loads placed on parts and systems in the heavy-duty classes relative to the light-duty classes. For loose heavy-duty engines, the agencies have consulted various studies and have exercised engineering judgment when estimating direct costs. For technologies expected to be added to vocational vehicles and combination tractors, the agencies have again consulted various studies and have used engineering judgment to arrive at direct cost estimates. Once costs were determined, they were adjusted to ensure that they were all expressed in 2009 dollars using a ratio of gross domestic product deflators for the associated calendar years.

Indirect costs were accounted for using the ICM approach explained in Chapter 2 of the RIA, rather than using the traditional Retail Price Equivalent (RPE) multiplier approach. For the heavy-duty pickup truck and van cost projections in this final action, the agencies have used ICMs developed for light-duty vehicles (with the exception that here return on capital has been incorporated into the ICMs, where it had not been in the light-duty rule) primarily because the manufacturers involved in this segment of the heavy-duty market are the same manufacturers that build light-duty trucks. For the Class 7 and 8 tractor, vocational vehicle, and heavy-duty engine cost projections in this final rulemaking, EPA contracted with RTI International to update EPA's methodology for accounting for indirect costs associated with changes in direct manufacturing costs for heavy-duty engine and truck manufacturers. [195] In addition to the indirect cost multipliers varying by complexity and time frame, there is no reason to expect that the multipliers would be the same for engine manufacturers as for truck manufacturers. The report from RTI provides a description of the methodology, as well as calculations of new indirect cost multipliers. The multipliers used here include a factor of 5 percent of direct costs representing the return on capital for heavy-duty engines and truck manufacturers. These indirect cost multipliers are intended to be used, along with calculations of direct manufacturing costs, to provide improved estimates of the full additional costs associated with new technologies. The agencies did not receive any adverse comments related to this methodology.

Details of the direct and indirect costs, and all applicable ICMs, are presented in Chapter 2 of the RIA. In addition, for details on the ICMs, please refer to the RTI report (See Docket ID EPA-HQ-OAR-2010-0162-0283). Importantly, the agencies have revised the ICM factors and the way that indirect costs are calculated using the ICMs. As a result, the ICM factors are now higher, the indirect costs are higher and, therefore, technology costs are higher. The changes made to the ICMs and the indirect cost calculations are discussed in Section VIII of this preamble and are detailed in Chapter 2 of the RIA.

EPA and NHTSA believe that the emissions reductions called for by the final standards are technologically feasible at reasonable costs within the lead time provided by the final standards, reflecting our projections of widespread use of commercially available technology. Manufacturers may also find additional means to reduce emissions and lower fuel consumption beyond the technical approaches we describe here. We encourage such innovation through provisions in our flexibility program as discussed in Section IV.

The remainder of this section describes the technical feasibility and cost analysis in greater detail. Further detail on all of these issues can be found in the joint RIA Chapter 2.

A. Class 7-8 Combination Tractor

Class 7 and 8 tractors are used in combination with trailers to transport freight. [196] The variation in the design of these tractors and their typical uses drive different technology solutions for each regulatory subcategory. The agencies are adopting provisions to treat vocational tractors as vocational vehicles instead of as combination tractors, as noted in Section II.B. The focus of this section is on the feasibility of the standards for combination tractors, not the vocational tractors.

EPA and NHTSA collected information on the cost and effectiveness of fuel consumption and CO 2 emission reducing technologies from several sources. The primary sources of information were the 2010 National Academy of Sciences report of Technologies and Approaches to Reducing the Fuel Consumption of Medium- and Heavy-Duty Vehicles, [197] TIAX's assessment of technologies to support the NAS panel report, [198] EPA's Heavy-duty Lumped Parameter Model, [199] the analysis conducted by the Northeast States Center for a Clean Air Future, International Council on Clean Transportation, Southwest Research Institute and TIAX for reducing fuel consumption of heavy-duty long haul combination tractors (the NESCCAF/ICCT study), [200] and the technology cost analysis conducted by ICF for EPA. [201] Following on the EISA of 2007, the National Research Council appointed a NAS committee to assess technologies for improving fuel efficiency of heavy-duty vehicles to support NHTSA's rulemaking. The 2010 NAS report assessed current and future technologies for reducing fuel consumption, how the technologies could be implemented, and identified the potential cost of such technologies. The NAS panel contracted with TIAX to perform an assessment of technologies which provide potential fuel consumption reductions in heavy-duty trucks and engines and the technologies' associated capital costs. Similar to the Lumped Parameter model which EPA developed to assess the impact and interactions of GHG and fuel consumption reducing technologies for light-duty vehicles, EPA developed a new version of that model to specifically address the effectiveness and interactions of the final pickup truck and light heavy-duty engine technologies. The NESCAFF/ICCT study assessed technologies available in 2012 through 2017 to reduce CO 2 emissions and fuel consumption of line haul combination tractors and trailers. Lastly, the ICF report focused on the capital, maintenance, and operating costs of technologies currently available to reduce CO 2 emissions and fuel consumption in heavy-duty engines, combination tractors, and vocational vehicles.

(1) What technologies did the agencies consider to reduce the CO 2 emissions and fuel consumption of combination tractors?

Manufacturers can reduce CO 2 emissions and fuel consumption of combination tractors through use of, among others, engine, aerodynamic, tire, extended idle, and weight reduction technologies. The standards in the final rules are premised on use of these technologies. The agencies note that SmartWay trucks are available today which incorporate the technologies on whose performance the final standards are based. We will also discuss other technologies that could potentially be used, such as vehicle speed limiters, although we are not basing the final standards on their use for the model years covered by this rulemaking, for various reasons discussed below.

In this section we discuss the baseline tractor and engine technologies for the 2010 model year, and then discuss the types of technologies that the agencies considered to improve performance relative to this baseline, while Section III.A.2 discusses the technology packages the agencies used to determine the final standard levels.

(a) Baseline Tractor & Tractor Technologies

Baseline tractor: The agencies developed the baseline tractor to represent the average 2010 model year tractor. Today there is a large spread in aerodynamics in the new tractor fleet. Trucks sold may reflect so-called classic styling (as described in Section II.B.3.c), or may be sold with aerodynamic packages. Based on our review of current truck model configurations and Polk data provided through MJ Bradley, [202] we believe the aerodynamic configuration of the baseline new truck fleet is approximately 25 percent Bin I, 70 percent Bin II, and 5 percent Bin III (as these bin configurations are explained above in Section II.B. (2)(c). The baseline Class 7 and 8 day cab tractor consists of an aerodynamic package which closely resembles the Bin I package described in Section II.B. (2)(c), baseline tire rolling resistance of 7.8 kg/metric ton for the steer tire and 8.2 kg/metric ton, [203] dual tires with steel wheels on the drive axles, and no vehicle speed limiter. The baseline tractor for the Class 8 sleeper cabs contains the same aerodynamic and tire rolling resistance technologies as the baseline day cab, does not include vehicle speed limiters, and does not include an idle reduction technology. The agencies assume the baseline transmission is a 10 speed manual. The agencies received a comment from the ICCT stating that the 0.69 Cd baseline for high roof sleepers published in the NPRM is higher than existing studies show. ICCT cited three studies including a Society of Automotive Engineering paper showing a lower Cd for tractor trailers. The agencies based the average Cd for high roof sleepers on available in use fleet composition data, combined with an assessment of drag coefficient for different truck configurations. The agencies are finalizing the 0.69 baseline Cd for high roof sleeper based on our assessment for the NPRM. However, we will continue to gather information on the composition of the in-use fleet and may alter the baseline in a future action, should more data become available that demonstrates our estimate is incorrect.

Performance from this baseline can be improved by the use of the following technologies:

Aerodynamic technologies: There are opportunities to reduce aerodynamic drag from the tractor, but it is difficult to assess the benefit of individual aerodynamic features. Therefore, reducing aerodynamic drag requires optimizing of the entire system. The potential areas to reduce drag include all sides of the truck—front, sides, top, rear and bottom. The grill, bumper, and hood can be designed to minimize the pressure created by the front of the truck. Technologies such as aerodynamic mirrors and fuel tank fairings can reduce the surface area perpendicular to the wind and provide a smooth surface to minimize disruptions of the air flow. Roof fairings provide a transition to move the air smoothly over the tractor and trailer. Side extenders can minimize the air entrapped in the gap between the tractor and trailer. Lastly, underbelly treatments can manage the flow of air underneath the tractor. As discussed in the TIAX report, the coefficient of drag (Cd) of a SmartWay sleeper cab high roof tractor is approximately 0.60, which is a significant improvement over a truck with no aerodynamic features which has a Cd value of approximately 0.80. [204] The GEM demonstrates that an aerodynamic improvement of a Class 8 high roof sleeper cab with a Cd value of 0.60 (which represents a Bin III tractor) provides a 5 percent reduction in fuel consumption and CO 2 emissions over a truck with a Cd of 0.68.

Lower Rolling Resistance Tires: A tire's rolling resistance results from the tread compound material, the architecture and materials of the casing, tread design, the tire manufacturing process, and its operating conditions (surface, inflation pressure, speed, temperature, etc.). Differences in rolling resistance of up to 50 percent have been identified for tires designed to equip the same vehicle. The baseline rolling resistance coefficient for today's fleet is 7.8 kg/metric ton for the steer tire and 8.2 kg/metric ton for the drive tire, based on sales weighting of the top three manufacturers based on market share. [205] Since 2007, SmartWay trucks have had steer tires with rolling resistance coefficients of less than 6.6 kg/metric ton for the steer tire and less than 7.0 kg/metric ton for the drive tire. [206] Low rolling resistance (LRR) drive tires are currently offered in both dual assembly and single wide-base configurations. Single wide tires can offer rolling resistance reduction along with improved aerodynamics and weight reduction. The GEM demonstrates that replacing baseline tractor tires with tires which meet the Bin I level provides approximately a 4 percent reduction in fuel consumption and CO 2 emissions over the prescribed test cycle, as shown in RIA Chapter 2, Figure 2-2.

Weight Reduction: Reductions in vehicle mass reduce fuel consumption and GHGs by reducing the overall vehicle mass to be accelerated and also through increased vehicle payloads which can allow additional tons to be carried by fewer trucks consuming less fuel and producing lower emissions on a ton-mile basis. Initially for proposal, the agencies considered evaluating vehicle mass reductions on a total vehicle basis for combination tractors. [207] The agencies considered defining a baseline vehicle curb weight and the GEM would have used the vehicle's actual curb weight to calculate the increase or decrease in fuel consumption related to the overall vehicle mass relative to that baseline. After considerable evaluation of this issue, including discussions with the industry, we decided it would not be possible to define a single vehicle baseline mass for the tractors that would be appropriate and representative. Actual vehicle curb weights for these classes of vehicles vary by thousands of pounds dependent on customer features added to vehicles and critical to the function of the vehicle in the particular vocation in which it is used. This is true of vehicles such as Class 8 tractors considered in this section that may appear to be relatively homogenous but which in fact are quite heterogeneous.

This reality led us to the solution we proposed. In the proposal, we reflected mass reductions for specific technology substitutions (e.g., installing aluminum wheels instead of steel wheels) where we could with confidence verify the mass reduction information provided by the manufacturer even though we cannot estimate the actual curb weight of the vehicle. In this way, we accounted for mass reductions where we can accurately account for its benefits.

For the final rules, based on evaluation of the comments, the agencies developed an expanded list of weight reduction opportunities, from which the sum of the weight reduction from the technologies installed on a specific tractor can be input into the GEM as listed in Table II-9 in Section II. The list includes additional components, but not materials, from those proposed in the NPRM. For high strength steel, the weight reduction value is equal to 10 percent of the presumed baseline component weight, as the agencies used a conservative value based on the DOE report. We recognize that there may be additional potential for weight reduction in new high strength steel components which combine the reduction due to the material substitution along with improvements in redesign, as evidenced by the studies done for light-duty vehicles. In the development of the high strength steel component weights, we are only assuming a reduction from material substitution and no weight reduction from redesign, since we do not have any data specific to redesign of heavy-duty components nor do we have a regulatory mechanism to differentiate between material substitution and improved design. We are finalizing for wheels that both aluminum and light weight aluminum are eligible to be used as light-weight materials. Only aluminum and not light weight aluminum can be used as a light-weight material for other components. The reason for this is data was available for light weight aluminum for wheels but was not available for other components.

As explained in Section II.B above, the agencies continue to believe that the 400 pound weight target is appropriate for setting the final combination tractor CO 2 emissions and fuel consumption standards. The agencies agree with the commenter that 400 pounds of weight reduction without the use of single wide tires may not be achievable for all tractor configurations. The agencies have expanded the list of weight reduction components which can be input into the GEM in order to provide the manufacturers with additional means to comply with the combination tractors and to further encourage reductions in vehicle weight. The agencies considered increasing the target value beyond 400 pounds given the additional reduction potential identified in the expanded technology list; however, lacking information on the capacity for the industry to change to these light weight components across the board by the 2014 model year, we have decided to maintain the 400 pound target. The agencies intend to continue to study the potential for additional weight reductions in our future work considering a second phase of truck fuel efficiency and GHG regulations.

A weight reduction of 400 pounds applied to a truck which travels at 70,000 pounds will have a minimal impact on fuel consumption. However, for trucks which operate at the maximum GVWR which occurs approximately in one third of truck miles travelled, a reduced tare weight will allow for additional payload to be carried. The GEM demonstrates that a weight reduction of 400 pounds applied to the payload tons for one third of the trips provides a 0.3 percent reduction in fuel consumption and CO 2 emissions over the prescribed test cycle, as shown in Figure 2-3 of RIA Chapter 2.

Extended Idle Reduction: Auxiliary power units (APU)s, fuel operated heaters, battery supplied air conditioning, and thermal storage systems are among the technologies available today to reduce main engine extended idling from sleeper cabs. Each of these technologies reduces the baseline fuel consumption during idling from a truck without this equipment (the baseline) from approximately 0.8 gallons per hour (main engine idling fuel consumption rate) to approximately 0.2 gallons per hour for an APU. [208] EPA and NHTSA agree with the TIAX assessment of a 6 percent reduction in overall fuel consumption reduction. [209]

Vehicle Speed Limiters: Fuel consumption and GHG emissions increase proportional to the square of vehicle speed. Therefore, lowering vehicle speeds can significantly reduce fuel consumption and GHG emissions. A vehicle speed limiter (VSL), which limits the vehicle's maximum speed, is a simple technology that is utilized today by some fleets (though the typical maximum speed setting is often higher than 65 mph). The GEM shows that using a vehicle speed limiter set at 62 mph on a sleeper cab tractor will provide a 4 percent reduction in fuel consumption and CO 2 emissions over the prescribed test cycles over a baseline vehicle without a VSL or one set above 65 mph. [210]

Transmission: As discussed in the 2010 NAS report, automatic and automated manual transmissions may offer the ability to improve vehicle fuel consumption by optimizing gear selection compared to an average driver. However, as also noted in the report and in the supporting TIAX report, the improvement is very dependent on the driver of the truck, such that reductions ranged from 0 to 8 percent. [211] Well-trained drivers would be expected to perform as well or even better than an automatic transmission since the driver can see the road ahead and anticipate a changing stoplight or other road condition that an automatic transmission can not anticipate. However, poorly-trained drivers that shift too frequently or not frequently enough to maintain optimum engine operating conditions could be expected to realize improved in-use fuel consumption by switching from a manual transmission to an automatic or automated manual transmission. Although we believe there may be real benefits in reduced fuel consumption and GHG emissions through the application of dual clutch, automatic or automated manual transmission technology, we are not reflecting this potential improvement in our standard setting or in our compliance model. We have taken this approach because we cannot say with confidence what level of performance improvement to expect.

Low Friction Transmission, Axle, and Wheel Bearing Lubricants: The 2010 NAS report assessed low friction lubricants for the drivetrain as a 1 percent improvement in fuel consumption based on fleet testing. [212] The light-duty 2012-16 MY vehicle rule and the pickup truck portion of this program estimate that low friction lubricants can have an effectiveness value between 0 and 1 percent compared to traditional lubricants. However, it is not clear if in many heavy-duty applications these low friction lubricants could have competing requirements like component durability issues requiring specific lubricants with different properties than low friction.

Hybrid: Hybrid powertrain development in Class 7 and 8 tractors has been limited to a few manufacturer demonstration vehicles to date. One of the key benefit opportunities for fuel consumption reduction with hybrids is less fuel consumption when a vehicle is idling, but the standard is already premised on use of extended idle reduction so use of hybrid technology would duplicate many of the same emission reductions attributable to extended idle reduction. NAS estimated that hybrid systems would cost approximately $25,000 per tractor in the 2015 through the 2020 time frame and provide a potential fuel consumption reduction of 10 percent, of which 6 percent is idle reduction which can be achieved (less expensively) through the use of other idle reduction technologies. [213] The limited reduction potential outside of idle reduction for Class 8 sleeper cab tractors is due to the mostly highway operation and limited start-stop operation. Due to the high cost and limited benefit during the model years at issue in this action (as well as issues regarding sufficiency of lead time (see Section III.2 (a) below), the agencies are not including hybrids in assessing standard stringency (or as an input to GEM). However as discussed in Section IV, the agencies are providing incentives to encourage the introduction of advanced technologies including hybrid powertrains in appropriate applications.

Management: The 2010 NAS report noted many operational opportunities to reduce fuel consumption, such as driver training and route optimization. The agencies have included discussion of several of these strategies in RIA Chapter 2, but are not using these approaches or technologies in the standard setting process. The agencies are looking to other resources, such as EPA's SmartWay Transport Partnership and regulations that could potentially be promulgated by the Federal Highway Administration and the Federal Motor Carrier Safety Administration, to continue to encourage the development and utilization of these approaches.

(b) Baseline Engine & Engine Technologies

The baseline engine for the Class 8 tractors is a Heavy Heavy-Duty Diesel engine with 15 liters of displacement which produces 455 horsepower. The agencies are using a smaller baseline engine for the Class 7 tractors because of the lower combined weights of this class of vehicles require less power, thus the baseline is an 11L engine with 350 horsepower. The agencies developed the baseline diesel engine as a 2010 model year engine with an aftertreatment system which meets EPA's 0.20 grams of NO X/bhp-hr standard with an SCR system along with EGR and meets the PM emissions standard with a diesel particulate filter with active regeneration. The baseline engine is turbocharged with a variable geometry turbocharger. The following discussion of technologies describes improvements over the 2010 model year baseline engine performance, unless otherwise noted. Further discussion of the baseline engine and its performance can be found in Section III.A.2.6 below.

With respect to stringency level, the agencies received comments from Cummins and Daimler stating that the proposed stringency levels were appropriate for the lead-times. Conversely, the agencies received comments from several environmental groups (UCS, CATF, ACEEE) supporting a greater reduction in engine CO 2 emissions and fuel consumption based on the NAS report. Navistar also stated that the agencies' baseline engine is inappropriate since there is not currently a 0.20 NO X compliant engine in production. A discussion of how the baseline engine configuration can be found below in Section (2)(b)(i).

Navistar also stated that the baseline engines proposed in the NPRM, MY 2010 selective catalytic reduction (SCR)-equipped, could not meet the agencies' statutory obligation to set feasible standards, and requested instead that MY 2010 engines currently in-use be used to meet the feasibility factor. The agencies thus disagree with the statement that SCR is infeasible and therefore, the agencies reaffirm that the engine used as the baseline engine in the agencies' analysis does indeed exist. In fact, several engine families have been certified by EPA using SCR technology over the past two years, all of which have met the 0.20 g/bhp-hr NO X standard. [214] EPA disagrees with Navistar that SCR engines currently certified do not meet this standard. Compliance with the 0.20 g/bhp-hr FTP NO X standard is measured based on an engine's performance when tested over a specific duty cycle (see 40 CFR 86.007-11(a)(2)). This is also true regarding the SET standard (see 40 CFR 86.007-11(a)(3)). Further, the FTP and SET tests are average tests, so emissions could go over 0.20 even for some portion of the test itself. Manufacturers are also required to ensure that their engines meet the NTE standard under all conditions specified in the regulations (see 40 CFR 86.007-11(a)(4)).

Several manufacturers have been able to show compliance with these standards in applications for certification provided to EPA for several engine families. Navistar has provided no information indicating that these tests were false or improper. Indeed, Navistar does not appear to suggest, or provide any evidence, that engines with working SCR systems do not meet the NO X standard. Thus, it is demonstrably false to conclude that the NO X standard cannot be met with SCR-equipped engines.

A more detailed response to these comments appears in Section 6.2 of the Response to Comment document for this rule.

Engine performance for CO 2 emissions and fuel consumption can be improved by use of the following technologies:

Improved Combustion Process: Fuel consumption reductions in the range of 1 to 3 percent over the baseline diesel engine are identified in the 2010 NAS report through improved combustion chamber design, higher fuel injection pressure, improved injection shaping and timing, and higher peak cylinder pressures. [215]

Turbochargers: Improved efficiency of a turbocharger compressor or turbine could reduce fuel consumption by approximately 1 to 2 percent over variable geometry turbochargers in the market today. [216] The 2010 NAS report identified technologies such as higher pressure ratio radial compressors, axial compressors, and dual stage turbochargers as design paths to improve turbocharger efficiency.

Higher efficiency air handling processes: To maximize the efficiency of such processes, induction systems may be improved by manufacturing more efficiently designed flow paths (including those associated with air cleaners, chambers, conduit, mass air flow sensors and intake manifolds) and by designing such systems for improved thermal control. Improved turbocharging and air handling systems must include higher efficiency EGR systems and intercoolers that reduce frictional pressure loss while maximizing the ability to thermally control induction air and EGR. The agencies received comments from Honeywell confirming that turbochargers provide a role in reducing the CO 2 emissions from engines. Other components that offer opportunities for improved flow efficiency include cylinder heads, ports and exhaust manifolds to further reduce pumping losses. Variable air breathing systems such as variable valve actuation may provide additional gains at different loads and speeds. The NESCCAF/ICCT study indicated up to 1.2 percent reduction could be achieved solely through improved EGR systems.

Low Temperature Exhaust Gas Recirculation: Most medium- and heavy-duty vehicle diesel engines sold in the U.S. market today use cooled EGR, in which part of the exhaust gas is routed through a cooler (rejecting energy to the engine coolant) before being returned to the engine intake manifold. EGR is a technology employed to reduce peak combustion temperatures and thus NO X. Low-temperature EGR uses a larger or secondary EGR cooler to achieve lower intake charge temperatures, which tend to further reduce NO X formation. If the NO X requirement is unchanged, low-temperature EGR can allow changes such as more advanced injection timing that will increase engine efficiency slightly more than 1 percent. [217] Because low-temperature EGR reduces the engine's exhaust temperature, it may not be compatible with exhaust energy recovery systems such as turbocompounding or a bottoming cycle.

Engine Friction Reduction: Reduced friction in bearings, valve trains, and the piston-to-liner interface will improve efficiency. Any friction reduction must be carefully developed to avoid issues with durability or performance capability. Estimates of fuel consumption improvements due to reduced friction range from 0 to 2 percent. [218]

Reduced Parasitic Loads: Accessories that are traditionally gear or belt driven by a vehicle's engine can be optimized and/or converted to electric power. Examples include the engine water pump, oil pump, fuel injection pump, air compressor, power-steering pump, cooling fans, and the vehicle's air-conditioning system. Optimization and improved pressure regulation may significantly reduce the parasitic load of the water, air and fuel pumps. Electrification may result in a reduction in power demand, because electrically powered accessories (such as the air compressor or power steering) operate only when needed if they are electrically powered, but they impose a parasitic demand all the time if they are engine driven. In other cases, such as cooling fans or an engine's water pump, electric power allows the accessory to run at speeds independent of engine speed, which can reduce power consumption. The TIAX study used 2 to 4 percent fuel consumption improvement for accessory electrification, with the understanding that electrification of accessories will have more effect in short-haul/urban applications and less benefit in line-haul applications. [219] Bendix, in their comments to the agencies, confirmed that there are engine accessories available that can improve an engine's fuel efficiency.

Selective catalytic reduction: This technology is common on 2010 the medium- and heavy-duty diesel engines used in Class 7 and 8 tractors (and the agencies therefore have included it as part of the baseline engine, as noted above). Because SCR is a highly effective NO X aftertreatment approach, it enables engines to be optimized to maximize fuel efficiency, rather than minimize engine-out NO X. 2010 SCR systems are estimated to result in improved engine efficiency of approximately 3 to 5 percent compared to a 2007 in-cylinder EGR-based emissions system and by an even greater percentage compared to 2010 in-cylinder approaches. [220] As more effective low-temperature catalysts are developed, the NO X conversion efficiency of the SCR system will increase. Next-generation SCR systems could then enable additional efficiency improvements; alternatively, these advances could be used to maintain efficiency while down-sizing the aftertreatment. We estimate that continued optimization of the catalyst could offer 1 to 2 percent reduction in fuel use over 2010 model year systems in the 2014 model year. [221] The agencies estimate an additional 1 to 2 percent reduction may be feasible in the 2017 model year through additional refinement.

Mechanical Turbocompounding: Mechanical turbocompounding adds a low pressure power turbine to the exhaust stream in order to extract additional energy, which is then delivered to the crankshaft. Published information on the fuel consumption reduction from mechanical turbocompounding varies between 2.5 and 5 percent. [222] Some of these differences may depend on the operating condition or duty cycle that was considered by the different researchers. The performance of a turbocompounding system tends to be highest at full load and much less or even zero at light load.

Electric Turbocompounding: This approach is similar in concept to mechanical turbocompounding, except that the power turbine drives an electrical generator. The electricity produced can be used to power an electrical motor supplementing the engine output, to power electrified accessories, or to charge a hybrid system battery. None of these systems have been demonstrated commercially, but modeled results by industry and DOE have shown improvements of 3 to 5 percent. [223]

Bottoming Cycle: An engine with bottoming cycle uses exhaust or other heat energy from the engine to create power without the use of additional fuel. The sources of energy include the exhaust, EGR, charge air, and coolant. The estimates for fuel consumption reduction range up to 10 percent as documented in the 2010 NAS report. [224] However, none of the bottoming cycle or Rankine systems has been demonstrated commercially and are currently in only the research stage. See Section 2.4.2.7 of the RIA and Section II.B above.

(2) Projected Technology Package Effectiveness and Cost

(a) Class 7 and 8 Combination Tractors

EPA and NHTSA project that CO 2 emissions and fuel consumption reductions can be feasibly and cost-effectively achieved in these rules' time frames through the increased application of aerodynamic technologies, LRR tires, weight reduction, extended idle reduction technologies, vehicle speed limiters, and engine improvements. The agencies believe that hybrid powertrains systems for tractors will not be sufficiently developed and the necessary manufacturing capacity put in place to base a standard on any significant volume of hybrid tractors. The agencies are not aware of any full hybrid systems currently developed for long haul tractor applications. To date, hybrid systems for tractors have been primarily focused on idle shutdown technologies and not the broader energy storage and recovery systems necessary to achieve reductions over typical vehicle drive cycles. The final standards reflect the potential for idle shutdown technologies through the GEM model. Further as highlighted by the 2010 NAS report, the agencies do believe that full hybrid powertrains have the potential in the longer term to provide significant improvements in fuel efficiency and to reduce greenhouse gas emissions. However lacking any existing systems or manufacturing base, we cannot conclude such technology will be available in the 2014-2018 timeframe. Developing a full hybrid system itself would be a three to five project followed by several more years to put in place manufacturing capacity. The agencies are including incentives for the use of hybrid technologies to help encourage their development and to reward manufacturers that can produce hybrids through prototype and low volume production methods. The agencies also are not including drivetrain technologies in the standard setting process, as discussed in Section II.B.3.h.iv.

The agencies evaluated each technology and estimated the most appropriate application rate of technology into each tractor subcategory. The next sections describe the effectiveness of the individual technologies, the costs of the technologies, the projected application rates of the technologies into the regulatory subcategories, and finally the derivation of the final standards.

(i) Baseline Tractor Performance

The agencies developed the baseline tractor for each subcategory to represent an average 2010 model year tractor configured as noted earlier. The approach taken by the agencies was to define the individual inputs to the GEM, as shown in Table III-1. For example, the agencies evaluated the industry's tractor offerings and concluded that the average tractor contains a generally aerodynamic shape (such as roof fairings) and avoids classic features such as an exhaust stacks at the B-pillar, which increases drag. As noted earlier, our assessment of the baseline new high roof tractor fleet aerodynamics consists of approximately 25 percent Bin I, 70 percent Bin II, and 5 percent Bin III tractors. The baseline rolling resistance coefficient for today's fleet is 7.8 kg/metric ton for the steer tire and 8.2 kg/metric ton for the drive tire, based on sales weighting of the top three manufacturers based on market share. [225] The agencies assumed no application of vehicle speed limiters, weight reduction technologies, or idle reduction technologies in the baseline tractor. The agencies use the inputs in the GEM to derive the baseline CO 2 emissions and fuel consumption of Class 7 and 8 tractors. The results are included in Table III-1.

Table III-1—Baseline Tractor Definitions Back to Top
Class 7 Class 8
Day cab Day cab Sleeper cab
Low roof Mid roof High roof Low roof Mid roof High roof Low roof Mid roof High roof
Aerodynamics (Cd)                  
Baseline 0.77 0.87 0.73 0.77 0.87 0.73 0.77 0.87 0.70
Steer Tires (CRR kg/metric ton)                  
Baseline 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8
Drive Tires (CRR kg/metric ton)                  
Baseline 8.2 8.2 8.2 8.2 8.2 8.2 8.2 8.2 8.2
Weight Reduction (lb)                  
Baseline 0 0 0 0 0 0 0 0 0
Extended Idle Reduction (gram CO 2 /ton-mile reduction)                  
Baseline N/A N/A N/A N/A N/A N/A 0 0 0
Vehicle Speed Limiter                  
Baseline
Engine                  
Baseline 2010 MY 11L Engine 2010 MY 11L Engine 2010 MY 11L Engine 2010 MY 15L Engine 2010 MY 15L Engine 2010 MY 15L Engine 2010 MY 15L Engine 2010 MY 15L Engine 2010 MY 15L Engine
Table III-2—Class 7 and 8 Tractor Baseline CO 2 Emissions and Fuel Consumption Back to Top
Class 7 Class 8
Day cab Day cab Sleeper cab
Low roof Mid roof High roof Low roof Mid roof High roof Low roof Mid roof High roof
CO 2 (grams CO 2/ton-mile) 116 128 138 88 95 103 80 89 94
Fuel Consumption (gal/1,000 ton-mile) 11.4 12.6 13.6 8.7 9.4 10.1 7.8 8.7 9.3

(ii) Tractor Technology Package Definitions

The agencies' assessment of the final technology effectiveness was developed through the use of the GEM in coordination with chassis testing of three SmartWay certified Class 8 sleeper cabs. The agencies developed the standards through a three-step process. First, the agencies developed technology performance characteristics for each technology, described below. Each technology is associated with an input parameter which is in turn modeled in the GEM. The performance levels for the range of Class 7 and 8 tractor aerodynamic packages and vehicle technologies are described in Table III-3. Second, the agencies combined the technology performance levels with a projected technology application rate to determine the GEM inputs used to set the stringency of the final standards. Third, the agencies input the parameters into GEM and used the output to determine the final CO 2 emissions and fuel consumption levels.

Aerodynamics

The aerodynamic packages are categorized as Bin I, Bin II, Bin III, Bin IV, or Bin V based on the aerodynamic performance determined through testing conducted by the manufacturer. A more complete description of these aerodynamic packages is included in Chapter 2 of the RIA. In general, the CdA values for each package and tractor subcategory were developed through EPA's coastdown testing of tractor-trailer combinations, the 2010 NAS report, and SAE papers.

Tire Rolling Resistance

The rolling resistance coefficient for the tires was developed from SmartWay's tire testing to develop the SmartWay certification, in addition to testing a selection of tractor tires as part of this program. The tire performance was evaluated in three levels—the baseline (average), 15 percent better than the average, and an additional 15 percent improvement. The first 15 percent improvement represents the threshold used to develop SmartWay certified tires for long haul tractors. The second 15 percent threshold represents an incremental step for improvements beyond today's SmartWay level and represents the best in class rolling resistance of the tires we tested.

Weight Reduction

The weight reductions were developed from tire manufacturer information, the Aluminum Association, the Department of Energy, and TIAX, as discussed above in Section II.B.3.e.

Idle Reduction

The benefits for the extended idle reductions were developed from literature, SmartWay work, and the 2010 NAS report. The agencies received comments from multiple stakeholders regarding idle reduction technologies (IRT). Two commenters asked us to revise the default value associated with the IRT technology, and two commenters want to use IRT in GEM even without automatic engine shut down (AES). The agencies proposed AES after 5 minutes with no exceptions to help ensure that the idle reductions are realized in-use. Use of an AES ensures the main engine will be shut down, whereas idle reduction technologies alone do not provide that level of certainty. Without an automatic shutdown of the main engine, actual savings would depend on operator behavior and thus be essentially unverifiable. The agencies are finalizing the calculation as proposed, along with the automotive engine shutdown requirement. Additional details regarding the comments and calculations are included in RIA Section 2.5.4.2.

Several commenters requested that the level of emissions reductions vary in GEM by different idle reduction technologies, and one commenter requested that the application of battery powered APUs be incentivized. The agencies recognize that the level of emission reductions provided by different IRT varies, but are adopting a conservative level to recognize that some vehicles may be sold with only an AES but may then install an IRT in-use. Or some vehicles may be sold with one IRT but then choose to install alternative ones in-use. The agencies cannot verify the savings which depend on operator behavior.

One commenter requested that we provide manufacturers with an option to allow the AES feature to be reprogammable after a specified number of miles or time in service. The agencies recognize that AES may impact the resale value of tractors and, in response to comments, are adopting provisions for the optional expiration of an AES. Thus, the initial buyer could select AES only for the number of miles based on the expected time before resale. Similar to vehicle speed limiters, we would discount the impact based on the full life of the truck (e.g. 1,259,000 miles). Additional detail can be found in RIA Section 2.5.4.2.

Vehicle Speed Limiter

The agencies are not including vehicle speed limiters in the technology package for Class 7 and 8 tractors.

Summary of Technology Performance

Table III-3 describes the performance levels for the range of Class 7 and 8 tractor aerodynamic packages and vehicle technologies.

Table III-3—Class 7 and 8 Tractor Technology Values Back to Top
Class 7 Class 8
Day cab Day cab Sleeper cab
Low/mid roof High roof Low/mid roof High roof Low roof Mid roof High roof
Notes:
aWhile the standards are set based on this value, users would enter another value if AES is not applied or applied for less than the full useful life of the engine.
bVehicle speed limiters are an applicable technology for all Class 7 and 8 tractors, however the standards are not premised on the use of this technology.
Aerodynamics (Cd)              
Bin I 0.77/0.87 0.79 0.77/0.87 0.79 0.77 0.87 0.75
Bin II 0.71/0.82 0.72 0.71/0.82 0.72 0.71 0.82 0.68
Bin III 0.63 0.63 0.60
Bin IV 0.56 0.56 0.52
Bin V 0.51 0.51 0.47
Steer Tires (CRR kg/metric ton)              
Baseline 7.8 7.8 7.8 7.8 7.8 7.8 7.8
Level I 6.6 6.6 6.6 6.6 6.6 6.6 6.6
Level II 5.7 5.7 5.7 5.7 5.7 5.7 5.7
Drive Tires (CRR kg/metric ton)              
Baseline 8.2 8.2 8.2 8.2 8.2 8.2 8.2
Level I 7.0 7.0 7.0 7.0 7.0 7.0 7.0
Level II 6.0 6.0 6.0 6.0 6.0 6.0 6.0
Weight Reduction (lb)              
Control 400 400 400 400 400 400 400
Extended Idle Reduction (gram CO 2 /ton-mile reduction)a              
Control N/A N/A N/A N/A 5 5 5
Vehicle Speed Limiterb              
Control N/A N/A N/A N/A N/A N/A N/A

(iii) Tractor Technology Application Rates

As explained above, vehicle manufacturers often introduce major product changes together, as a package. In this manner the manufacturers can optimize their available resources, including engineering, development, manufacturing and marketing activities to create a product with multiple new features. In addition, manufacturers recognize that a truck design will need to remain competitive over the intended life of the design and meet future regulatory requirements. In some limited cases, manufacturers may implement an individual technology outside of a vehicle's redesign cycle.

With respect to the levels of technology application used to develop the final standards, NHTSA and EPA established technology application constraints. The first type of constraint was established based on the application of fuel consumption and CO 2 emission reduction technologies into the different types of tractors. For example, idle reduction technologies are limited to Class 8 sleeper cabs using the assumption that day cabs are not used for overnight hoteling. A second type of constraint was applied to most other technologies and limited their application based on factors reflecting the real world operating conditions that some combination tractors encounter. This second type of constraint was applied to the aerodynamic, tire, and vehicle speed limiter technologies. Table III-4 specifies the application rates that EPA and NHTSA used to develop the final standards. The agencies received a significant number of comments related to this second basis. In particular, commenters questioned the reasons for not requiring the maximum reduction technology in every case. The agencies have not done so because we have concluded that within each of these individual vehicle categories there are particular applications where the use of the identified technologies would be either ineffective or not technically feasible. The addition of ineffective technologies provides no environmental or fuel efficiency benefit, increases costs and is not a basis upon which to set a maximum feasible improvement. For example, the agencies have not required the use of full aerodynamic vehicle treatments on 100 percent of tractors because we know that in many applications (for example gravel truck engaged in local aggregate delivery) the added weight of the aerodynamic technologies will increase fuel consumption and hence CO 2 emissions to a greater degree than the reduction that would be accomplished from the more aerodynamic nature of the tractor. To simply set the standard based on the largest reduction possible estimated narrowly over a single test procedure while ignoring the in-use effects of the technology would in this case result in a perverse outcome that is not in keeping with the agencies' goals or the requirements of the CAA and EISA.

Aerodynamics Application Rate

The impact of aerodynamics on a truck's efficiency increases with vehicle speed. Therefore, the usage pattern of the truck will determine the benefit of various aerodynamic technologies. Sleeper cabs are often used in line haul applications and drive the majority of their miles on the highway travelling at speeds greater than 55 mph. The industry has focused aerodynamic technology development, including SmartWay tractors, on these types of trucks. Therefore the agencies are adopting the most aggressive aerodynamic technology application to this regulatory subcategory. All of the major manufacturers today offer at least one SmartWay truck model. The 2010 NAS Report on heavy-duty trucks found that manufacturers indicated that aerodynamic improvements which yield 3 to 4 percent fuel consumption reduction or 6 to 8 percent reduction in Cd values, beyond technologies used in today's SmartWay trucks are achievable. [226] The aerodynamic application rate for Class 8 sleeper cab high roof cabs (i.e., the degree of technology application on which the stringency of the final standard is premised) consists of 20 percent of Bin IV, 70 percent Bin III, and 10 percent Bin II reflecting our assessment of the fraction of tractors in this segment that can successfully apply these aerodynamic packages.

The 90 percent of tractors that we project can either be Bin II or Bin III equipped reflects the bulk of Class 8 high roof sleeper cab applications. We are not projecting a higher fraction of Bin III aerodynamic systems because of the limited lead time for the program and the need for these more advanced technologies to be developed and demonstrated before being applied across a wider fraction of the fleet. Aerodynamic improvements through new tractor designs and the development of new aerodynamic components is an inherently slow and iterative process. Aerodynamic impacts are highly nonlinear and often reflect unexpected interactions between multiple components. Given the nature of aerodynamic improvements it is inherently difficult to estimate the degree to which improvements can be made beyond previously demonstrated levels. The changes required for Bins III and IV reflect the kinds of improvements projected in the Department of Energy's Supertruck program. That program assumes that such systems can be demonstrated on vehicles by 2017. In this case, the agencies are projecting that truck OEMs will be able to begin implementing these aerodynamic technologies prior to 2017 on a limited scale. Importantly, our averaging, banking and trading provisions provide manufacturers with the flexibility to implement these technologies over time even though the standard changes in a single step.

The final aerodynamic application for the other tractor regulatory categories is less aggressive than for the Class 8 sleeper cab high roof. The agencies recognize that there are truck applications which require on/off-road capability and other truck functions which restrict the type of aerodynamic equipment applicable. We also recognize that these types of trucks spend less time at highway speeds where aerodynamic technologies have the greatest benefit. The 2002 VIUS data ranks trucks by major use. [227] The heavy trucks usage indicates that up to 35 percent of the trucks may be used in on/off-road applications or heavier applications. The uses include construction (16 percent), agriculture (12 percent), waste management (5 percent), and mining (2 percent). Therefore, the agencies analyzed the technologies to evaluate the potential restrictions that would prevent 100 percent application of SmartWay technologies for all of the tractor regulatory subcategories.

As discussed in Section II.B.2.c, in response to comments received from manufacturers making some of these same points, the agencies are finalizing only two aerodynamic bins for low and mid roof tractors. The agencies are reducing the number of bins for these tractors from the proposal to reflect the actual range of aerodynamic technologies effective in low and mid roof tractor applications. The aerodynamic improvements to the bumper, hood, windshield, mirrors, and doors are developed for the high roof tractor application and then carried over into the low and mid roof applications. As mentioned in Section II.B.2.c, the types of designs that would move high roof tractors from a Bin III to Bins IV and V include features such as gap reducers and integral roof fairings which would not be appropriate on low and mid roof tractors. Thus, the agencies are differentiating the aerodynamic performance for low- and mid-roof tractors into two bins—Bin I and Bin II. The application rates in the low and mid roof categories are the same as proposed, but aggregated into just two bins. Bin I for these tractors corresponds to the proposed “Classic” and “Conventional” bins and Bin II corresponds to the proposed “SmartWay,” “Advanced SmartWay,” and “Advanced SmartWay II” bins.

Low Rolling Resistance Tire Application Rate

At proposal, the agencies stated that at least one LRR tire model is available today that meets the rolling resistance requirements of the Level I and Level II tire packages so the 2014 MY should afford manufacturers sufficient lead time to install these packages. EPA and NHTSA conducted additional evaluation testing on HD tires used for tractors. The agencies also received several comments on the suitability of low rolling resistance tires for various HD truck applications. The summary of the agencies findings and a response to issues raised by commenters is presented in Section II.D(1)(a).

The agencies note that baseline rolling resistance level for tires installed on tractors is approximately equivalent to what the agencies consider to be low rolling resistance tires for vocational vehicles because of the tire manufacturer's focus on improving the rolling resistance of tractor tires. For the tire manufacturers to further reduce tire rolling resistance, the manufacturers must consider several performance criteria that affect tire selection. The characteristics of a tire also influence durability, traction control, vehicle handling, comfort, and retreadability. A single performance parameter can easily be enhanced, but an optimal balance of all the criteria will require improvements in materials and tread design at a higher cost, as estimated by the agencies. Tire design requires balancing performance, since changes in design may change different performance characteristics in opposing directions. Similar to the discussion regarding lesser aerodynamic technology application in tractor segments other than sleeper cab high roof, the agencies believe that the final standards should not be premised on 100 percent application of Level II tires in all tractor segments given the interference with vehicle utility that would result. The agencies are basing their analyses on application rates that vary by subcategory recognizing that some subcategories require a different balancing of performance versus rolling resistance.

Weight Reduction Technology Application Rate

The agencies proposed setting the 2014 model year tractor standards using 100 percent application of a 400 pound weight reduction package. Volvo and ATA stated in their comments that not all fleets can use single wide tires and if this is the case the 400 pound weight reduction cannot be met. The agencies also received comments from MEMA, Navistar, American Chemistry Council, the Auto Policy Center, Iron and Steel Institute, Arvin Meritor, Aluminum Association, and environmental groups and NGOs identifying other potential weight reduction opportunities for tractors. As described in Section II.B.3.e above, the agencies are adopting an expanded list of weight reduction options which can be input into the GEM for the final rulemaking.

As also explained in that earlier discussion, the agencies, upon further analysis, continue to believe that a 400 pound weight reduction package is appropriate for tractors in the time frame. As stated in Section II.B.2.e above, for tractors where single wide tires are not appropriate, the manufacturers have additional options available to achieve weight reduction, such as body panels and chassis components as documented in the earlier discussion. The agencies have extended the list of weight reduction components in order to provide the manufacturers with additional means to comply with the combination tractors and to further encourage reductions in vehicle weight. The agencies considered increasing the target value beyond 400 pounds given the additional reduction potential components identified in the expanded list; however, lacking information on the capacity for the industry to change to these light weight components across the board by the 2014 model year, we have decided to maintain the 400 pound target. The agencies intend to continue to study the potential for additional weight reductions in our future work considering a second phase of truck fuel efficiency and GHG regulations.

Idle Reduction Technology Application Rate

Idle reduction technologies provide significant reductions in fuel consumption and CO 2 emissions for Class 8 sleeper cabs and are available on the market today, and therefore will be available in the 2014 model year. There are several different technologies available to reduce idling. These include APUs, diesel fired heaters, and battery powered units. Our discussions with manufacturers indicate that idle technologies are sometimes installed in the factory, but it is also a common practice to have the units installed after the sale of the truck. We would like to continue to incentivize this practice and to do so in a manner that the emission reductions associated with idle reduction technology occur in use. Therefore, as proposed, we are allowing only idle emission reduction technologies with include an automatic engine shutoff (AES). We are also adopting some override provisions in response to comments we received (as explained below). As proposed, we are adopting a 100 percent application rate for this technology for Class 8 sleeper cabs, even though the current fleet is estimated to have a 30 percent application rate. The agencies are unaware of reasons why AES with extended idle reduction technologies could not be applied to all tractors with a sleeper cab, except those deemed a vocational tractor, in the available lead time.

One commenter stated the application rate of AES should be less than 100 percent, but did not recommend an alternative application rate or provide justification for a change. The agencies re-evaluated the proposed 100 percent application rate and determined that a 100 percent application rate for this technology for Class 8 sleeper cabs remains appropriate. The agencies have also considered the many comments which raised concerns about the proposed mandatory 5 minute automatic engine shut down without override capability (in terms of safety, extreme temperatures and low battery conditions). To avoid unintended adverse impacts, we are adopting limited override provisions. Three of the five exceptions are similar to those currently in effect under a California Air Resources Board (CARB) regulation. CARB provides AES exceptions (or overrides) within its existing heavy-duty vehicle anti-idling laws, which were developed to address these same types of concerns. The exceptions we are adopting include override capability during exhaust emissions control device regeneration, during engine servicing and maintenance, when battery state of charge is too low, in extreme ambient temperatures, when engine coolant temperature is too low, and during PTO operation. The RIA provides more detail about these final override provisions in Section 2.5.4.3.

The agencies received comment that we should extend the idle reduction benefits beyond Class 8 sleepers, including Class 7 tractors and vocational vehicles. The agencies reviewed literature to quantify the amount of idling which is conducted outside of hoteling operations. One study, conducted by Argonne National Laboratory, identified several different types of trucks which might idle for extended amounts of time during the work day. [228] Idling may occur during the delivery process, queuing at loading docks or border crossings, during power take off operations, or to provide comfort during the work day. However, the study provided only “rough estimates” of the idle time and energy use for these vehicles. The agencies are not able to appropriately develop a baseline of workday idling for the other types of vehicles and identify the percent of this idling which could be reduced through the use of AES. Absent such information, the agencies cannot justify adding substantial cost for AES systems with such uncertain benefits.

Vehicle Speed Limiter Application Rate

Vehicle speed limiters may be used as a technology to meet the standard, but in setting the standard we assumed a zero percent application rate of vehicle speed limiters. Although we believe vehicle speed limiters are a simple, easy to implement, and inexpensive technology, we want to leave the use of vehicles speed limiters to the truck purchaser. Since truck fleets purchase trucks today with owner set vehicle speed limiters, we considered not including VSLs in our compliance model. However, we have concluded that we should allow the use of VSLs that cannot be overridden by the operator as a means of compliance for vehicle manufacturers that wish to offer it and truck purchasers that wish to purchase the technology. In doing so, we are providing another means of meeting that standard that can lower compliance cost and provide a more optimal vehicle solution for some truck fleets. For example, a local beverage distributor may operate trucks in a distribution network of primarily local roads. Under those conditions, aerodynamic fairings used to reduce aerodynamic drag provide little benefit due to the low vehicle speed while adding additional mass to the vehicle. A vehicle manufacturer could choose to install a VSL set a 55 mph for this customer. The resulting truck modeled in GEM could meet our final emission standard without the use of any specialized aerodynamic fairings. The resulting truck would be optimized for its intended application and would be fully compliant with our program all at a lower cost to the ultimate truck purchaser. [229]

As discussed in Section II.B.2.g above, we have chosen not to base the standards on performance of VSLs because of concerns about how to set a realistic application rate that avoids unintended adverse impacts. Although we expect there will be some use of VSL, currently it is used when the fleet involved decides it is feasible and practicable and increases the overall efficiency of the freight system for that fleet operator. However, at this point the agencies are not in a position to determine in how many additional situations use of a VSL would result in similar benefits to overall efficiency. Therefore, the agencies are not premising the final standards on use of VSL, and instead will rely on the industry to select VSL when circumstances are appropriate for its use. The agencies have not included either the cost or benefit due to VSLs in analysis of the program's costs and benefits. Implementation of this program may provide greater information for using this technology in standard setting in the future. Many stakeholders including the American Trucking Association have advocated for more widespread use of vehicle speed limits to address fuel efficiency and greenhouse gas emissions. The Center for Biological Diversity (CBD) argued the agencies should reflect the use of VSLs in setting the standard for tractors rather than assuming no VSL use in determining the appropriate standard. The agencies have chosen not to do so because, as explained, we are not able at this time to quantify to potential loss in utility due to the use of VSLs. Absent this information, we cannot make a determination regarding the reasonableness of setting a standard based on a particular VSL level. In confirmation, a number of commenters most notably the Owner Operator Independent Drivers Association (OOIDA) suggest that VSLs could significantly impact the ability of a vehicle to deliver goods against a fixed schedule and hence would significantly impact its utility. ATA commented that limited flexibility must be built into speed limiters as not to interfere with NHTSA planned rulemaking in response to 2006 ATA petition and its 2008 Sustainability Plan. Similar comments were received from DTNA requesting that the agencies consider any NHTSA safety regulations that may also be regulating VSLs. NHTSA plans to issue a rule in 2012 addressing the safety performance features of VSLs.

Table III-4 provides the final application rates of each technology broken down by weight class, cab configuration, and roof height.

Table III-4—Final Technology Application Rates for Class 7 and 8 Tractors Back to Top
Class 7 Class 8
Day cab Day cab Sleeper cab
Low/mid roof High roof Low/mid roof High roof Low roof Mid roof High roof
[In percent]
Aerodynamics (Cd)              
Bin I 40 0 40 0 30 30 0
Bin II 60 30 60 30 70 70 10
Bin III 60 60 70
Bin IV 10 10 20
Bin V 0 0 0
Steer Tires (CRR kg/metric ton)              
Baseline 40 30 40 30 30 30 10
Bin I 50 60 50 60 60 60 70
Bin II 10 10 10 10 10 10 20
Drive Tires (CRR kg/metric ton)              
Baseline 40 30 40 30 30 30 10
Bin I 50 60 50 60 60 60 70
Bin II 10 10 10 10 10 10 20
Weight Reduction (lb)              
400 lb. Weight Reduction 100 100 100 100 100 100 100
Extended Idle Reduction (gram CO 2 /ton-mile reduction)              
AES N/A N/A N/A N/A 100 100 100
Vehicle Speed Limiter              
VSL 0 0 0 0 0 0 0

(iv) Derivation of the Final Tractor Standards

The agencies used the technology inputs and final technology application rates in GEM to develop the final fuel consumption and CO 2 emissions standards for each subcategory of Class 7 and 8 combination tractors. The agencies derived a scenario tractor for each subcategory by weighting the individual GEM input parameters included in Table III-3 with the application rates in Table III-4. For example, the Cd value for a Class 8 Sleeper Cab High Roof scenario case was derived as 10 percent times 0.68 plus 70 percent times 0.60 plus 20 percent times 0.55, which is equal to a Cd of 0.60. Similar calculations were done for tire rolling resistance, weight reduction, idle reduction, and vehicle speed limiters. To account for the two final engine standards, the agencies assumed a compliant engine in GEM. [230] In other words, EPA is finalizing the use of a 2014 model year fuel consumption map in GEM to derive the 2014 model year tractor standard and a 2017 model year fuel consumption map to derive the 2017 model year tractor standard. [231] The agencies then ran GEM with a single set of vehicle inputs, as shown in Table III-5, to derive the final standards for each subcategory. Additional detail is provided in the RIA Chapter 2.

Table III-5—GEM Inputs for the Class 7 and 8 Tractor Standard Setting Back to Top
Class 7 Class 8
Day cab Day cab Sleeper cab
Low roof Mid roof High roof Low roof Mid roof High roof Low roof Mid roof High roof
Aerodynamics (Cd)                
0.73 0.84 0.65 0.73 0.84 0.65 0.73 0.84 0.59
Steer Tires (CRR kg/metric ton)                
6.99 6.99 6.87 6.99 6.99 6.87 6.87 6.87 6.54
Drive Tires (CRR kg/metric ton)                
7.38 7.38 7.26 7.38 7.38 7.26 7.26 7.26 6.92
Weight Reduction (lb)                
400 400 400 400 400 400 400 400 400
Extended Idle Reduction (gram CO 2 /ton-mile reduction)                
N/A N/A N/A N/A N/A N/A 5 5 5
Vehicle Speed Limiter                
Engine                
2014/17 MY 11L Engine 2014/17 MY 11L Engine 2014/17 MY 11L Engine 2014/17 MY 15L Engine 2014/17 MY 15L Engine 2014/17 MY 15L Engine 2014/17 MY 15L Engine 2014/17 MY 15L Engine 2014/17 MY 15L Engine

The level of the 2014 and 2017 model year final standards and percent reduction from the baseline for each subcategory are included in Table III-6.

Table III-6—Final 2014 and 2017 Model Year Tractor Reductions Back to Top
2014 Model Year CO 2 Grams per Ton-Mile      
Day cab Sleeper cab
Class 7 Class 8 Class 8
Low Roof 107 81 68
Mid Roof 119 88 76
High Roof 124 92 75
2014-2016 Model Year Gallons of Fuel per 1,000 Ton-Mile232      
Day cab Sleeper cab
Class 7 Class 8 Class 8
Low Roof 10.5 8.0 6.7
Mid Roof 11.7 8.7 7.4
High Roof 12.2 9.0 7.3
2017 Model Year CO 2 Grams per Ton-Mile      
Day cab Sleeper cab
Class 7 Class 8 Class 8
Low Roof 104 80 66
Mid Roof 115 86 73
High Roof 120 89 72
2017 Model Year and Later Gallons of Fuel per 1,000 Ton-Mile      
Day cab Sleeper cab
Class 7 Class 8 Class 8
Low Roof 10.2 7.8 6.5
Mid Roof 11.3 8.4 7.2
High Roof 11.8 8.7 7.1

Asummary of the final technology package costs is included in Table III-7 with additional details available in the RIA Chapter 2.

Table III-7—Class 7 and 8 Tractor Technology Costs Inclusive of Indirect Cost Markups in the 2014 Model Year a (2009$) Back to Top
Class 7 Class 8
Day cab Day cab Sleeper cab
Low/mid roof High roof Low/mid roof High roof Low roof Mid roof High roof
Notes:
aCosts shown are for the 2014 model year so do not reflect learning impacts which would result in lower costs for later model years. For a description of the learning impacts considered in this analysis and how it impacts technology costs for other years, refer to Chapter 2 of the RIA (see RIA 2.2.2).
bNote that values in this table include penetration rates. Therefore, the technology costs shown reflect the average cost expected for each of the indicated classes. To see the actual estimated technology costs exclusive of penetration rates, refer to Chapter 2 of the RIA (see RIA 2.9 in particular).
cEPA's air conditioning standards are presented in Section II.E.5 above.
Aerodynamics $675 $924 $675 $924 $962 $983 $1,627
Steer Tires 68 68 68 68 68 68 68
Drive Tires 63 63 126 126 126 126