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Proposed Rule

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

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AGENCIES:

Environmental Protection Agency (EPA) and National Highway Traffic Safety Administration (NHTSA), Department of Transportation (DOT).

ACTION:

Proposed rules.

SUMMARY:

EPA and NHTSA, on behalf of the Department of Transportation, are each proposing rules to establish a comprehensive Heavy-Duty National Program that will reduce greenhouse gas emissions and increase fuel efficiency 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 proposed fuel consumption standards and EPA's proposed carbon dioxide (CO2) emissions standards would be tailored to each of three regulatory categories of heavy-duty vehicles: Combination Tractors; Heavy-Duty Pickup Trucks and Vans; and Vocational Vehicles, as well as gasoline and diesel heavy-duty engines. EPA's proposed hydrofluorocarbon emissions standards would apply to air conditioning systems in tractors, pickup trucks, and vans, and EPA's proposed nitrous oxide (N2 O) and methane (CH4) emissions standards would apply to all heavy-duty engines, pickup trucks, and vans. EPA is also requesting comment on possible alternative CO2-equivalent approaches for model year 2012-14 light-duty vehicles.

EPA's proposed greenhouse gas emission standards under the Clean Air Act would begin with model year 2014. NHTSA's proposed fuel consumption standards under the Energy Independence and Security Act of 2007 would be voluntary in model years 2014 and 2015, becoming mandatory with model year 2016 for most regulatory categories. Commercial trailers would not be regulated in this phase of the Heavy-Duty National Program, although there is a discussion of the possibility of future action for trailers.

DATES:

Comments: Comments on all aspects of this proposal must be received on or before January 31, 2011. Under the Paperwork Reduction Act, comments on the information collection provisions must be received by the Office of Management and Budget on or before December 30, 2010. See the SUPPLEMENTARY INFORMATION section on “Public Participation” for more information about written comments.

Public Hearings: NHTSA and EPA will jointly hold two public hearings on the following dates: November 15, 2010 in Chicago, IL; and November 18, 2010 in Cambridge, MA, as announced at 75 FR 67059, November 1, 2010. The hearing in Chicago will start at 11 a.m. local time and continue until 5 p.m. or until everyone has had a chance to speak. The hearing in Cambridge will begin at 10 a.m. and continue until 5 p.m. or until everyone has had a chance to speak. See “How Do I Participate in the Public Hearings?” below at B. (7) under the SUPPLEMENTARY INFORMATION section on “Public Participation” for more information about the public hearings.

ADDRESSES:

Submit your comments, identified by Docket ID No. NHTSA-2010-0079 and/or EPA-HQ-OAR-2010-0162, by one of the following methods:

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.

EPA: Air Docket, Environmental Protection Agency, EPA Docket Center, Mailcode: 6102T, 1200 Pennsylvania Ave., NW., Washington, DC 20460. In addition, please mail a copy of your comments on the information collection provisions to the Office of Information and Regulatory Affairs, Office of Management and Budget (OMB), Attn: Desk Officer for EPA, 725 17th St., NW., Washington, DC 20503.

  • Hand Delivery:

NHTSA: West Building, Ground Floor, Rm. W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m. Eastern Time, Monday through Friday, except Federal Holidays.

EPA: EPA Docket Center, (Air Docket), U.S. Environmental Protection Agency, EPA West Building, 1301 Constitution Ave., NW., Room: 3334, Mail Code 2822T, Washington, DC. Such deliveries are only accepted during the Docket's normal hours of operation, and special arrangements should be made for deliveries of boxed information.

Instructions: Direct your comments to Docket ID No. NHTSA-2010-0079 and/or EPA-HQ-OAR-2010-0162. See the SUPPLEMENTARY INFORMATION section on “Public Participation” for additional instructions on submitting written comments.

Docket: All documents in the docket are listed in the http://www.regulations.gov index. 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, will be publicly available only in hard copy in EPA's docket, but may be available electronically in NHTSA's docket at regulations.gov. Publicly available docket materials are available either electronically in http://www.regulations.gov or in hard copy at the following locations:

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.

EPA: EPA Docket Center, EPA/DC, EPA West, Room 3334, 1301 Constitution Ave., NW., 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 Air Docket is (202) 566-1742.

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FOR FURTHER INFORMATION CONTACT:

NHTSA: Rebecca Yoon, 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 Assessment and Standards Division Hotline; telephone number; (734) 214-4636; e-mail asdinfo@epa.gov.

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SUPPLEMENTARY INFORMATION:

Does this action apply to me?

This action would affect 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 as 3/4-ton and 1-ton pickup trucks and vans.[1] 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 standards and corporate average fuel economy standards issued for light-duty model year 2012-2016 vehicles. This action also includes a discussion of the possible future regulation of commercial trailers and is requesting comment on possible alternative CO2-equivalent approaches for model year 2012-14 light-duty vehicles. Potentially affected categories and entities include the following:

This table is not intended to be exhaustive, but rather provides a guide for readers regarding entities likely to be regulated by this proposal. This table lists the types of entities that the agencies are now aware could potentially be regulated by this action. Other types of entities not listed in the table could also be regulated. To determine whether your activities may be regulated by this action, you should carefully examine the applicability criteria in 40 CFR parts 1036 and 1037, 49 CFR parts 523, 534, and 535, and 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.

B. Public Participation

NHTSA and EPA request comment on all aspects of these joint proposed rules. This section describes how you can participate in this process.

(1) How do I prepare and submit comments?

In this joint proposal, there are many aspects of the program common to both EPA and NHTSA. For the convenience of all parties, comments submitted to the EPA docket (whether hard copy or electronic) will be considered comments submitted to the NHTSA docket, and vice versa. An exception is that comments submitted to the NHTSA docket on the Draft Environmental Impact Statement will not be considered submitted to the EPA docket. Therefore, the public only needs to submit comments to either one of the two agency dockets. Comments that are submitted for consideration by one agency should be identified as such, and comments that are submitted for consideration by both agencies should be identified as such. Absent such identification, each agency will exercise its best judgment to determine whether a comment is submitted on its proposal.

Further instructions for submitting comments to either the EPA or NHTSA docket are described below.

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NHTSA: Your comments must be written and in English. To ensure that your comments are correctly filed in the Docket, please include the Docket I.D No. NHTSA-2010-0079 in your comments. By regulation, your comments must not be more than 15 pages long (49 CFR 553.21). NHTSA established this limit to encourage you to write your primary comments in a concise fashion. However, you may attach necessary additional documents to your comments. There is no limit on the lenght of the attachments. If you are submitting comments electronically as a PDF (Adobe) file, we ask that the documents submitted be scanned using the Optical Character Recognition (OCR) process, thus allowing the agencies to search and copy certain portions of your submissions.[2] Please note that pursuant to the Data Quality Act, in order for the substantive data to be relied upon and used by the agencies, it must meet the information quality standards set forth in the OMB and Department of Transportation (DOT) Data Quality Act quidelines. Accordingly, we encourage you to consult the guidelines in preparing your comments. OMB's guidelines may be accessed at http://www.whitehouse.gov/​omb/​fedreg/​reproducible.html. DOT's guidelines may be access at http://regs.dot.gov.

EPA: Direct your comments to Docket ID No EPA-HQ-OAR-2010-0162. EPA's policy is that all comments received will be included in the public docket without change and may be made available online at http://www.regulations.gov, including any personal information provided, unless the comment includes information claimed to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Do not submit information that you consider to be CBI or otherwise protected through http://www.regulations.gov or e-mail. The http://www.regulations.gov Web site is an “anonymous access” system, which means EPA will not know your identity or contact information unless you provide it in the body of your comment. If you send an e-mail comment directly to EPA without going through http://www.regulations.gov your e-mail address will be automatically captured and included as part of the comment that is placed in the public docket and made available on the Internet. If you submit an electronic comment, EPA recommends that you include your name and other contact information in the body of your comment and with any disk or CD-ROM you submit. If EPA cannot read your comment due to technical difficulties and cannot contact you for clarification, EPA may not be able to consider your comment. Electronic files should avoid the use of special characters, any form of encryption, and be free of any defects or viruses. For additional information about EPA's public docket visit the EPA Docket Center homepage at http://www.epa.gov/​epahome/​dockets.htm.

(2) Tips for Preparing Your Comments

When submitting comments, remember to:

  • Identify the rulemaking by docket number and other identifying information (subject heading, Federal Register date and page number).
  • Follow directions—The agencies may ask you to respond to specific questions or organize comments by referencing a part or section number from the Code of Federal Regulations.
  • Explain why you agree or disagree, suggest alternatives, and substitute language for your requested changes.
  • Describe any assumptions and provide any technical information and/or data that you used.
  • If you estimate potential costs or burdens, explain how you arrived at your estimate in sufficient detail to allow for it to be reproduced.
  • Provide specific examples to illustrate your concerns, and suggest alternatives.
  • Explain your views as clearly as possible, avoiding the use of profanity or personal threats.
  • Make sure to submit your comments by the comment period deadline identified in the DATES section above.

(3) How can I be sure that my comments were received?

NHTSA: If you submit your comments by mail and wish Docket Management to notify you upon its receipt of your comments, enclose a self-addressed, stamped postcard in the envelope containing your comments. Upon receiving your comments, Docket Management will return the postcard by mail.

(4) How do I submit confidential business information?

Any CBI submitted to one of the agencies will also be available to the other agency.[3] However, as with all public comments, any CBI information only needs to be submitted to either one of the agencies' dockets and it will be available to the other. Following are specific instructions for submitting CBI to either agency.

NHTSA: If you wish to submit any information under a claim of confidentiality, you should submit three copies of your complete submission, including the information you claim to be CBI, to the Chief Counsel, NHTSA, at the address given above under FOR FURTHER INFORMATION CONTACT. When you send a comment containing CBI, you should include a cover letter setting forth the information specified in our CBI regulation. In addition, you should submit a copy from which you have deleted the claimed CBI to the Docket by one of the methods set forth above.

EPA: Do not submit CBI to EPA through http://www.regulations.gov or e-mail. Clearly mark the part or all of the information that you claim to be CBI. For CBI in a disk or CD-ROM that you mail to EPA, mark the outside of the disk or CD-ROM as CBI and then identify electronically within the disk or CD-ROM the specific information that is claimed as CBI. In addition to one complete version of the comment that includes information claimed as CBI, a copy of the comment that does not contain the information claimed as CBI must be submitted for inclusion in the public docket. Information so marked will not be disclosed except in accordance with procedures set forth in 40 CFR part 2.

(5) Will the agencies consider late comments?

NHTSA and EPA will consider all comments received before the close of business on the comment closing date indicated above under DATES. To the extent practicable, we will also consider comments received after that date. If interested persons believe that any new information the agency places in the docket affects their comments, they may submit comments after the closing date concerning how the agency should consider that information for the final rules. However, the agencies' ability to consider any such late comments in this rulemaking will be limited due to the time frame for issuing the final rules.

If a comment is received too late for us to practicably consider in developing the final rules, we will consider that comment as an informal suggestion for future rulemaking action.Start Printed Page 74155

How can I read the comments submitted by other people?

You may read the materials placed in the dockets for this document (e.g., the comments submitted in response to this document by other interested persons) at any time by going to http://www.regulations.gov. Follow the online instructions for accessing the dockets. You may also read the materials at the NHTSA Docket Management Facility or the EPA Docket Center by going to the street addresses given above under ADDRESSES.

How do I participate in the public hearings?

EPA and NHTSA will jointly host two public hearings. The November 15 hearing will be held at the Millennium Knickerbocker Hotel Chicago, 163 East Walton Place (at N. Michigan Ave.), Chicago, Illinois 60611. The November 18, 2010 hearing will be held at the Hyatt Regency Cambridge, 575 Memorial Drive, Cambridge, Massachusetts 02139-4896. If you would like to present oral testimony at a public hearing, we ask that you notify both the NHTSA and EPA contact persons listed under FOR FURTHER INFORMATION CONTACT at least ten days before the hearing. Once the agencies learn how many people have registered to speak at the public hearings, we will allocate an appropriate amount of time to each participant, allowing time for necessary breaks. For planning purposes, each speaker should anticipate speaking for approximately ten minutes, although we may need to shorten that time if there is a large turnout. We request that you bring three copies of your statement or other material for the agencies' panels. To accommodate as many speakers as possible, we prefer that speakers not use technological aids (e.g., audio-visuals, computer slideshows). In addition, we will reserve a block of time for anyone else in the audience who wants to give testimony.

Each hearing will be held at a site accessible to individuals with disabilities. Individuals who require accommodations such as sign language interpreters should contact the persons listed under FOR FURTHER INFORMATION CONTACT section above no later than ten days before the date of the hearing.

EPA and NHTSA will conduct the hearings informally, and technical rules of evidence will not apply. We will arrange for a written transcript of each hearing and keep the official records of the hearings open for 30 days to allow you to submit supplementary information. You may make arrangements for copies of a transcript directly with the court reporter.

C. Additional Information About This Rulemaking

EPA's Advance Notice of Proposed Rulemaking for regulating greenhouse gases under the CAA (see 73 FR 44353, July 30, 2008) included a discussion of possible rulemaking paths for the heavy-duty transportation sector. This notice of proposed rulemaking relies in part on information that was obtained from that notice, which can be found in Public Docket EPA-HQ-OAR-2008-0318. That docket is incorporated into the docket for this action, EPA-HQ-OAR-2010-0162.

Table of Contents

A. Does this action apply to me?

B. Public Participation

C. Additional Information About This Rulemaking

I. Overview

A. Introduction

B. Building Blocks of the Heavy-Duty National Program

C. Summary of the Proposed 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. Proposed GHG and Fuel Consumption Standards for Heavy-Duty Engines and Vehicles

A. What vehicles would 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 Provisions

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. Proposed Regulatory Flexibility Provisions

A. Averaging, Banking, and Trading Program

B. Additional Proposed Flexibility Provisions

V. NHTSA and EPA Proposed 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 would this proposed 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 CO2 Concentrations, Global Mean Temperature, Sea Level Rise, and Ocean pH Associated With the Proposal's GHG Emissions Reductions

VII. How would this proposal 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 proposed program?

A. Conceptual Framework for Evaluating Impacts

B. Costs Associated With the Proposed 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 CO2 Emissions

H. Non-GHG Health and Environmental Impacts

I. Energy Security Impacts

J. Other Impacts

K. Summary of Costs and Benefits From the Greenhouse Gas Emissions Perspective

L. Summary of Costs and Benefits From the Fuel Efficiency Perspective

IX. Analysis of Alternatives

A. What are the alternatives that the agencies considered?

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

C. How would the agencies include commercial trailers, as described in alternative 7?

X. Recommendations From the 2010 NAS Report

A. Overview

B. What were the major findings and recommendations of the 2010 NAS report, and how is the proposed HD national program consistent with them?

XI. Statutory and Executive Order Reviews

XII. Statutory Provisions and Legal Authority

A. EPA

B. NHTSA

I. Overview

A. Introduction

EPA and NHTSA (“the agencies”) are announcing a first-ever program to reduce greenhouse gas (GHG) emissions and improve fuel efficiency 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, after light-duty passenger cars and trucks.

In a recent memorandum to the Administrators of EPA and NHTSA (and the Secretaries of Transportation and Start Printed Page 74156Energy), 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.” [4] Earlier this year, EPA and NHTSA established for the first time a national program to sharply reduce GHG emissions and fuel consumption from passenger cars and light trucks. Now, each agency is proposing rules that together would create a strong and comprehensive Heavy-Duty National Program (“HD National Program”) designed to address the urgent and closely intertwined challenges of dependence on oil, energy security, and global climate change. At the same time, the proposed program would enhance American competitiveness and job creation, benefit consumers and businesses by reducing costs for transporting goods, and spur growth in the clean energy sector.

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 a HD National Program based on a common set of principles. In the letters, the stakeholders commit 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 proposed HD National Program builds on many years of heavy-duty engine and vehicle technology development to achieve what the agencies believe would be the greatest degree of GHG emission and fuel consumption reduction appropriate, feasible, and cost-effective for the model years in question. Still, by proposing to take 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 GHG emissions and fuel consumption. For example, NHTSA and EPA have stopped short of proposing fuel consumption and GHG emissions standards for trucks based on use of hybrid powertrain technology. Similarly, we expect that 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 such opportunities emerge in the coming years, we expect that we will propose a second phase of provisions in the future to reinforce these developments and maximize the achieved reductions in GHG emissions and fuel consumption reduction for the mid- and longer-term time frame.

In the May 21 memorandum, the President 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 vehicles beginning with the 2014 model year (MY), with the aim of issuing a final rule by July 30, 2011.” This proposed rulemaking is consistent with this Presidential Memorandum, with each agency proposing rules under its respective authority that together comprise a coordinated and comprehensive HD National 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. Heavy-duty trucks [5] have always 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.[6] It also does not include motorcycles. Thus, in this notice, 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.[7] 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.” [8] NHTSA interprets this to include all segments of the heavy-duty category described above, except for recreational vehicles, such as motor homes, since recreational vehicles are not commercial.

Setting GHG emissions standards for the heavy-duty sector will help to address climate change, which is widely viewed as a significant long-term threat to the global environment. 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 Start Printed Page 74157observed global warming over the last 50 years.[9] The primary GHGs of concern are carbon dioxide (CO2), methane (CH4), nitrous oxide (N2 O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6). 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.[10] Mobile sources addressed in the recent 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.[11] Heavy-duty vehicles emit CO2, CH4, N2 O, and HFCs and are responsible for nearly 19 percent of all mobile source GHGs (nearly 6% of all U.S. GHGs) and about 25 percent of section 202(a) mobile source GHGs. For heavy-duty vehicles in 2007, CO2 emissions represented more than 99 percent of all GHG emissions (including HFCs).[12]

Setting fuel consumption standards for the heavy-duty sector, pursuant to NHTSA's EISA authority, will also improve our energy 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 60 percent of U.S. petroleum consumption. World crude oil production is highly concentrated, exacerbating the risks of supply disruptions and price shocks. Tight global oil markets led to prices over $100 per barrel in 2008, with gasoline reaching as high as $4 per gallon in many parts of the United States, causing financial hardship for many families and businesses. The export of U.S. assets 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.[13]

In developing this joint proposal, 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] While our discussions covered a wide range of issues and viewpoints, one widespread recommendation was that the two agencies should develop a common Federal program with consistent standards of performance regarding fuel consumption and GHG emissions. The HD National Program we are proposing in this notice is consistent with that goal. 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 are committed to continuing to work with California ARB throughout this rulemaking process to help ensure our final rules can lead to 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 proposing 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 proposed fuel consumption standards and EPA's proposed GHG standards would apply to manufacturers of the following types of heavy-duty vehicles and their engines; the proposed 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 recent light-duty vehicle rule establishing CAFE and GHG standards for MYs 2012-2016 light-duty vehicles, EPA's and NHTSA's proposed 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 CO2 tailpipe emissions. For all vehicles that consume carbon-based fuels, the amount of CO2 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 CO2 emitted into the air. The technologies available for improving fuel efficiency, and therefore for reducing both CO2 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 proposing under our separate legal authorities.

The timelines for the implementation of the proposed NHTSA and EPA standards are also closely coordinated. EPA's proposed GHG emission standards would 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 I.B.(5) below, NHTSA's proposed fuel consumption standards would be voluntary in model years 2014 and 2015, becoming mandatory in model year 2016, except for diesel engine standards which would be voluntary in model years 2014, 2015 and 2016, becoming mandatory in model year 2017. Both agencies are also allowing early compliance in model year 2013. A detailed discussion of how the proposed standards are consistent with each agency's respective statutory requirements and authorities is found later in this notice.

Neither EPA nor NHTSA is proposing 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. However, the agencies are considering proposing such standards in a future rulemaking, and request comment on such an action later in this preamble.

B. Building Blocks of the Heavy-Duty National Program

The standards that are being proposed in this notice represent the first time Start Printed Page 74158that NHTSA and EPA would regulate the heavy-duty sector for fuel consumption and GHG emissions, respectively. The proposed 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 (NOX). 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% less NOX and 99% 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 are projected to provide greater than $70 billion in health and welfare benefits annually in 2030 alone (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 highways. 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 proposed program incorporates the existing engine-based approach used for criteria emissions 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 economy of commercial medium-duty and heavy-duty on-highway vehicles and work trucks in three steps: A study by NAS, a study by NHTSA, and a rulemaking to develop the regulations themselves.[16]

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; [17] 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) [18] that have long governed NHTSA's setting of fuel economy standards for passenger cars and light trucks, although many of the same factors 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

As mandated by Congress in EISA, the National Research Council (NRC) under NAS recently 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.” [19] This study covers the same universe of heavy-duty vehicles that is the focus of this proposed 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. NHTSA's and EPA's detailed assessments of each of the relevant recommendations of the NAS Start Printed Page 74159report are discussed in Section X of this preamble and in the NHTSA HD study accompanying this notice of proposed rulemaking (NPRM).

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

On April 1, 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. The agencies have used the light-duty National Program as a model for this proposed 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 proposed standards and compliance structures, although in this proposal each agency proposes 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 to meet a closely coordinated Federal 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 CO2 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 draft 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 proposed 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 proposed standards. These include such approaches as improved logistics and driver training, as discussed in the draft 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, liberalizing 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 proposed standards and also provide benefits for the existing truck fleet, furthering the public policy objectives of addressing energy security and climate change.

(6.) Canada's Department of the Environment

The Government of Canada's Department of the Environment (Environment Canada) assisted EPA's development of this proposed rulemaking, by conducting emissions testing of heavy-duty vehicles at Environment Canada test facilities to gather data on a range of possible test cycles.

We expect the technical collaboration with Environment Canada to continue as we address issues raised by stakeholders in response to this NPRM, and as we continue to develop details of certain testing and compliance verification procedures. We may also be able to 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.

C. Summary of the Proposed 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).[20] 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 Start Printed Page 74160inherent efficiency of the engine as well as making changes to the vehicles to reduce the amount of work that the engine needs to do per mile traveled. This thus requires a focus on the entire vehicle. 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. The 2010 NAS Report recognized this need and recommended a complete-vehicle approach to regulation. As described elsewhere in this preamble, the proposed standards that make up the HD National Program aim to address the complete vehicle, to the extent practicable and appropriate under the agencies' respective statutory authorities, through complementary engine and vehicle standards, in order to reduce the complexity of the regulatory system and achieve the greatest gains as soon as possible.

(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.[21] Table I-1 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.

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.[22] 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. Commercial “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 proposed standards in careful consideration of the diversity and complexity of the heavy-duty truck industry, as discussed next.

(2) Summary of Proposed 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 proposing to divide 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 proposing related but distinct program approaches reflecting the specific challenges that we see for manufacturers in these segments. In the following paragraphs, we discuss EPA's proposed GHG emission standards and NHTSA's proposed fuel consumption standards for the three regulatory categories of heavy-duty vehicles and their engines.

The agencies are proposing 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 alternatively consider fuel consumption as the basis for its standards. As a result, for heavy-duty Start Printed Page 74161pickup trucks and vans, EPA and NHTSA are proposing standards on a per-mile basis (g/mile for the EPA standards, gallons/100 miles for the NHTSA standards), as explained in Section I.C.(2)(b) below. For heavy-duty trucks, both combination and vocational, the agencies are proposing standards expressed in terms of the key measure of freight movement, tons of payload miles or, more simply, ton-miles. Hence, for EPA the proposed 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 proposed 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 proposing 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 proposing 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 proposed 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.[23] 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 would involve improvements such as 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 separate from each other. 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 proposing standards for the tractors and their engines in this rulemaking, but are not proposing standards for trailers in this rulemaking. The agencies are requesting comment on potential standards for trailers, but will address standards for trailers in a separate rulemaking.

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 proposing 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 proposed standards to result in the application of improved technologies for lower GHG emissions and fuel consumption for both the cab and the engine.

Start Printed Page 74162

Accordingly, for Class 7 and 8 combination tractors, the agencies are each proposing two sets of standards. For vehicle-related emissions and fuel consumption, the agencies are proposing that tractor manufacturers meet respective vehicle-based standards. Compliance with the vehicle standard would 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 proposal. 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 would also assume the use of a representative typical engine, rather than a vehicle-specific engine, because engines are regulated separately and include an averaging, banking, and trading program separate from the vehicle program. The model and appropriate inputs would be used to quantify the overall performance of the vehicle in terms of CO2 emissions and fuel consumption. The model's development and design, as well as the sources for inputs and the evaluation of the model's accuracy, are discussed in detail in Section II below and in Chapter 4 of the draft RIA.

EPA and NHTSA also considered developing respective alternative standards based on the direct testing of the emissions and fuel consumption of the entire vehicle for this category of vehicles, as measured using a chassis test procedure. This would be similar to the proposed approach for standards for HD pickups and vans discussed below. The agencies believe that such an approach warrants continued consideration. However, the agencies are not prepared to propose chassis-test-based standards at this time, primarily because of the very small number of chassis-test facilities that currently exist, but rather are proposing only the tractor standards and the engine-based standards discussed above. The agencies seek comment on the potential benefits and trade-offs of chassis-test-based standards for combination tractors.

(1) Proposed Standards for Class 7 and 8 Combination Tractors

The vehicle standards that EPA and NHTSA are proposing 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 among these vehicles. The proposed 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.

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. Table I-2 presents the agencies' respective proposed standards for combination tractor manufacturers for the 2017 model year for illustration.

Start Printed Page 74163

In addition, the agencies are proposing separate performance standards for the engines manufactured for use in these trucks. EPA's proposed engine-based CO2 standards and NHTSA's proposed engine-based fuel consumption standards would vary based on the expected weight class and usage of the truck into which the engine would be installed. EPA is also proposing engine-based N2 O and CH4 standards for manufacturers of the engines used in combination tractors. EPA is proposing separate engine-based standards for these GHGs because the agency believes that N2 O and CH4 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. However, NHTSA is not incorporating standards related to these GHGs due to their lack of influence on fuel consumption. EPA expects that manufacturers of current engine technologies would be able to comply with the proposed “cap” standards with little or no technological improvements; the value of the standards would be to prevent significant increases in these emissions as alternative technologies are developed and introduced in the future. Compliance with the proposed EPA engine-based CO2 standards and the proposed NHTSA fuel consumption standards, as well as the proposed EPA N2 O and CH4 standards, would be determined using the appropriate EPA engine test procedure, as discussed in Section II below.

As with the other categories of heavy-duty vehicles, EPA and NHTSA are proposing respective standards that would apply to Class 7 and 8 trucks at the time of production (as in Table I-2, above). In addition, EPA is proposing separate standards that would apply for a specified period of time in use. All of the proposed standards for these trucks, as well as details about the proposed provisions for certification and implementation of these standards, are discussed in more detail in Sections II, III, IV, and V below and in the draft RIA.

(ii) EPA Proposed Air Conditioning Leakage Standard for Class 7 and 8 Combination Tractors

In addition to the proposed EPA tractor- and engine-based standards for CO2 and engine-based standards for N2 O, and CH4 emissions, EPA is also proposing a separate standard to reduce leakage of HFC refrigerant from cabin air conditioning systems from combination tractors, to apply to the tractor manufacturer. This standard would be independent of the CO2 tractor standard, as discussed below. Because the current refrigerant used widely in all these systems has a very high global warming potential, EPA is concerned about leakage of refrigerant over time.[25]

Because the interior volume to be cooled for most of these truck cabins is similar to that of light-duty trucks, the size and design of current truck A/C systems is also very similar. The proposed compliance approach for Class 7 and 8 tractors is therefore similar to that in the light-duty rule in that these proposed standards are design-based. Manufacturers would 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 proposed 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 CO2 g/mi standard, and EPA took into account the expected use of such credits in establishing the CO2 emissions standards. In this rule, EPA is proposing that manufacturers actually meet a standard—as opposed to having the opportunity to earn a credit—for A/C refrigerant leakage. Thus, for this rule, refrigerant leakage is not accounted for in the development of the proposed CO2 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 CO2 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 the expression of the leakage rate. The light-duty A/C leakage standard is expressed in terms of grams per year. For this heavy-duty rule, however, because of the wide variety of system designs and arrangements, a one-size-fits-all gram per year standard would likely be much less relevant, so EPA believes it is more appropriate to propose a standard in terms of percent of total refrigerant leakage per year. This requires the total refrigerant capacity of Start Printed Page 74164the A/C system to be taken into account in determining compliance. EPA believes that this proposed approach—a standard instead of a credit, and basing the standard on percent 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 would be determined through a showing by the tractor manufacturer that its A/C system incorporated a combination of low-leak technologies sufficient to meet the percent leakage of the standard. This proposed “menu” of technologies is very similar to that established in the light-duty GHG rule.[25]

Finally, EPA is not proposing 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 CO2 from a heavy-duty tractor as compared to those from a light-duty vehicle mean that the relative amount of CO2 that could be reduced through A/C efficiency improvements is very small. We request comment on this decision and whether EPA should reflect A/C system efficiency in the final program either as a credit or a stand-alone standard based on the same technologies and performance levels as the light-duty program.

A more detailed discussion of A/C related issues is found in Section II 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 program, and the agencies are not considering 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 this proposal as “HD pickups and vans”) together emit about 20 percent of today's GHG emissions from the heavy-duty vehicle sector.

About 90 percent of HD pickups and vans are 3/4-ton and 1-ton pick-up 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 propose 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 propose corresponding gallons per 100 mile fuel consumption standards that are likewise based on the whole vehicle. This complete vehicle approach being proposed 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 proposing, as detailed in Section II.C. These proposed 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 would 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).[27]

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).[28] 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 weight-based metric provides a better attribute than the footprint attribute utilized in the light-duty vehicle rulemaking. Weight-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 pick-up or van. EPA and NHTSA are therefore proposing standards for HD pickups and vans based on a “work factor” that combines their payload and towing capabilities, with an added adjustment for 4-wheel drive vehicles.

The agencies are proposing that each manufacturer's fleet average standard would be based on production volume-weighting of target standards for each vehicle that in turn are based on the vehicle's work factor. These target standards would be taken from a set of curves (mathematical functions), presented in Section II.C. EPA is also proposing that the CO2 standards be phased in gradually starting in the 2014 model year, at 15-20-40-60-100 percent in model years 2014-2015-2016-2017-2018, respectively. The phase-in would take the form of a set of target standard curves, with increasing stringency in each model year, as detailed in Section II.C. The EPA standards proposed 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. Section II.C also discusses the rationale behind the proposal of separate targets for diesel and gasoline vehicle standards. EPA is also proposing a manufacturer's alternative implementation schedule for Start Printed Page 74165model years 2016-2018 that parallels and is equivalent to NHTSA's first alternative described below.

NHTSA is proposing to allow manufacturers to select one of two fuel consumption standards alternatives for model years 2016 and later. To meet the EISA statutory requirement for three year regulatory stability, the first alternative would define individual gasoline vehicle and diesel vehicle fuel consumption target curves that would not change for model years 2016 and later. The proposed target curves for this alternative are presented in Section II.C. The second alternative would use target curves that are equivalent to the EPA program in each model year 2016 to 2018. 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 proposing, to rely on the same product plans to satisfy either of these two alternatives, and also EPA requirements. NHTSA is also proposing that manufacturers may 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 proposed EPA and NHTSA standard 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 would 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
  • Gasoline engine coupled cam phasing
  • 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 CO2 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 proposing that these vehicles generally be regulated as Class 2b through 8 vocational vehicles, as described in Section I.C(2)(c), because, like other vocational vehicles, we have little information on baseline aerodynamic performance and expectations for improvement. However, 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 proposing that these vehicles be included in the chassis-based HD pickup and van program. These proposed provisions are described in Section V.B.

In addition to proposed EPA CO2 emission standards and the proposed NHTSA fuel consumption standards for HD pickups and vans, EPA is also proposing standards for two additional GHGs, N2 O and CH4, as well as standards for air conditioning-related HFC emissions. These standards are discussed in more detail in Section II.E. Finally, EPA is proposing standards that would apply to HD pickups and vans in use. All of the proposed standards for these HD pickups and vans, as well as details about the proposed 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,[29] tow trucks, among others. These vehicles and their engines contribute approximately 15 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 are proposing that in this vocational vehicle category the chassis manufacturers be the focus of the proposed GHG and fuel consumption standards. They play a central role in the manufacturing process, and the product they produce—the chassis with engine and transmissions—includes the primary technologies that affect emissions and fuel consumption. They also constitute a much more limited group of manufacturers for purposes of developing a regulatory program. In contrast, a focus on the body manufacturers would be much less practical, since they represent a much more diverse set of manufacturers, and the part of the vehicle that they add has a very limited impact on opportunities to reduce GHG emissions and fuel consumption (given the limited role that aerodynamics plays in the types of lower speed operation typically found with vocational vehicles). Therefore, the proposed 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 request comment on our proposed focus on chassis manufacturers.

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 proposing two sets of standards for Class 2b-8 vocational vehicles. For vehicle-related emissions and fuel consumption, the agencies are proposing standards for chassis manufacturers: EPA CO2 (g/ton-mile) standards and NHTSA fuel consumption (gal/1,000 ton-mile) standards). Also as in the case of Class 7 and 8 tractors, we propose to use GEM, a customized vehicle simulation model, to determine compliance with the vocational vehicle standards. The primary manufacturer-generated input Start Printed Page 74166into the proposed compliance model for this category of trucks would 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. The model would also assume the use of a typical representative engine in the simulation, resulting in an overall value for CO2 emissions and one for fuel consumption. As is the case for combination tractors, the manufacturers of the engines intended for vocational vehicles would be subject to separate engine-based standards.

(i) Proposed Standards for Class 2b-8 Vocational Vehicles

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, as proposed for combination tractors, EPA and NHTSA are proposing separate standards for the manufacturers of engines used in Class 2b-8 vocational vehicles. EPA's proposed engine-based CO2 standards and NHTSA's proposed engine-based fuel consumption standards would vary based on the expected weight class and usage of the truck into which the engine would be installed. The agencies propose to use the groupings EPA currently uses for other heavy-duty engine standards—light heavy-duty, medium heavy-duty, and heavy heavy-duty, as discussed in Section II below.

Tire rolling resistance is closely related to the weight of the vehicle. Therefore, we propose that the vehicle-based standards for these trucks vary according to one key attribute, GVWR. For this initial HD rulemaking, we propose that these standards be 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 proposed vehicle-based standards because they parallel the general divisions among key engine characteristics, as discussed in Section II.

The agencies intend to monitor the development of and production feasibility of new vehicle-related GHG and fuel consumption reduction improving technologies and consider including these technologies in future rulemakings. As discussed below, 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. We also are proposing a mechanism whereby credits can be generated by use of other technologies not included in the compliance model. (See Sections I.E and IV below.)

Table I-3 presents EPA's proposed CO2 standards and NHTSA's proposed fuel consumption standards for chassis manufacturers of Class 2b through Class 8 vocational vehicles for the 2017 model year for illustrative purposes.

At this time, NHTSA and EPA are not prepared to propose alternative standards based on a whole-vehicle chassis test for vocational vehicles in this initial heavy-duty rulemaking. As discussed above for combination tractors, the primary reason is the very small number of chassis-test facilities that currently exist. Thus, the agencies are proposing only the compliance-model based standards and engine standards discussed above, and seek comment on the appropriateness of chassis-test-based standards for the vocational vehicle category.

For vocational vehicles using hybrid technology, the agencies are proposing two specialized approaches to allow manufacturers to gain credit for the emissions and fuel consumption reductions associated with hybrid technology. One option to account for the reductions associated with vocational vehicles using hybrid technology would compare vehicle-based chassis tests with and without the hybrid technology. The other option would allow a manufacturer to simulate the operation of the hybrid system in an engine-based test. The options are further discussed in Section IV.

The proposed program also provides for opportunities to generate credits for technologies not measured by the GEM, again described more fully in Section IV.

As mentioned above for Class 7 and 8 combination tractors, EPA believes that N2 O and CH4 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 is not proposing separate vehicle-based standards for these GHGs, but is proposing engine-based N2 O and CH4 standards for manufacturers of the engines to be used in vocational vehicles. EPA expects that Start Printed Page 74167manufacturers of current engine technologies would be able to comply with the proposed “cap” standards with little or no technological improvements; the value of the standards would be in that they would prevent significant increases in these emissions as alternative technologies are developed and introduced in the future. Compliance with the proposed EPA engine-based CO2 standards and the proposed NHTSA fuel consumption standards, as well as the proposed EPA N2 O and CH4 standards, would 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 proposing standards that would apply to Class 2b-8 vocational vehicles at the time of production, and EPA is proposing standards for a specified period of time in use. All of the proposed standards for these trucks, as well as details about the proposed provisions for certification and implementation of these standards, are discussed in more detail later in this notice and in the draft RIA.

EPA is not proposing A/C refrigerant leakage standards for Class 2b-8 vocational vehicles at this time, 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. EPA requests comment on how A/C standards might practically be applied to manufacturers of vocational vehicles.

(d) What Manufacturers Are Not Covered by the Proposed Standards?

EPA and NHTSA are proposing to temporarily defer the proposed 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. We are not aware of any manufacturers of HD pickups and vans that meet these criteria. For each of the other categories and for engines, we have identified a small number of manufacturers that would appear to qualify as small businesses. The production of these companies is small, and we believe 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. We request comment on our assumption that the impact of these exemptions for small businesses will be small and further whether it will be possible to circumvent the regulations by creating new small businesses to displace existing manufacturers. We discuss the specific deferral provisions 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.

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

This section summarizes the projected costs and benefits of the proposed NHTSA fuel consumption and EPA GHG emissions standards. These projections help to inform the agencies' choices among the alternatives considered and provide further confirmation that the proposed 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 and benefits of the proposed GHG and fuel consumption standards. Table I-4 shows estimated lifetime discounted costs, benefits and net benefits for all heavy-duty vehicles projected to be sold in model years 2014-2018. These figures depend on estimated values for the social cost of carbon (SCC), as described in Section VIII.G.

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Table I-5 shows the estimated lifetime reductions in CO2 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-5 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-5 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 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 CO2 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 CO2, in 2008 dollars and 2010 emissions. Table I-6 presents benefits based on the $22 value. Section VIII.F presents the four marginal values used to estimate monetized benefits of CO2 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 fuel savings, energy security, and other externalities such as reduced accidents, congestion and noise. However, the analysis supporting the proposal omits other impacts such as benefits related to non-GHG emission reductions. The lifetime discounted benefits are shown for one of four different SCC values considered by EPA and NHTSA. The values in Table I-6 do not include costs associated with new technology required to meet the GHG and fuel consumption standards.

Table I-7 shows the agencies' estimated lifetime fuel savings, lifetime CO2 emission reductions, and the monetized net present values of those fuel savings and CO2 emission reductions. The gallons of fuel and CO2 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 CO2 shown in Table I-7 are totals for the five model years throughout their projected lifetime and are not discounted. The monetized values shown in Table I-7 are the summed values of the discounted monetized-fuel consumption and Start Printed Page 74169monetized-CO2 reductions for the five model years 2014-2018 throughout their lifetimes. The monetized values in Table I-7 reflect both a 3 percent and a 7 percent discount rate as noted.

Table I-8 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-8 are for the industry as a whole and do not account for fuel savings associated with the program.

Table I-9 shows EPA's estimated incremental cost increase of the average new heavy-duty vehicles for each model year 2014-2018. The values shown are incremental to a baseline vehicle and are not cumulative.

E. Program Flexibilities

For each of the heavy-duty vehicle and heavy-duty engine categories for which we are proposing respective standards, EPA and NHTSA are also proposing provisions designed to give manufacturers a degree of flexibility in complying with the standards. These proposed provisions have enabled the agencies to consider overall standards that are more stringent and that would 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.[30] 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 proposed flexibility provisions are essentially identical to each other in structure and function. For combination tractor and vocational vehicle categories and for heavy-duty engines, we are proposing 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 proposed ABT provisions are patterned on existing EPA ABT programs and would allow a vehicle manufacturer to reduce CO2 emission and fuel consumption levels Start Printed Page 74170further than the level of the standard for one or more vehicles to generate ABT credits. The manufacturer could then use those credits to offset higher emission or fuel consumption levels in other similar vehicles, “bank” the credits for later use, or “trade” the credits to another manufacturer. We are proposing similar ABT provisions for manufacturers of heavy-duty engines. For HD pickups and vans, we are proposing a fleet averaging system very similar to the light-duty GHG and CAFE fleet averaging system.

To best ensure that the overall emission and fuel consumption reductions of the program would be achieved and to minimize any effect on the ability of the market to respond to consumer needs, the agencies propose to restrict the use of averaging to limited sets of vehicles and engines expected to have similar emission or fuel consumption characteristics. For example, averaging would be allowed among Class 7 low-roof day cab vehicles, but not among those vehicles and Class 8 sleeper cabs or vocational vehicles. Also, we propose that credits generated by vehicles not be applicable to engine compliance, and vice versa. For HD pickups and vans, we propose that fleet averaging be allowed with minimum restriction within the HD pickup and van category.

In addition to ABT, the agencies are proposing that a manufacturer that reduces CO2 emissions and fuel consumption below required levels prior to the beginning of the program be allowed to generate the same number of credits (“early credits”) that they would after the program begins.

The agencies are also proposing that manufacturers that show improvements in CO2 emissions and fuel consumption and incorporate certain technologies (including hybrid powertrains, Rankine engines, or electric vehicles) be eligible for special “advanced technology” credits. Unlike other credits in this proposal, the advanced technology credits could be applied to any heavy-duty vehicle or engine, and not be limited to the vehicle category generating the credit.

The technologies eligible for advanced technology credits above lend themselves to straightforward methodologies for quantifying the emission or fuel consumption reductions. For other technologies which can reduce CO2 and fuel consumption, but for which there do not yet exist established methods for quantifying reductions, the agencies still seek to encourage the development of such innovative technologies, and are therefore proposing special “innovative technology” credits. These innovative technology credits would 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. Manufacturers would need to quantify the reductions in fuel consumption and CO2 emissions that the technology could achieve, above and beyond those achieved on the existing test procedures. As with ABT, we propose that the use of innovative technology credits be only allowed among vehicles and engines expected to have similar emissions and fuel consumption characteristics (e.g., within each of the nine Class 7 & 8 combination tractor subcategories, or within each of the three Class 2b-8 vocational vehicle subcategories).

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 proposal implements a specific provision from Title II, section 202(a).[31] 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 for greenhouse gases, section 202(a) authorizes 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 Start Printed Page 74171F.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 the 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)). 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’ ”). Also see 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)).

(b) 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 CO2 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

EISA authorizes NHTSA to create a fuel efficiency improvement program for “commercial medium- and heavy-duty on-highway vehicles and work trucks” [32] 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.

Since this is the first rulemaking that NHTSA has conducted under 49 U.S.C. 32902(k)(2), the agency must interpret these elements and factors in the context of setting standards, choosing metrics, and determining test methods and compliance/enforcement mechanisms. 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. section 32902(k). See 49 U.S.C. section 32902(b)(1). We note that 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. section 32902(b)(3)(B). For purposes of the fuel efficiency standards that the agency is proposing for HD vehicles and engines, NHTSA believes that one permissible reading of the statute is that Congress did not intend for the 5-year maximum limit to apply to standards promulgated in accordance with 49 U.S.C. section 32902(k), given the language in Start Printed Page 7417232902(b)(1). Based on this interpretation, NHTSA proposes 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 seeks comment on this interpretation of EISA.

(a) NHTSA Testing Authority

49 U.S.C. 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.

(b) NHTSA Enforcement Authority

49 U.S.C. 32902(k)(2) also states that NHTSA must adopt and implement appropriate, cost-effective, and technologically feasible compliance and enforcement protocols for the fuel efficiency improvement program.

In 49 U.S.C. 32902(k)(2), Congress did not speak directly to the “compliance and enforcement protocols” it envisioned. Instead, it left the matter generally to the Secretary. Congress' approach is unlike CAFE enforcement for passenger cars and light trucks, where Congress specified a program where a manufacturer either complies with standards or pays civil penalties. But Congress did not specify in 49 U.S.C. 32902(k) what it precisely meant in directing NHTSA to develop “compliance and enforcement protocols.” It appears, therefore, that Congress has assigned this matter to the agency's discretion.

The statute is silent with respect to how “protocol” should be interpreted. The term “protocol” is imprecise. 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).[33] 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 interprets “protocol” in the context of EISA as authorizing the agency to determine both whether manufacturers have complied with the standards, and to establish the enforcement mechanisms and decision criteria for non-compliance. NHTSA seeks comment on its interpretation of this statutory requirement.

G. Future HD GHG and Fuel Consumption Rulemakings

This proposal 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 propose 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 timeframe, our proposal is very aggressive—with limited lead time compared to historic heavy-duty regulations—but pragmatic in the context of technologies that are available.

While we are now only proposing this first step, it is worthwhile to consider how future regulations that may follow this step may be constructed. 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 would not be necessary to meet the proposed standards, which are premised on the use of existing technologies. When we begin our future 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 proposing 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 and GHG emissions. However, we believe the important issues and technical work related to setting new criteria emissions standards appropriate for the World Harmonized Duty Cycle are significant and beyond the scope of this rulemaking. Therefore, the agencies are not proposing to adopt these test procedures in this proposal, but we are ready to work with interested stakeholders to adopt these procedures in a future action.

As with this proposal, 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.Start Printed Page 74173

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

This section describes the standards and implementation dates that the agencies are proposing for the three categories of heavy-duty vehicles. The agencies have performed a technology analysis to determine the level of standards that we believe would be appropriate, cost-effective, and feasible during the rulemaking timeframe. This analysis, described in Section III and in more detail in the draft RIA Chapter 2, considered:

  • The level of technology that is incorporated in current new trucks,
  • The available data on corresponding CO2 emissions and fuel consumption for these vehicles,
  • Technologies that would reduce CO2 emissions and fuel consumption and that are judged to be feasible and appropriate for these vehicles through 2018 model year,
  • The effectiveness and cost of these technologies,
  • Projections of future U.S. sales for trucks, and
  • Forecasts of manufacturers' product redesign schedules.

A. What vehicles would be affected?

EPA and NHTSA are proposing standards for heavy-duty engines and also for what we refer to generally as “heavy-duty trucks.” As noted in Section I, for purposes of this preamble, the term “heavy-duty” or “HD” is used to apply 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 proposed 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.[34] 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.[35] Therefore, the term “heavy-duty trucks” in this proposal refers to both work trucks and commercial medium- and heavy-duty on-highway vehicles as defined by EISA. Heavy-duty engines affected by the proposed standards are those that are installed in commercial medium- and heavy-duty trucks, 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. EPA is proposing to include recreational on-highway vehicles within their rulemaking, while NHTSA is limiting their scope to commercial trucks which would not include these vehicles.

EPA and NHTSA are proposing standards for each of the following categories, which together comprise all heavy-duty vehicles and all engines used in such vehicles.[36] In order to most appropriately regulate the broad range of heavy-duty vehicles, the agencies are proposing to set separate engine and vehicle standards for the combination tractors and the Class 2b through 8 vocational vehicles and the engines installed in them. The engine standards and test procedures for engines installed in the tractors and vocational vehicles are discussed within the applicable vehicle sections.

  • Class 7 and 8 Combination Tractors.
  • Heavy-Duty Pickup Trucks and Vans.
  • Class 2b through 8 Vocational Vehicles.

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

B. Class 7 and 8 Combination Tractors

EPA is proposing CO2 standards and NHTSA is proposing fuel consumption standards for new Class 7 and 8 combination tractors. The standards are for the tractor cab, with a separate standard for the engines that are installed in the tractor. Together these standards would achieve reductions up to 20 percent from tractors. As discussed below, EPA is proposing to adopt the existing useful life definitions for heavy-duty engines for the Class 7 and 8 tractors. NHTSA is proposing fuel consumption standards for tractors, and engine standards for heavy-duty engines for Class 7 and 8 tractors. The agencies' analyses, as discussed briefly below and in more detail later in this preamble and in the draft RIA Chapter 2, show that these standards are appropriate and feasible under each agency's respective statutory authorities.

EPA is also proposing standards to control N2 O, CH4, and HFC emissions from Class 7 and 8 combination tractors. The proposed heavy-duty engine standards for both N2 O and CH4 and details of the standard are included in the discussion in Section II. The proposed air conditioning leakage standards applying to tractor manufacturers to address HFC emissions are included in Section II.

The agencies are proposing CO2 emissions and fuel consumption standards for the combination tractors that will focus on reductions that can be achieved through improvements in the tractor (such as aerodynamics), tires, and other vehicle systems. The agencies are also proposing heavy-duty engine standards for CO2 emissions and fuel consumption that would focus on potential technological improvements in fuel combustion and overall engine efficiency.

The agencies have analyzed the feasibility of achieving the CO2 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 Start Printed Page 74174standards in Section III. In developing the proposed 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 CO2 and fuel savings that may be achieved.

EPA and NHTSA are proposing attribute-based standards for the Class 7 and 8 combination tractors, or, put another way, we are proposing to set 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 CO2 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 recent light-duty vehicle fuel economy and GHG rule, in which the standards are based on the attribute of vehicle “footprint,” the existing heavy-duty highway engine criteria pollutant emission standards for many years have been based on a vehicle weight attribute (Light Heavy, Medium Heavy, Heavy Heavy) with different useful life periods, which is the same approach proposed for the engine GHG and fuel consumption standards discussed below.

Heavy-duty combination tractors are built to move freight. The ability of a truck 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 combined 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 80,000 pound GCWR. Consistent with the recommendation in the National Academy of Sciences 2010 Report to NHTSA,[37] the agencies are proposing 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 trucks have better specific fuel consumption and GHG emissions than lower payload capacity trucks. Therefore, since the amount of payload that a Class 7 truck can carry is less than the Class 8 truck'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 proposing separate standards for Class 7 and Class 8 tractors.

The agencies are not proposing to set 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 is 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 vehicle 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 proposing that the roof height of the tractor determine the trailer type required to be used to demonstrate compliance of a truck with the fuel consumption and CO2 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 customarily tied 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.[38] Therefore, Start Printed Page 74175some 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 proposing to create separate standards for sleeper cabs and day cabs.

To account for the relevant combinations of these attributes, the agencies therefore propose to segment 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

The agencies have not identified any Class 7 or Class 8 day cabs with mid roof heights in the market today but welcome comments with regard to this market characterization.

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. The agencies propose to treat tractors with adjustable roof fairings as low roof tractors and test with the fairing down. The agencies welcome comments on this approach and data to support whether to allow additional credits for their use.

The agencies are proposing to classify all vehicles with sleeper cabs as tractors. The proposed rules would not allow vehicles with sleeper cabs to be classified as vocational vehicles. This provision is intended prevent the initial manufacture of straight truck vocational vehicles with sleeper cabs that, soon after introduction into commerce, would be converted to combination tractors, as a means to circumvent the Class 8 sleeper cab regulations. The agencies welcome comments on the likelihood of manufacturers using such an approach to circumvent the regulations and the appropriate regulatory provisions the agencies should consider to prevent such actions.

(1) What are the proposed Class 7 and 8 tractor and engine CO2 emissions and fuel consumption standards and their timing?

In developing the proposed tractor and engine standards, 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 engines, the associated lead time, the associated costs for the industry, fuel savings for the consumer, and the magnitude of the CO2 and fuel savings that may be achieved. The technologies that the agencies considered while setting the proposed tractor standards include improvements in aerodynamic design, lower rolling resistance tires, extended idle reduction technologies, and vehicle empty weight reduction. The technologies that the agencies considered while setting the engine standards include engine friction reduction, aftertreatment optimization, and turbocompounding, among others. The agencies' evaluation indicates that these technologies are available today, but have very low application rates in the market. The agencies have analyzed the technical feasibility of achieving the proposed CO2 and fuel consumption standards for tractors and engines, based on projections of what actions manufacturers would be expected to take to reduce emissions and fuel consumption to achieve the standards. 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 draft RIA Chapter 2.

(a) Tractor Standards

The agencies are proposing the following standards for Class 7 and 8 combination tractors in Table II-1, using the subcategorization approach just explained. As noted, the agencies are not aware of any mid roof day cab tractors at this time, but are proposing that any Class 7 and 8 day cabs with a mid roof would meet the respective low roof standards, based on the similarity in baseline performance and similarity in expected improvement of mid roof sleeper cabs relative to low roof sleeper cabs.

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 proposing standards starting for that model year predicated on performance of those technologies. EPA is proposing more stringent tractor standards for the 2017 model year which reflect the CO2 emissions reductions required through the 2017 model year engine standards. (As explained in Section II.B.(2)(h)(v) below, engine performance is one of the inputs into the proposed 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 proposed standards apply throughout the useful life period as described in Section V. Similar to EPA's non-GHG standards approach, manufacturers may generate and use credits from Class 7 and 8 combination tractors to show compliance with the standards.

NHTSA is proposing 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 and stability requirement within EISA. NHTSA is also proposing new standards for the 2017 model year which reflect additional improvements in only the heavy-duty engines. While NHTSA proposes to 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 currently anticipated there will be notable deterioration of fuel consumption over the useful life. NHTSA believes that the vehicle and engine standards proposed for combination tractors are appropriate, cost-effective, and technologically feasible in the rulemaking timeframe based on our analysis detailed below in Section III and in the Chapter 2 of the draft RIA.

EPA and NHTSA are not proposing to make the 2017 vehicle standards more stringent based on the application of additional truck technologies because projected application rates of truck technologies used in setting the 2014 model year truck standard already reflect the maximum application rates we believe appropriate for these vehicles given their specific use patterns as described in Section III. We considered setting more stringent standards for Class 7 and 8 tractors based on the application of more advanced aerodynamic systems, such as self-compensating side extenders or other advanced aerodynamic technologies, but concluded that those Start Printed Page 74176technologies would not be fully developed in the necessary lead time. We request comment on this decision, supported by data as appropriate.

Based on our analysis, the 2017 model year standards represent up to a 20 percent reduction in CO2 emissions and fuel consumption over a 2010 model year baseline, as detailed in Section III.A.2.

(i) Off-Road Tractor Standards

In developing the proposal EPA and NHTSA received comment from manufacturers and owners that tractors sometimes have very limited on-road usage. These trucks are defined to be motor vehicles under 40 CFR 85.1703, but they will spend the majority of their operations off-road. Tractors, such as those used in oil fields, will experience little benefit from improved aerodynamics and low rolling resistance tires. The agencies are therefore proposing to allow a narrow range of these de facto off-road trucks to be excluded from the proposed tractor standards because the trucks do not travel at speeds high enough to realize aerodynamic improvements and require special off-road tires such as lug tires. The trucks must still use a certified engine, which will provide fuel consumption and CO2 emission reductions to the truck in all applications. To ensure the limited use of these trucks, the agencies are proposing requirements that the vehicles have off-road tires, have limited high speed operation, and are designed for specific off-road applications.[40] The agencies are proposing that a truck must meet the following requirements to qualify for an exemption from the vehicle standards for Class 7 and 8 tractors:

  • Installed tires which are lug tires or contain a speed rating of less than or equal to 60 mph; and
  • Include a vehicle speed limiter governed to 55 mph, and
  • Contain Power Take-Off controls, or have axle configurations other than 4x2, 6x2, or 6x4 and has GVWR greater than 57,000 pounds; and
  • Has a frame Resisting Bending Moment greater than 2,000,000 lb-in.[41]

EPA and NHTSA have concluded that the onroad performance losses and additional costs to develop a truck which meets these specifications will limit the exemption to trucks built for Start Printed Page 74177the desired purposes.[42] The agencies welcome comment on the proposed requirements and exemptions.

(b) Engine Standards

EPA is proposing GHG standards and NHTSA is proposing fuel consumption standards for new heavy-duty engines. The standards will vary depending on the type of vehicle in which they are used, as well as whether the engines are diesel or gasoline powered. This section discusses the standards for engines used in Class 7 and 8 combination tractors and also provides some overall background information. More information is also provided in the discussion of the standards for engines used in vocational vehicles.

EPA's existing criteria pollutant emissions regulations for heavy-duty highway engines establish four regulatory categories that represent the engine's intended and primary truck application.[43] 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 regulatory subcategory. The engines in these four regulatory subcategories range in size between approximately five liters and sixteen liters. The agencies welcome comments on updating the definitions of each subcategory, such as the typical horsepower levels, as described in 40 CFR 1036.140.

For the purposes of the GHG engine emissions and engine fuel consumption standards that EPA and NHTSA are proposing, the agencies intend to maintain these same four regulatory subcategories. This class structure would enable the agencies to set standards that appropriately reflect the technology available for engines for use in each type of vehicle, and that are therefore technologically feasible for these engines. This section discusses the MHD and HHD diesel engines used in Class 7 and 8 combination tractors. Additional details regarding the other heavy-duty engine standards are included in Section II.D.1.b.

EPA's proposed heavy-duty CO2 emission standards for diesel engines installed in combination tractors are presented in Table II-2. We should note that this does not cover gasoline or LHDD engines as they are not used in Class 7 and 8 combination tractors. Similar to EPA's non-GHG standards approach, manufacturers may generate and use credits to show compliance with the standards. EPA is proposing to adopt the existing useful life definitions for heavy-duty engines. The EPA standards would become effective in the 2014 model year, with more stringent standards becoming effective in model year 2017. Recently, EPA's heavy-duty highway engine program for criteria pollutants provided new emissions standards for the industry in three year increments. Largely, the heavy-duty engine and truck manufacturer product plans have fallen into three year cycles to reflect this regulatory environment. The proposed two-step CO2 emission standards recognize the opportunity for technology improvements over this timeframe while reflecting the typical diesel truck manufacturers' product plan cycles.

With respect to the lead time and cost of incorporating technology improvements that reduce GHG emissions and fuel consumption, EPA and NHTSA place important weight on the fact that during MYs 2014-2017 engine manufacturers are expected to redesign and upgrade their products. 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 proposed GHG and fuel consumption reductions, and to do this as part of the normal engine redesign process. This is an important aspect of the proposed 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. 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.

NHTSA's fuel consumption standards, also presented in Table II-2, would contain voluntary engine standards starting in 2014 model year, with mandatory engine standards starting in 2017 model year, harmonized with EPA's 2017 model year standards. A manufacturer may opt-in to NHTSA's voluntary standards in 2014, 2015 or 2016. Once a manufacturer opts-in, the standards become mandatory for the opt-in and subsequent model years, and the manufacturer may not reverse its decision. To opt into the program, a manufacturer must declare its intent to opt in to the program at the same time it submits the Pre-Certification Compliance Report. See 49 CFR 535.8 for information related to the Pre-Certification Compliance Report. A manufacturer opting into the program would begin tracking credits and debits beginning in the model year in which they opt into the program.

Start Printed Page 74178

Combination 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 would be required to meet the standard based on the steady-state SET test cycle, as discussed further in Section II.B(2)(i).

The baseline HHD diesel engine performance in 2010 model year on the SET is 490 g CO2/bhp-hr (4.81 gal/100 bhp-hr), as determined from 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 518 g CO2/bhp-hr (5.09 gallon/100-bhp-hr) in the 2010 model year. Further discussion of the derivation of the baseline can be found in Section III The diesel engine standards that EPA is proposing and the voluntary standards being proposed by NHTSA for the 2014 model year would require diesel engine manufacturers to achieve on average a three percent reduction in fuel consumption and CO2 emissions over the baseline 2010 model year performance for the engines. The agencies' assessment of the findings of the 2010 NAS Report and other literature sources indicates that there are technologies available to reduce fuel consumption by this level in the proposed timeframe. These technologies include improved turbochargers, aftertreatment optimization, low temperature exhaust gas recirculation, and engine friction reductions. Additional discussion on technical feasibility is included in Section III below and in draft RIA Chapter 2.

Furthermore, the agencies are proposing that diesel engines further reduce fuel consumption and CO2 emissions from the 2010 model year baseline in 2017 model year. The proposed reductions represent on average a six percent reduction for MHD and HHD diesel engines required to use the SET-based standard. The additional reductions could likely be achieved through the increased refinement of the technologies projected to be implemented for 2014, plus the addition of turbocompounding or other waste heat recovery systems. The agencies' analysis indicates that this type of advanced engine technology would require a longer development time than the 2014 model year, and we therefore are proposing to provide additional lead time to allow for its introduction.

The agencies are aware that some truck and engine manufacturers would prefer to align their product development plans for these engine standards with their current plans to meet Onboard Diagnostic regulations for EPA and California in 2013 and 2016. We believe our proposed averaging, banking and trading provisions already provide these manufacturers with considerable flexibility to manage their GHG compliance plans consistent with the 2013 model year. Nevertheless, we are requesting comment on whether EPA and NHTSA should provide additional defined phase-in schedules that would more explicitly accommodate this request. For example, we request comment on a phase-in schedule with a standard of 485 g/bhp-hr for the model years 2013-2015 followed by a standard of 460 g/bhp-hr for 2016-18 model years with the associated fuel consumption values for the NHTSA program. This phase-in schedule is just one of many potential schedules that would provide identical fuel savings and emissions reductions for the period from 2013-2018. If commenters wish to discuss a different phase-in schedule than the one proposed by the agencies, we request that commenters include a description of their preferred phase-in schedule, including an analysis showing that it would be at least as effective (or more) as the primary program for the period through the 2018 model year. We also request comment on whether similar provisions should be made for the vocational engine standards discussed later in this section.

In proposing this standard for heavy-duty diesel engines used in Class 7 and 8 combination tractors, the agencies have examined the current performance levels of the engines across the fleet. EPA and NHTSA found that a large majority of the engines were generally relatively close to the average baseline, with some above and some below. We recognize, however, that when regulating a category of engines for the first time, there will be individual products that may deviate significantly from this baseline level of performance. For the current fleet there is a relatively small group of engines that are significantly worse than the average baseline for other engines. In proposing the standards, the agencies have looked primarily at the typical performance levels of the majority of the engines in the fleet, and the increased performance that would be achieved through increased spread of technology. The agencies also recognize that for the smaller group of products, the same reduction from the industry baseline may experience significant issues of available lead-time and cost because these products may require a total redesign in order to meet the standards. These are limited instances where certain engine families have high atypically high baseline CO2 levels and limited line of engines across which to average performance. See 75 FR 25414-25419, which adopts temporary lead time allowance alternative standards to Start Printed Page 74179deal with a similar issue for a subset of light-duty vehicles. To accommodate these situations, the agencies are proposing a regulatory alternative whereby a manufacturer, for a limited period, 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, rather than meeting the otherwise-applicable standard 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. We do not believe this alternative needs to continue past the 2016 model year since manufacturers will have had ample opportunity to benchmark competitive products during redesign cycles and to make appropriate changes to bring their product performance into line with the rest of the industry. This alternative would not be available unless and until a manufacturer had exhausted all available credits and credit opportunities, and engines under the alternative standard could not generate credits. We are proposing that manufacturers can select engine families for this alternative standard without agency approval, but are proposing to require that manufacturers notify the agency of their choice and to include in that notification a demonstration that it has exhausted all available credits and credit opportunities.

The agencies are also requesting comment on the potential to extend this regulatory alternative for one additional year for a single engine family with performance measured in that year as six percent beyond the engine's own 2011 baseline level. We also request comment on the level of reduction beyond the baseline that is appropriate in this alternative. The three percent level reflects the aggregate improvement beyond the baseline we are requiring of the entire industry. As this provision is intended to address potential issues for legacy products that we would expect to be replaced or significantly improved at the manufacturer's next product redesign, we request comment if a two percent reduction would be more appropriate. We would consider two percent rather than three percent if we were convinced that making all of the changes we have outlined in our assessment of the technical feasibility of the standards was not possible for some engines due to legacy design issues that will change in the future. We are proposing that manufacturers making use of these provisions would need to exhaust all credits within this subcategory prior to using this flexibility and would not be able to generate emissions credits from other engines in the same regulatory subcategory as the engines complying using this alternate approach.

EPA and NHTSA considered setting even more stringent engine standards for the 2017 model year based on the use of more sophisticated waste heat recovery technologies such as bottoming cycle engine designs. We are not proposing more stringent standards because we do not believe this technology can be broadly available by 2017 model year. We request comment on the technological feasibility and cost-effectiveness of more stringent standards in the timeframe of the proposed standards.

(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 proposing would apply to individual vehicles and engines. NHTSA is not proposing to adopt in-use.

EPA is proposing 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. EPA is proposing a 2 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. Details on the development of the adjustment factor are included in draft RIA Chapter 3.

EPA is also proposing 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 proposes that the existing engine useful life periods, as included in Table II-3:, be broadened to include CO2 emissions and fuel consumption for both engines and tractors (see 40 CFR 86.004-2).

EPA and NHTSA request comments on the magnitude and need for an in-use adjustment factor for the engine standard and the compliance model (GEM) based tractor standard.

(2) Test Procedures and Related Issues

The agencies are proposing a complete set of test procedures to evaluate fuel consumption and CO2 emissions from Class 7 and 8 tractors and the engines installed in them. The test procedures related to the tractors are all new, while the engine test procedures build substantially on EPA's current non-GHG emissions test procedures, except as noted. This section discusses the proposed simulation model developed for demonstrating compliance with the tractor standard and the proposed engine test procedures.

(a) Truck Simulation Model

We are proposing to set separate engine and vehicle-based emission standards to achieve the goal of reducing emissions and fuel consumption for both trucks and engines. For the Class 7 and 8 tractors, engine manufacturers would be subject to the engine standards, and Class 7 and 8 tractor manufacturers would be required to install engines in their tractors certified for use in the tractor. The tractor manufacturer would be subject to a separate vehicle-based standard that would use a proposed truck simulation model to evaluate the Start Printed Page 74180impact 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.

NHTSA and EPA are proposing to evaluate fuel consumption and CO2 emissions respectively through a simulation of whole-vehicle operation, consistent with the NAS recommendation to use a truck model to evaluate truck performance. The agencies developed the Greenhouse gas Emissions Model (GEM) for the specific purpose of this proposal 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 agencies and proposed 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 draft 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 welcome comments on other simulation tools which could be used by the agencies. The use criteria for this model are that it must be able to be managed by the agencies for compliance purposes, has no cost to the end-user, is freely available and distributable as an executable file, contains open source code to provide transparency in the model's operation yet contains features which cannot be changed by the user, and is easy to use by any user with minimal or no prior experience.

GEM is designed to focus on the inputs most closely associated with fuel consumption and CO2 emissions—i.e., on those which have the largest impacts such as aerodynamics, rolling resistance, weight, and others.

EPA has validated GEM based on the chassis test results from a SmartWay certified tractor tested at Southwest Research Institute. The validation work conducted on these three vehicles is 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 CO2 emissions within 4 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 proposing to utilize in compliance testing. Test to test variation for heavy-duty vehicle chassis testing can be higher than 4 percent based on driver variation. The proposed simulation model is described in greater detail in Chapter 4 of the draft RIA and is available for download by interested parties at (http://www.epa.gov/​otaq/​climate/​regulations.htm). We request comment on all aspects of this approach to compliance determination in general and to the use of the GEM in particular.

The agencies are proposing that for demonstrating compliance, a Class 7 and 8 tractor manufacturer would measure the performance of specified tractor systems (such as aerodynamics and tire rolling resistance), input the values into GEM, and compare the model's output to the standard. The agencies propose that a tractor manufacturer would provide the inputs for each of following factors for each of the tractors it wished to certify under CO2 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-3.

The input values for the simulation model would be derived by the manufacturer from test procedures proposed by the agencies in this proposal. The agencies are proposing several testing alternatives for aerodynamic assessment, a single procedure for tire rolling resistance coefficient determination, and a prescribed method to determine tractor weight reduction. The agencies are proposing 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 CO2 and fuel consumption metric should reflect what we wish to control (CO2 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 proposing standards for Class 7 and 8 combination tractors that would be expressed in terms of moving a ton (2000 pounds) of freight over one mile. Thus, NHTSA's proposed 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 proposed CO2 vehicle standards would be represented as grams of CO2 per ton-mile.

Similarly, 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 Start Printed Page 74181of 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 proposing, 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 CO2 emissions. In the case of Class 7 and 8 tractors and our proposed 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 tractor can go up. Based on this general approach, it can be estimated that for every 1,200 pounds in mass reduction total truck 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 truck. The agencies seek comment on the use of a per ton-mile metric and also whether other metrics such as per cube-mile should be considered instead.

(c) Truck Aerodynamic Assessment

The aerodynamic drag of a vehicle is determined by the vehicle's coefficient of drag (Cd), frontal area, air density and speed. The agencies are proposing to establish and use pre-defined values for the input parameters to GEM which represent the frontal area and air density, while the speed of the vehicle would be determined in GEM through the proposed drive cycles. The agencies are proposing that the manufacturer would determine a truck's Cd, a dimensionless measure of a vehicle's aerodynamics, for input into the model through a combination of vehicle testing and vehicle design characteristics. Quantifying truck aerodynamics as an input to the GEM presents technical challenges because of the proliferation of truck configurations, the lack of a clearly preferable standardized test method, and subtle variations in measured Cd values among various test procedures. Class 7 and 8 tractor aerodynamics are currently developed by manufacturers using a range of techniques, including vehicle coastdown testing, wind tunnel testing, computational fluid dynamics, and constant speed tests as further discussed below. Reflecting that each of these approaches has limitations and no one approach appears to be superior to others, the agencies are proposing to allow all three aerodynamic evaluation methods to be used in demonstrating a vehicle's aerodynamic performance. The agencies welcome comments on each of these methods.

The agencies are proposing that the coefficient of drag assessment be a product of test data and vehicle characteristics using good engineering judgment. The primary tool the agencies expect to use in our own evaluation of aerodynamic performance is the coastdown procedure described in SAE Recommended Practice J2263. 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)). The agencies anticipate that as we and the industry gain experience with assessing aerodynamic performance of HD vehicles for purposes of compliance a test-only approach may have advantages.

We believe this broad approach allowing manufacturers to use multiple different test procedures to demonstrate aerodynamic performance is appropriate given that no single test procedure is superior in all aspects to other approaches. However, we also recognize the need for consistency and a level playing field in evaluating aerodynamic performance. To accomplish this, the agencies propose to use a two-part approach that evaluates aerodynamic performance not only through testing but through the application of good engineering judgment and a technical description of the vehicles aerodynamic characteristics. The first part of the proposed evaluation approach uses a bin structure characterizing the expected aerodynamic performance of tractors based on definable vehicle attributes. This bin approach is described further below. The second proposed evaluation element uses aerodynamic testing to measure the vehicle's aerodynamic performance under standardized conditions. The agencies expect that the SAE J2263 coastdown procedures will be the primary aerodynamic testing tool but are interested in working with the regulated industry and other interested stakeholders to develop a primary test approach. Additionally, the agencies propose to have a process that would allow manufacturers to demonstrate that another aerodynamic test procedure should also be allowed for purposes of generating inputs used in assessing a truck's performance. We are requesting comment on methods that should form the primary aerodynamic testing tool, methods that may be appropriate as alternatives, and the mechanism (including standards, practices, and unique criteria) for the agencies to consider allowing alternative aerodynamic test methods.

NHTSA and EPA are proposing that manufacturers use a two part screening approach for determining the aerodynamic inputs to the GEM. The first part would require the manufacturers to assign each vehicle aerodynamic configuration to one of five aerodynamics bins created by EPA and NHTSA as described below. The assignment by bin reflects the aerodynamic characteristics of the vehicle. For each bin, EPA and NHTSA have already defined a nominal Cd that will be used in the GEM and a range of Cd values that would be expected from testing of vehicles meeting this bin description. The second part would require the manufacturer to then compare its own test results of aerodynamic performance (as conducted in accordance with the agencies' requirements) for the vehicle to confirm the actual aerodynamic performance was consistent with the agencies' expectations for vehicles within this Start Printed Page 74182bin. If the predicted performance and actual observed performance match, the Cd value as an input for the GEM is the nominal Cd value defined for the bin. If, however, a manufacturer's test data demonstrates performance that is better than projected for the assigned bin a manufacturer may use the test data and good engineering judgment to demonstrate to the agencies that this particular vehicle's performance is in keeping with the performance level of a more aerodynamic bin and with the agencies' permission may use the Cd value of the more aerodynamic bin. Conversely, if the test data demonstrates that the performance is worse than the projected bin, then the manufacturer would use the Cd value from the less aerodynamic bin. Using this approach, the bin structure can be seen as the agencies' first effort to create a common measure of aerodynamic performance to benchmark the various test methods manufacturers may use to demonstrate aerodynamic performance. For example, if a manufacturer's test methods consistently produce Cd values that are better than projected by the agencies, EPA and NHTSA can use this information to further scrutinize the manufacturer's test procedure, helping to ensure that all manufacturers are competing on a level playing field.

The agencies are proposing aerodynamic technology bins which divide the wide spectrum of tractor aerodynamics into five bins (i.e., categories). The first category, “Classic,” represents tractor bodies which prioritize appearance or special duty capabilities over aerodynamics. The Classic 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 category for aerodynamics is the “Conventional” tractor body. The agencies consider Conventional tractors to be the average new tractor today which capitalizes on a generally aerodynamic shape and avoids classic features which increase drag. Tractors within the “SmartWay” category build on Conventional tractors with added components to reduce drag in the most significant areas on the tractor, such as fully enclosed roof fairings, side extending gap reducers, fuel tank fairings, and streamlined grill/hood/mirrors/bumpers. The “Advanced SmartWay” aerodynamic category builds upon the SmartWay tractor body with additional aerodynamic treatments such as underbody airflow treatment, down exhaust, and lowered ride height, among other technologies. And finally, “Advanced SmartWay II” 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 recognize that these proposed aerodynamic bins are static and referential and that there may be other technologies that may provide similar aerodynamic benefit. In addition, it is expected that aerodynamic equipment will advance over time and the agencies may find it appropriate and necessary to revise the bin descriptions.

Under this proposal, the manufacturer would then input into GEM the Cd value specified for each bin as also defined in Table II-4. For example, if a manufacturer tests a Class 8 sleeper cab high roof tractor with features which are similar to a SmartWay tractor and the test produces a Cd value of 0.59, then the manufacturer would assign this tractor to the Class 8 Sleeper Cab High Roof SmartWay bin. The manufacturer would then use the Cd value of 0.60 as the input to GEM.

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Coefficient of drag and frontal area of the tractor-trailer combination go hand-in-hand to determine the force required to overcome aerodynamic drag. As explained above, the agencies are proposing that the Cd value is one of the GEM inputs which will be derived by the manufacturer. However, the agencies are proposing to specify the truck's frontal area for each regulatory category (i.e., each of the seven subcategories which are proposed and listed in Table II-4 under the Aerodynamic Input to GEM). The frontal area of a high roof tractor pulling a box trailer will be determined primarily by the box trailer's dimensions and the ground clearance of the tractor. The frontal area of low and mid roof tractors will be determined by the tractor itself. An alternate approach to the proposed frontal area specification is to create the aerodynamic input table (as shown in Table II-4) with values that represent the Cd multiplied by the frontal area. This approach will provide the same aerodynamic load, but it will not allow the comparison of aerodynamic efficiency across regulatory categories that can be done with the Cd values alone. The agencies are interested in comments regarding the frontal area of trucks, specifically whether the specified frontal areas are appropriate and whether the use of standard frontal areas may have unanticipated consequences.

EPA and NHTSA recognize that wind conditions, most notably wind direction, have a greater impact on real world CO2 emissions and fuel consumption of heavy-duty trucks than of light-duty vehicles. As noted in the NAS report,[44] the wind average drag coefficient is about 15 percent higher than the zero degree coefficient of drag. The agencies considered proposing the use of a wind averaged drag coefficient in this regulatory program, but ultimately decided to propose using coefficient of 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 wind tunnels are currently the only tool to accurately assess the influence of wind speed and direction on a truck'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 technology effectiveness or change the kinds of technology decisions made by the tractor manufacturers in developing equipment to meet our proposed standards. However, the agencies are interested in receiving comment on approaches to develop wind averaged coefficient of drag values using computational fluid dynamics, coastdown, and constant speed test procedures.

The methodologies the agencies are considering for aerodynamic assessment include coastdown testing, wind tunnel testing, computational fluid dynamics, and constant speed testing. The agencies welcome information on a constant speed test procedure and how it could be applied to determine aerodynamic drag. In addition, the agencies seek comment on allowing multiple aerodynamic assessment methodologies and the need for comparison of aerodynamic assessment methods to determine method precision and accuracy.

(i) Coastdown Testing

The coastdown test procedure has been used extensively in the light-duty industry to capture the road load force by coasting a vehicle along a flat straightaway under a set of prescribed conditions. Coast down testing has been used less extensively to obtain road load forces for medium- and heavy-duty vehicles. EPA has conducted a significant amount of test work to demonstrate that coastdown testing per SAE J2263 produces reasonably repeatable test results for Class 7 and 8 tractor/trailer pairings, as described in draft RIA Chapter 3. The agencies propose that a manufacturer which chooses this method would determine a tractor's Cd value through analysis of the road load force equation derived from SAE J2263 Revised 2008-12 test results, as proposed in 40 CFR 1066.210.

(ii) Wind Tunnel Testing

A wind tunnel provides a stable environment yielding a more repeatable test than coastdown. This allows the manufacturer to run multiple baseline vehicle tests and explore configuration modifications for nearly the same effort (e.g., time and cost) as conducting the coastdown procedure. In addition, wind tunnels provide testers with the ability to yaw the vehicle at positive and negative angles relative to the original centerline of the vehicle to accurately capture the influence of non-uniform wind direction on the Cd (e.g., wind averaged Cd).

The agencies propose to allow the use of existing wind tunnel procedures adopted by SAE International with some minor modifications as discussed in Section V of this proposal. The agencies seek comments on the appropriateness of using the existing SAE wind tunnel procedures, and the modifications to these procedures, for this regulatory purpose.

(iii) Computational Fluid Dynamics

Computational fluid dynamics, or CFD, capitalizes on today's computing power by modeling a full size vehicle and simulating the flows around this model to examine the fluid dynamic properties, in a virtual environment. CFD tools are used to solve either the Navier-Stokes equations that relate the physical law of conservation of momentum to the flow relationship around a body in motion or a static body with fluid in motion around it, or the Boltzman equation that examines fluid mechanics and determines the characteristics of discreet, individual particles within a fluid and relates this behavior to the overall dynamics and behavior of the fluid. CFD analysis involves several steps: Defining the model structure or geometry based on provided specifications to define the basic model shape; applying a closed surface around the structure to define the external model shape (wrapping or surface meshing); dividing the control volume, including the model and the surrounding environment, up into smaller, discreet shapes (gridding); defining the flow conditions in and out of the control volume and the flow relationships within the grid (including eddies and turbulence); and solving the flow equations based on the prescribed flow conditions and relationships.

This approach can be beneficial to manufacturers since they can rapidly prototype (e.g., design, research, and model) an entire vehicle without investing in material costs; they can modify and investigate changes easily; and the data files can be re-used and shared within the company or with corporate partners.

The accuracy of the outputs from CFD analysis is highly dependent on the inputs. The CFD modeler decides what method to use for wrapping, how fine the mesh cell and grid size should be, and the physical and flow relationships within the environment. A balance must be achieved between the number of cells, which defines how fine the mesh is, and the computational times for a result (i.e., solution-time-efficiency). All of these decisions affect the results of the CFD aerodynamic assessment.Start Printed Page 74184

Because CFD modeling is dependent on the quality of the data input and the design of the model, the agencies propose and seek comment on a minimum set of criteria applicable to using CFD for aerodynamic assessment in Section V.

(d) Tire Rolling Resistance Assessment

NHTSA and EPA are proposing 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.[45] The agencies believe the ISO test procedure is appropriate to propose for this program because the procedure is the same one used by NHTSA in its fuel efficiency tire labeling program [46] and is consistent with the 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 vehicle. The results would be expressed as a rolling resistance coefficient and measured as kilogram per metric ton (kg/metric ton). The agencies are proposing 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 would use a combined tire rolling resistance, where 15 percent of the gross weight of the truck and trailer would be distributed to the steer axle, 42.5 percent to the drive axles, and 42.5 percent to the trailer axles.[47] The trailer tires' rolling resistance would be 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.[48]

We acknowledge that the useful life of original equipment tires used on tractors is shorter than the tractor's useful life. In this proposal, we are treating the tires as if the owner replaces the tire with tires that match the original equipment. Some owners opt for the original tires under the assumption that this is the best product. However, tractor tires are often retreaded or replaced. Steer tires on a highway tractor might need replacement after 75,000 to 150,000 miles. Drive tires might need retreading or replacement after 150,000 to 300,000 miles. Of course, tire removal miles can be much higher or lower, depending upon a number of factors that affect tire removal miles. These include the original tread depth; desired tread depth at removal to maintain casing integrity; tire material and construction; typical load; tire “scrub” due to urban driving and set back axles; and, tire under-inflation. Since it is common for both medium- and heavy-duty truck tires to be replaced and retreaded, we welcome comments in this area. We are specifically seeking data for the rolling resistance of retread and replacement heavy-duty tires and the typical useful life of tractor tires.

(e) Weight Reduction Assessment

EPA and NHTSA are seeking to account for the emissions and fuel consumption benefits of weight reduction as a control technology in heavy-duty trucks. Weight reduction impacts the emissions and fuel consumption performance of tractors in different ways depending on the truck's operation. For trucks that cube-out, the weight reduction will show a small reduction in grams of CO2 emitted or fuel consumed per mile travelled. The benefit is small because the weight reduction is minor compared to the overall weight of the combination tractor and payload. However, a weight reduction in tractors which operate at maximum gross vehicle weight rating would result in an increase in payload capacity. Increased vehicle payload without increased GVWR significantly reduces fuel consumption and CO2 emissions per ton mile of freight delivered. It also leads to fewer vehicle miles driven with a proportional reduction in traffic accidents.

The empty curb weight of tractors varies significantly today. Items as common as fuel tanks can vary between 50 and 300 gallons each for a given truck model. Information provided by truck manufacturers indicates that there may be as much as a 5,000 to 17,000 pound difference in curb weight between the lightest and heaviest tractors within a regulatory subcategory (such as Class 8 sleeper cab with a high roof). Because there is such a large variation in the baseline weight among trucks that perform roughly similar functions with roughly similar configurations, there is not an effective way to quantify the exact CO2 and fuel consumption benefit of mass reduction using GEM because of the difficulty in establishing a baseline. However, if the weight reduction is limited to tires and wheels, then both the baseline and weight differentials for these are readily quantifiable and well-understood. Therefore, the agencies are proposing that the mass reduction that would be simulated be limited only to reductions in wheel and tire weight. In the context of this heavy-duty vehicle program with only changes to tires and wheels, the agencies do not foresee any related impact on safety.[49] The agencies welcome comments regarding this approach and detailed data to further improve the robustness of the agencies' assumed baseline truck tare/curb weights for each regulatory category used within the model, as outlined in draft RIA Chapter 3.5.

EPA and NHTSA are proposing to specify the baseline vehicle weight for each regulatory category (including the tires and wheels), but allow manufacturers to quantify weight reductions based on the wheel material selection and single wide versus dual tires per Table II-5. The agencies assume the baseline wheel and tire configuration contains dual tires with steel wheels because these represent the vast majority of new vehicle configurations today. The proposed weight reduction due to the wheels and tires would be reflected in the payload tons by increasing the specified payload by the weight reduction amount discounted by two thirds to recognize that approximately one third of the truck miles are travelled at maximum payload, as discussed below in the payload discussion.

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(f) Extended Idle Reduction Technology Assessment

Extended idling from Class 8 heavy-duty long haul combination tractors contributes to significant CO2 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.[50] 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 truck cab itself than to pull off the road and find accommodations. During this rest period a driver will idle the truck in order to provide heating or cooling or run on-board appliances. In some cases the engine can idle in excess of 10 hours. During this period, the truck will consume approximately 0.8 gallons of fuel and emit over 8,000 grams of CO2 per hour. An average truck can consume 8 gallons of fuel and emit over 80,000 grams of CO2 during overnight idling in such a case.

Idling reduction technologies are available to allow for driver comfort while reducing fuel consumptions and CO2 emissions. Auxiliary power units, fuel operated heaters, battery supplied air conditioning, and thermal storage systems are among the technologies available today. The agencies are proposing to include extended idle reduction technology as an input to the GEM for Class 8 sleeper cabs. The manufacturer would input the value based on the idle reduction technology installed on the truck. As discussed further in Section III, if a manufacturer chooses to use idle reduction technology to meet the standard, then it would require an automatic main engine shutoff after 5 minutes to help ensure the idle reductions are realized in-use. 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 proposed standards. The proposed value (5 g CO2/ton-mile or 0.5 gal/1,000 ton-mile) for the idle reduction technologies was determined using an assumption of 1,800 idling hours per year, 125,000 miles travelled, and a baseline idle fuel consumption of 0.8 gallons per hour. Additional detail on the emission and fuel consumption reduction values are included in draft RIA Chapter 2.

(g) Vehicle Speed Limiters

Fuel consumption and CO2 emissions increase proportional to the square of vehicle speed.[51] 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. The feature is electronically programmed and controlled. Manufacturers today sell trucks with vehicle speed limiters and allow the customers to set the limit. However, as proposed the GEM will not provide a fuel consumption reduction for a limiter that can be overridden. In order to obtain a benefit for the program, the 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. As with other engine calibration aspects of emission controls, tampering with a calibration would be considered unlawful by EPA. If the manufacturer installs a vehicle speed limiter into a truck that is not easily overridden, then the manufacturer would input the vehicle speed limit setpoint into GEM.

(h) Defined Vehicle Configurations in the GEM

As discussed above, the agencies are proposing methodologies that manufacturers would use to quantify the values to be input into the GEM for these factors affecting truck efficiency: Coefficient of Drag, Tire Rolling Resistance Coefficient, Weight Reduction, Vehicle Speed Limiter, and Extended Idle Reduction Technology. The other aspects of vehicle performance are fixed within the model and are not varied for the purpose of compliance. The defined inputs being proposed include the drive cycle, tractor-trailer combination curb weight, payload, engine characteristics, and drivetrain for each vehicle type, and others. We are seeking comments accompanied with data on the defined model inputs as described in draft RIA Chapter 4.

(i) Vehicle Drive Cycles

As noted by the 2010 NAS Report,[52] 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. If the agencies propose an ill-suited drive cycle for a regulatory category, it may 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 Start Printed Page 74186delivery may spend little time on the highway, reducing the benefits that would be 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 CO2 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.[53] 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 truck has a different drive cycle in-use.

The agencies are proposing a modified version of the California ARB Heavy Heavy-duty Truck 5 Mode Cycle,[54] 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.[55] 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 truck application usage patterns. EPA analyzed the five cycles and found that some modifications to the modes appear to be needed to allow sufficient flexibility in weightings. The agencies are proposing the use of the Transient mode, as defined by California ARB, because it broadly covers urban driving. The agencies are also proposing altered versions of the High Speed Cruise and Low Speed Cruise modes which would reflect only constant speed cycles at 65 mph and 55 mph respectively. EPA and NHTSA relied on the EPA MOVES analysis of Federal Highway Administration data to develop the proposed mode weightings to characterize typical operations of heavy-duty trucks, per Table II-6 below.[56] A detailed discussion of drive cycles is included in draft RIA Chapter 3.[57]

(ii) 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 truck is important because it in part determines the impact of technologies, such as rolling resistance, on GHG emissions and fuel consumption. The agencies are proposing to specify each of these aspects of the vehicle.

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.[58] Details of the individual weight inputs by regulatory category are included in draft RIA Chapter 3.

There are several methods that the agencies have considered for evaluating the GHG emissions and fuel consumption of tractors used to carry freight. A key factor in these methods is the weight of the truck that is assumed for purposes of the evaluation. 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).[59]

As described above, the amount of payload that a tractor can carry depends on the category (or GVWR) of the vehicle. For example, a typical Class 7 tractor can carry less payload than a Class 8 tractor. The Federal Highway Administration developed Truck Payload Equivalent Factors to inform the development of highway system strategies using Vehicle Inventory and Use Survey (VIUS) and Vehicle Travel Information System data. Their results Start Printed Page 74187found that the average payload of a Class 8 truck ranged from 36,247 to 40,089 pounds, depending on the average distance travelled per day.[60] The same results found that Class 7 trucks carried between 18,674 and 34,210 pounds of payload also depending on average distance travelled per day. Based on this data, the agencies are proposing 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 are proposing a common payload for Class 8 day cabs and sleeper cabs because the data available does 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.” Additional details on proposed payloads are included in draft RIA Chapter 3.

(iii) Standardized Trailers

NHTSA and EPA are proposing that the tractor performance in the GEM would be judged by assuming it is pulling a standardized trailer. The agencies believe that an assessment of the tractor aerodynamics should be conducted using a tractor-trailer combination to reflect the impact of aerodynamic technologies in actual use, where tractors are designed and used with a trailer. Assessing the tractor aerodynamics using only the tractor would not be a reasonable way to assess in-use impacts. For example, the in-use aerodynamic drag while pulling a trailer is different than without the trailer and the full impact of an aerodynamic technology on reducing emissions and fuel consumption would not be reflected if the assessment is performed on a tractor without a trailer.

In addition to assessing the tractor with a trailer, it is appropriate to adopt a standardized trailer used for testing, and to vary the standardized trailer by the regulatory category. This is similar to the standardization of payload discussed above, as a way to reasonably reflect in-use operating conditions. High roof tractors are optimally designed to pull box trailers. The roof fairing on a tractor is the feature designed to minimize the height differential between the tractor and typical trailer to reduce the air flow disruption. Low roof tractors are designed to carry flat bed or low-boy trailers. Mid roof tractors are designed to carry tanker and bulk carrier trailers. The agencies conducted a survey of tractor-trailer pairing in-use to evaluate the representativeness of this premise. The survey of over 3,000 tractor-trailer combinations found that in 95 percent of the combination tractors the tractor's roof height was paired appropriately for the type of trailer that it was pulling.[61] The agencies also have evaluated the impact of pairing a low roof tractor with a box trailer in coastdown testing and found that the aerodynamic force increases by 20 percent over a high roof tractor pulling the same box trailer.[62] Therefore, drivers have a large incentive to use the appropriate matching to reduce their fuel costs. However, the agencies recognize that in operation tractors sometimes pull trailers other than the type that it was designed to carry. The agencies are proposing the matching of trailers to roof height for the test procedure. To do otherwise would necessarily result in a standard reflecting substandard aerodynamic performance, and thereby result in standards which are less stringent than would be appropriate based on the reasonable assumption that tractors will generally pair with trailer of appropriate roof height. The other aspects of the test procedure such as empty trailer weight, location of payload, and tractor-trailer gap are being proposed for each regulatory category to provide consistent test procedures.

(iv) Standardized Drivetrain

The agencies' assessment of the current vehicle configuration process at the truck dealer's level is 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 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 proposing 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 GEM

As the agencies are proposing separate engine and tractor standards, the GEM will be used to assess the compliance of the tractor with the tractor standard. To maintain the separate assessments, the agencies are proposing to define 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 tractor that uses an engine with emissions and fuel consumption better than the standards would require fewer vehicle reductions than those technically feasible reductions being proposed. The agencies are proposing two distinct fuel consumption maps for use in GEM. EPA proposes the first fuel consumption map would be used in GEM for the 2014 through 2016 model years and represents an average engine which meets the 2014 model year engine CO2 emissions standards being proposed. NHTSA proposes to use the same fuel map for its 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 would be used beginning in 2017 model year and represents an engine which meets the 2017 model year CO2 emissions and fuel consumption standards and accounts for the increased stringency in the proposed MY 2017 standard. Effectively there is no change in stringency of the tractor vehicle (not including the engine) and there is stability in the tractor vehicle (not including engine) standards for the full rulemaking period.[63] These inputs are appropriate given the separate proposed regulatory requirement that Class 7 and 8 combination tractor manufacturers use only certified engines.

(i) Engine Test Procedure

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.[64] An analogous metric for engines would be the amount of fuel consumed per unit of work. Thus, EPA is proposing that GHG emission standards for engines under the CAA would be expressed as g/bhp-Start Printed Page 74188hr; NHTSA's proposed fuel consumption standards under EISA, in turn, would be represented as gal/100 bhp-hr. This metric is also consistent with EPA's current standards for non-GHG emissions for these engines.

EPA's criteria pollutant standards for engines require that manufacturers demonstrate compliance over the transient Heavy-duty FTP test cycle; the steady-state SET test cycle; and the not-to-exceed test (NTE test). 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. With regard to GHG and fuel consumption control, the agencies believe it is more 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. For engines used primarily in line-haul combination tractor trailer operations, we believe the steady-state SET procedure more appropriately reflects in-use engine operation. By setting standards based on the most representative test cycle, we can have confidence that engine manufacturers will design engines for the best GHG and fuel consumption performance relative to the most common type of expected engine operation. There is no incentive to design the engines to give worse fuel consumption under other types of operation, relative to the most common type of operation, and we are not concerned if manufacturers further calibrate these designs to give better in-use fuel consumption during other operation, while maintaining compliance with the criteria emissions standards as such calibration is entirely consistent with the goals of our joint program.

Further, we are concerned that setting standards based on both transient and steady-state operating conditions for all engines could lead to undesirable outcomes. For example, turbocompounding is one technology that the agencies have identified as a likely approach for compliance against our proposed HHD SET standard described below. 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 only for engines intended for use in combination tractor trailers could lead manufacturers to not apply turbocompounding because the full benefits are not demonstrated on the Heavy-duty FTP even though it can be a highly cost-effective means to reduce GHG emissions and lower fuel consumption in more steady state applications.

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 are proposing to exclude the CO2 emissions and fuel consumption increases due to regeneration from the calculation of the compliance levels over the defined test procedures. We considered including regeneration in the estimate of fuel consumption and GHG emissions and have 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 NOX 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 timeframe of this proposal. 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 CO2 emissions control and fuel consumption reductions than we will achieve by not including regeneration emissions. We are seeking comments regarding regeneration emissions and what approach if any the agencies should use in reflecting regeneration emissions in this program.

In conclusion, for Class 7 and 8 tractors, compliance with the vehicle standard would be determined by establishing values for the variable inputs and using the prescribed inputs in GEM and compliance against the engine standard using the SET engine cycle. The model would produce CO2 and fuel consumption results that would be compared against EPA's and NHTSA's respective standards.

(j) Chassis-Based Test Procedure

The agencies also 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.[65]

In addition, and of equal if not greater importance, because of the enormous numbers of truck 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 CO2 emissions of the Start Printed Page 74189tractor. 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 was adopted based on a chassis test procedure.

Although the agencies are not proposing the use of a complete chassis based test procedure for Class 7 and 8 tractors, we believe such an approach could 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. We request comments on the potential use of chassis based test procedures in the future to augment or replace the model based approach we are proposing.

(3) Summary of Proposed Flexibility and Credit Provisions

EPA and NHTSA are proposing 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.

The agencies are proposing that credits earned by manufacturers under this ABT program be restricted for use to only within the same regulatory subcategory for two reasons. First, relating credits between categories is tenuous because of the differences in regulatory useful lives. We want to avoid having credits from longer useful life categories flooding shorter useful life categories, adversely impacting compliance with CO2 or fuel consumption standards in the shorter useful life category, and we have not based the level of the standard on such impact on compliance. In addition, extending the use of credits beyond these designated categories could inadvertently have major impacts on the competitive market place, and we want to avoid such results. For example, a manufacturer which has multiple engine offerings over several regulatory categories could mix credits across engine categories and shift the burden between them, possibly impacting the competitive market place. Similarly, integrated manufacturers which produce both engines and trucks could shift credits between engines and trucks and have a similar effect. We would like to ensure that this proposal reduces the CO2 emissions and fuel consumption but does not inadvertently have such impacts on the market place. However, we welcome comments on the extension of credits beyond the limitations we are proposing.

The agencies are also proposing to provide provisions to manufacturers for early credits, the use of advanced technologies and innovative technologies which are described in greater detail in Section IV.

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

EPA and NHTSA are proposing to defer 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.[66] 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 or engine manufacturers.

The agencies have identified two entities that fit the SBA size criterion of a small business.[67] 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,[68] and therefore that the exemption will have a negligible impact on the GHG emissions and fuel consumption improvements from the proposed standards.

To ensure that the agencies are aware of which companies would be exempt, we propose 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.

C. Heavy-Duty Pickup Trucks and Vans

The primary elements of the EPA and NHTSA programs being proposed for complete HD pickups and vans are presented in this section. These provisions also cover incomplete HD pickups and vans that are sold by vehicle manufacturers as cab-chassis (chassis-cab, box-delete, bed-delete, cut-away van) vehicles, as discussed in detail in Section V.B(1)(e). Section II.C(1) explains the proposed form of the CO2 and fuel consumption standards, the proposed numerical levels for those standards, and the proposed approach to phasing in the standards over time. The proposed measurement procedure for determining compliance is discussed in Section II.C(2), and the proposed EPA and NHTSA compliance programs are discussed in Section II.C(3). Sections II.C(4) discusses proposed implementation flexibility provisions. Section II.E discusses additional standards and provisions for N2 O and CH4 emissions, for impacts from vehicle air conditioning, and for ethanol-fueled and electric vehicles.

(1) What Are the Proposed 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 vehicle 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.[69] 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 Start Printed Page 74190brakes), 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 proposed 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.”

(b) Weight-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 proposal, 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. Weight-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 weight-based differences in design and in-use operation are the key factors in evaluating technological improvements for reducing CO2 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.[70]

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 combined 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 weight-based attributes would avoid 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 have decided to propose standards for HD pickups and vans based on a “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 would account for the fact that 4wd, critical to enabling the many off-road heavy-duty work applications, adds roughly 500 lb to the vehicle weight. Under our proposal, target GHG and fuel consumption standards would be determined for each vehicle with a unique work factor. These targets would then be production weighted and summed to derive a manufacturer's annual fleet average standards.

To ensure consistency and help preclude gaming, we are proposing that payload capacity be defined as GVWR minus curb weight, and towing capacity as GCWR minus GVWR. We are proposing that, for purposes of determining the work factor, GCWR be defined according to SAE Recommended Practice J2807 APR2008, GVWR be defined consistent with EPA's criteria pollutants program, and curb weight be defined as in 40 CFR Start Printed Page 7419186.1803-01. We request comment on the need to establish additional regulations or guidance to ensure that these terms are determined and applied consistently across the HD pickup and van industry for the purpose of determining standards.

Based on analysis of how CO2 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.[71] We request comment on this proposed approach.

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 proposed 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 CO2 is emitted in moving heavier loads than in moving lighter loads. Both of these load-based approaches avoid penalizing truck 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 proposal 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.

These attribute-based CO2 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 CO2 emissions and fuel consumption, and therefore all HD pickups and vans would be affected by the standard. With the proposed 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) Proposed Standards

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

  • The level of technology that is incorporated in current new HD pickups and vans,
  • The available data on corresponding CO2 emissions and fuel consumption for these vehicles,
  • Technologies that would reduce CO2 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 proposing the CO2 attribute-based target standards shown in Figure II-1 and II-2, and NHTSA is proposing the equivalent attribute-based fuel consumption target standards, also shown in Figure II-1 and II-2, 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 statutory obligations. Also, for reasons discussed below, separate targets are being established for gasoline-fueled (and any other Otto-cycle) vehicles and diesel-fueled (and any other Diesel-cycle) vehicles. The targets would be used to determine the production-weighted standards that apply to the combined diesel and gasoline fleet of HD pickups and vans produced by a manufacturer in each model year.

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Described [73] mathematically, EPA's and NHTSA's proposed functions are defined by the following formulae:

EPA CO2 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-7 or Table II-8.[74]

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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. Much of the information used to make this technology assessment was developed for the recent 2012-2016 MY light-duty vehicle rule. 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 proposing 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 CO2 and fuel consumption for diesel and gasoline vehicles, respectively, relative to a common baseline for current (model year 2010) vehicles. An additional two percent reduction in GHGs would be achieved by the EPA program from a proposed direct air conditioning leakage standard. 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 Start Printed Page 74195levels for gasoline and diesel vehicles, which is important in ensuring our proposed program maintains product choices available to vehicle buyers.

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 CO2 using conversion factors of 8,887 g CO2/gallon for gasoline and 10,180 g CO2/gallon for diesel fuel.

It is expected that measured performance values for CO2 would generally be equivalent to fuel consumption. However, as explained below in Section II. E. (3), EPA is proposing an alternative for manufacturers to demonstrate compliance with N2 O and CH4 emissions standards through the calculation of a CO2-equivalent (CO2 eq) emissions level that would be compared to the CO2-based standards, similar to the recently promulgated light-duty GHG standards for model years 2012-2016. For test families that do not use this compliance alternative, the measured performance values for CO2 and fuel consumption would be equivalent because the same test runs and measurement data would be used to determine both values, and calculated fuel consumption would be based on the same conversion factors that are used to establish the relationship between the CO2 and fuel consumption target curves (8887 g CO2/gallon for gasoline and 10,180 g CO2/gallon for diesel fuel). In this case, for example, if a manufacturer's fleet average measured compliance value exactly meets the fleet average CO2 standard, it will also exactly meet the fuel consumption standard. The proposed NHTSA fuel consumption program will not use a CO2 eq metric. Measured performance to standards would be based on the measurement of CO2 with no adjustment for N2 O and CH4. For manufacturers that choose to use the EPA CO2 eq approach, compliance with the CO2 standard would not be directly equivalent to compliance with the NHTSA fuel consumption standard.

(d) Proposed Implementation Plan

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

EPA is proposing 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 would need to meet a fleet-average standard that would become increasingly more stringent each year of the phase-in period. For both gasoline and diesel vehicles, this phase-in would be 15-20-40-60-100 percent 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 CO2 from a common unregulated baseline. For example, in 2014 the reduction for both diesel and gasoline vehicles would be 15% of the fully-phased-in reductions. Figures II-1 and II-2, and Table II-7, reflect this phase-in approach.

EPA is also proposing to provide manufacturers with an optional alternative implementation schedule in model years 2016 through 2018, equivalent to NHTSA's proposed first alternative for standards that do not change over these model years, described below. Under this option the phase-in would be 15-20-67-67-67-100 percent in model years 2014-2015-2016-2017-2018-2019, respectively. Table II-8, above, provides the coefficients “a” and “b” for this manufacturer's alternative. 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 would 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 in 2014. EPA also requests comment on a different regulatory approach to the phase-in, intended to reduce the testing and certification burden on manufacturers during the 2014-2017 phase-in years, while achieving GHG reductions on the same schedule as the proposed phase-in. In this alternative approach, each manufacturer would be required to demonstrate compliance with the final 2018 targets, but only over a predefined percentage of its HD pickup and van production. The remaining vehicles produced each year would not be regulated for GHGs. Thus this approach would have the effect of setting final standards in 2014 that do not vary over time, but with an annually increasing set of regulated vehicles. The percentage of regulated vehicles would increase each year, to 100 percent in 2018. We think it likely that manufacturers would leave the highest emitting vehicles unregulated for as long as possible under this approach, because these vehicles would tend to be the costliest to redesign or may simply be phased out of production. We therefore expect that, to be equivalent, the percentage penetration each year would be higher than the 15-20-40-60 percent penetrations required under the proposed approach. EPA requests comment on this regulatory alternative, and on what percentage penetrations are appropriate to achieve equivalent program benefits.

(ii) NHTSA Program Phase-In 2016 and Later

NHTSA is proposing to allow manufacturers to select one of two fuel consumption standard alternatives for model years 2016 and later. Manufacturers would select an alternative at the same time they submit the model year 2016 Pre-Certification Compliance Report; and, once selected, the alternative would apply for model years 2016 and later, and could not be reversed. To meet the EISA statutory requirement for three years of regulatory stability, the first alternative would define a fuel consumption target line function for gasoline vehicles and a target line function for diesel vehicles that would not change for model years 2016 and later. The proposed target line function coefficients are provided in Table II-8.

The second alternative would be equivalent to the EPA target line functions in each model year starting in 2016 and continuing afterwards. Stringency of fuel consumption standards would increase gradually for the 2016 and later model years. Relative to a model year 2010 unregulated baseline, for both gasoline and diesel vehicles, stringency would 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 2018 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 Start Printed Page 74196either alternative and have a similar credit balance at the end of model year 2018 under the EPA and NHTSA programs.

NHTSA also requests comment on a different regulatory approach that would parallel the above-described EPA regulatory alternative involving certification of a pre-defined percentage of a manufacturer's HD pickup and van production.

(iii) NHTSA Voluntary Standards Period

NHTSA is proposing 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 into the program, the program would become mandatory and the manufacturer would not be allowed to reverse this decision. To opt into the program, a manufacturer must declare its intent to opt in to the program at the same time it submits the Pre-Certification Compliance Report. See proposed regulatory text for 49 CFR 535.8 for information related to the Pre-Certification Compliance Report. If a manufacturer elects to opt into the program in 2014, the program would be mandatory for 2014 and 2015. 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 2018 target line function (under the NHTSA second alternative) in model years 2014-2015, respectively. The corresponding absolute standards targets levels are provided in Figure II-1 and II-2, and the accompanying equations.

NHTSA also requests comment on a different regulatory approach that would parallel the above-described EPA regulatory alternative involving certification of a pre-defined percentage of a manufacturer's HD pickup and van production.

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

EPA and NHTSA are proposing 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 would be identical to that of the light-duty test, other test parameters for running the HFET, such as test vehicle loaded weight, would be 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 would 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 proposed work factor-based CO2 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 CO2 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. 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 1/2 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 1/2 payload better fits their usage in the real world and would 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. We are therefore proposing to use ALVW for test vehicle loading in GHG and fuel consumption testing.

EPA and NHTSA request comment on the proposed test cycles, weighting factors, test loading conditions, and other factors that are important for establishing an effective GHG and fuel consumption test program. Additional provisions for our proposed testing and compliance program are provided in Section V.B.

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

EPA and NHTSA are proposing fleet average standards for new HD pickups and vans, based on a manufacturer's new vehicle fleet makeup. In addition, EPA is proposing in-use standards that would apply to the individual vehicles in this fleet over their useful lives. The compliance provisions for these proposed 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 below and in greater detail in Section V.B. We request comment on any compliance provisions we have taken from the light-duty program that commenters feel would not be appropriate for HD pickups and vans or that should be adjusted in some way to better regulate HD GHGs and fuel consumption cost-effectively.

(a) Fleet Average Standards

In this proposal we outline how each manufacturer would 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 would have individual targets at numerically higher CO2 and fuel consumption levels than lower payload/towing vehicles would, as discussed in Section II.C(1). The fleet average standard for a manufacturer would be 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 would be based on its final production figures for the model year, and thus a final assessment of compliance would occur after production for the model year ended. Because compliance with the fleet average standards depends on Start Printed Page 74197actual 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 would 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 would issue a certificate for the vehicles covered by the test group based on this demonstration, and would 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 would 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 would 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 CO2 emissions and fuel consumption performance, and are therefore proposing 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 would be used. EPA and NHTSA anticipate that the deterioration factor would be updated from time to time, as new data regarding emissions deterioration for CO2 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 proposing would apply to individual vehicles. NHTSA is not proposing to adopt in-use standards because it is not required under EISA, and because it is not currently anticipated that there will be any notable deterioration of fuel consumption. For the EPA proposal, 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 proposing 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 proposing 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 proposing 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 proposing an 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 proposing that each model's in-use CO2 standard would 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).

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

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

This proposal 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 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 proposing that at the end of each model year, when production for the model year is complete, a manufacturer calculate its production-weighted fleet average CO2 and fuel consumption. Under this proposed approach, a manufacturer's HD pickup and van fleet that achieves a fleet average CO2 or fuel consumption level better than its standard would be allowed to generate credits. Conversely, if the fleet average CO2 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 would 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 2012-2016 MY light-duty vehicle National Program, 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 would 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 years, consistent with the light-duty program. We are proposing that, after satisfying any need to offset pre-existing deficits, a manufacturer may bank remaining credits for use in future years. We are also proposing 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 proposing any credit transferability to or from other credit programs, such as the light-duty GHG and fuel consumption programs or the proposed heavy-duty engine ABT program.

Consistent with the President's May 21, 2010 directive to promote advanced technology vehicles, we are proposing and seeking comment on flexibility provisions that would parallel similar provisions adopted in the light-duty program. These include credits for advance technology vehicles such as electric vehicles, and credits for Start Printed Page 74198innovative 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.

We believe that it may also be appropriate to take steps to recognize the benefits of flexible-fueled vehicles (FFVs) and dedicated alternative-fueled vehicles based on the approach taken by EPA in the light-duty vehicle rule for later models years (2016 and later). However, unlike in that rule, we do not believe it is appropriate to create a provision for additional credits similar to the 2012-2015 light-duty program because the HD sector does not have the incentives mandated in EISA for light-duty vehicles. In fact, since heavy-duty vehicles were not included in the EISA incentives for FFVs, manufacturers have not in the past produced FFV heavy-duty vehicles. On the other hand, we do seek 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.[75] As proposed, FFV performance would be determined in the same way as for light-duty vehicles, with a 50-50 weighting of alternative and conventional fuel test results through MY 2015, and a 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). For dedicated alternative fueled vehicles, NHTSA proposes that vehicles be tested with the alternative fuel, and a petroleum equivalent fuel consumption level be calculated based on the Petroleum Equivalency Factor (PEF) that is determined by the Department of Energy. However, we are accepting comment on whether to provide a flexibility program similar to the program we currently offer for light-duty FFV vehicles.

D. Class 2b-8 Vocational Vehicles

Class 2b-8 vocational vehicles consist of a very wide variety of configurations including delivery, refuse, utility, dump, cement, transit bus, shuttle bus, school bus, emergency vehicle, motor homes,[76] and tow trucks, among others. The agencies are defining that Class 2b-8 vocational vehicles are all heavy-duty vehicles which are not included in the Heavy-duty Pickup Truck and Van or the Class 7 and 8 Tractor categories, with the exception of vehicles for which the agencies are deferring setting of standards, such as small business manufacturers. In addition, recreational vehicles are included under EPA's proposed standards but are not included under NHTSA's proposed standards.

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 agencies face difficulties in establishing the baseline CO2 and fuel consumption performance for the wide variety of vocational vehicles which makes it difficult to try and set different standards for a large number of potential regulatory categories. 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. Furthermore, the agencies evaluated the aerodynamic improvement opportunities for vocational vehicles. For example, the aerodynamics of a fire truck are impacted significantly by the equipment such as ladders located on the exterior of the truck. 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 no fuel consumption reduction opportunity through aerodynamic technologies for bucket trucks, transit buses, and refuse trucks [77] 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 trucks which operate at higher speeds.[78] To overcome the lack of baseline information from the different vehicle applications without sacrificing much fuel consumption or GHG emission reduction potential, the agencies propose to set standards for the chassis manufacturers of vocational vehicles (instead of the body builders) and the engine manufacturers.

EPA is proposing CO2 standards and NHTSA is proposing fuel consumption standards for manufacturers of chassis for new vocational vehicles and for manufacturers of heavy-duty engines installed in these vehicles. The proposed heavy-duty engine standards for CO2 emissions and fuel consumption would focus on potential technological improvements in fuel combustion and overall engine efficiency and those proposed controls would achieve most of the emission reductions. Further reductions from the Class 2b-8 vocational vehicle itself are possible within the timeframe of these proposed regulations. Therefore, the agencies are also proposing 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 draft RIA Chapter 2, show that these proposed standards appear appropriate under each agency's respective statutory authorities. Together these standards are estimated to achieve reductions of up to 11 percent from vocational vehicles.

EPA is also proposing standards to control N2 O and CH4 emissions from Class 2b-8 vocational vehicles. The proposed heavy-duty engine standards for both N2 O and CH4 and details of the standard are included in the discussion in Section II. EPA is not proposing air conditioning leakage standards applying to chassis manufacturers to address HFC emissions.

As discussed further below, the agencies propose to set CO2 and fuel consumption standards for these 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 propose to aggregate several vehicle weight categories under a single category for setting the standards. The agencies propose to divide the vocational vehicle segment into three broad regulatory categories—Light Start Printed Page 74199Heavy-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 are interested in comment on this segmentation strategy (subcategorization). 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.

(1) What are the proposed CO2 and fuel consumption standards and their timing?

In developing the proposed 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 CO2 and fuel savings that may be achieved. The technologies that the agencies considered while setting the proposed vehicle-level standards include improvements in lower rolling resistance tires. The technologies that the agencies considered while setting the engine standards include engine friction reduction, aftertreatment optimization, among others. The agencies' evaluation indicates that these technologies are available today in the heavy-duty tractor and light-duty vehicle markets, but have very low application rates in the vocational market. The agencies have analyzed the technical feasibility of achieving the proposed CO2 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 proposed 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 proposed vocational vehicle standards in Section III.

(a) Proposed Chassis Standards

As shown in Table II-9, EPA is proposing the following CO2 standards for the 2014 model year for the Class 2b through Class 8 vocational vehicle chassis. Similarly, NHTSA is proposing 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 proposed standard applies throughout the useful life of the vehicle.

EPA and NHTSA are proposing more stringent vehicle standards for the 2017 model year which reflect the CO2 emissions reductions required through the 2017 model year engine standards. As explained in Section II. D. (2)(c)(iv) 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 manufacturers installing additional vehicle technologies.

(i) Off-Road Vocational Vehicle Standards

In developing  the proposal EPA and NHSTA received comment from manufacturers and owners that certain vocational vehicles sometimes have very limited on-road usage. These trucks are defined to be motor vehicles under 40 CFR 85.1703, but they will spend the majority of their operations off-road. Trucks, such as those used in oil fields, will experience little benefit from low rolling resistance tires. The agencies are therefore proposing to allow a narrow range of these de facto off-road trucks to be excluded from the proposed vocational vehicle standards because the trucks require special off-road tires such as lug tires. The trucks must still use a certified engine, which will provide fuel consumption and CO2 emission reductions to the truck in all Start Printed Page 74200applications. To insure that these trucks are in fact used chiefly off-road, the agencies are proposing requirements that the vehicles have off-road tires, have limited high speed operation, and are designed for specific off-road applications. The agencies are specifically proposing that a truck must meet the following requirements to qualify for an exemption from the vocational vehicle standards:

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

EPA and NHTSA have concluded that the on-road performance losses and additional costs to develop a truck which meets these specifications will limit the exemption to trucks built for the desired purposes. The agencies welcome comment on the proposed requirements and exemptions.

(b) Proposed Heavy-duty Engine Standards

EPA is proposing GHG standards [80] and NHTSA is proposing 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. The agencies' analyses, as discussed briefly below and in more detail later in this preamble and in the draft 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. In developing the proposed 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.

With respect to the lead time and cost of incorporating technology improvements that reduce GHG emissions and fuel consumption, the agencies place important weight on the fact that during MYs 2014-2017, engine manufacturers are expected to redesign and upgrade their products only once. 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 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 proposed GHG and fuel consumption reductions, and to do this as part of the normal engine redesign process. This is an important aspect of the proposed 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. 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.

EPA's existing criteria pollutant emissions regulations for heavy-duty highway engines establish four regulatory categories (three for compression-ignition or diesel engines and one for spark ignition or gasoline engines) that represent the engine's intended and primary truck application, as shown in Table II-10 (40 CFR 1036.140). The agencies welcome comments on the existing definition of the regulatory categories (such as typical horsepower levels) as described in 40 CFR 1036.140. All heavy-duty engines are covered either under the heavy-duty pickup truck and van category or under the heavy-duty engine standards.

For the purposes of the GHG engine emissions and engine fuel consumption standards that EPA and NHTSA are proposing, the agencies intend to maintain these same four regulatory subcategories for GHG engine emissions standards and fuel consumption standards. This category structure would enable the agencies to set standards that appropriately reflect the technology available for engines for use in each type of vehicle.

(i) Diesel Engine Standards

EPA's proposed heavy-duty diesel engine CO2 emission standards are presented in Table II-11. Similar to EPA's non-GHG standards approach, manufacturers may generate and use credits to show compliance with the standards. The EPA standards become effective in 2014 model year, with more stringent standards becoming effective in model year 2017. Recently, EPA's Start Printed Page 74201non-GHG heavy-duty engine program provided new emissions standards for the industry in three year increments. Largely, the heavy-duty engine and truck manufacturer product plans have fallen into three year cycles to reflect this environment. The proposed two-step CO2 emission standards recognize the opportunity for technology improvements over this timeframe while reflecting the typical diesel truck manufacturer product plan cycles.

NHTSA's fuel consumption standards, also presented in Table II-11, would contain voluntary engine standards starting in 2014 model year, with mandatory engine standards starting in 2017 model year, synchronizing with EPA's 2017 model year standards. A manufacturer may opt-in to NHTSA's voluntary standards in 2014, 2015 or 2016. Once a manufacturer opts-in, the standards become mandatory for the opt-in and subsequent model years, and the manufacturer may not reverse its decision. To opt into the program, a manufacture must declare its intent to opt in to the program with documented communication of the intent, at the same time it submits the Pre-Certification Compliance Report. See 49 CFR 535.8 for information related to the Pre-Certification Compliance Report. A manufacturer opting into the program would begin tracking credits and debits beginning in the model year in which they opt into the program.

The agencies are proposing the same standard level for the Light Heavy and Medium Heavy diesel engine categories. 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 CO2 emissions from data provided to EPA by the manufacturers during the non-GHG certification process. Analysis of CO2 emissions from 2010 model year LHD and MHDD diesel engines showed little difference between LHD and MHD diesel engine baseline CO2 performance, which overall averaged 630 g CO2/bhp-hr (6.19 gal/100 bhp-hr),[81] in the 2010 model year. Furthermore, the technologies available to reduce fuel consumption and CO2 emissions from these two categories of engines are similar. The agencies are proposing to maintain these two separate engine categories with the same standard level (instead of combining them into a single category) to respect the different useful life periods associated with each category. The agencies are proposing to evaluate compliance with the LHD/MHD diesel engine standards based on the Heavy-duty FTP cycle.

The agencies found a difference in the baseline 2010 model year CO2 and fuel consumption performance between the LHD/MHD diesel engines, which averaged 630 g CO2/bhp-hr (6.19 gal/100 bhp-hr),[82] and the HHD diesel engines, which averaged 584 g CO2/bhp-hr (5.74 gal/100 bhp-hr). The HHD diesel engine data is also based on manufacturer submitted CO2 data for non-GHG emissions certification process. In addition, the agencies believe that there may be some technologies available to reduce fuel consumption and CO2 emissions that may not be appropriate for both the LHD/MHD diesel and the HHD diesel engines, such as turbocompounding. Therefore, the agencies are proposing a standard level for HHD diesel engines which differs from the LHD/MHD diesel engine standard level likewise to be evaluated on the Heavy-duty FTP cycle.

We are proposing 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 some steady cruise conditions as represented on the Heavy-duty FTP. The primary reason the agencies are proposing to set two separate HHD diesel engine standards—one for HHD diesel engines used in tractors and the other for HHD 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. 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 line haul tractors would be required to meet the standard based on the SET, which is a steady state test cycle. On the other hand, vocational vehicles such as urban delivery trucks spend more time operating in transient conditions and may not realize the benefit of this type of technology in-use. The use of the Heavy-duty FTP for these engines would focus engine design on technologies that realize in-use benefits during the kind of operation typical for these engines. Therefore, we are proposing that engines installed in vocational vehicles be required to meet the standard and demonstrate compliance over the transient Heavy-duty FTP cycle. The levels of the standards reflect the difference in baseline emissions for the different test procedures.

As noted in Section II.B above, the engine standards that EPA is proposing and the voluntary standards being proposed by NHTSA for the 2014 model year would require diesel engine manufacturers to achieve on average a three percent reduction in fuel consumption and CO2 emissions over the baseline 2010 model year performance for the HHD diesel engines and a five percent reduction for the LHD and MHD diesel engines. The agencies' assessment of the NAS report and other literature sources indicates that there are technologies available to reduce fuel consumption by this level in the proposed timeframe in a cost-effective manner. These technologies include improved turbochargers, aftertreatment optimization, low temperature exhaust gas recirculation, and engine friction reductions. Additional discussion on technical feasibility is included in Section III below and in draft RIA Chapter 2.

Additionally, the agencies are proposing that diesel engines further reduce fuel consumption and CO2 emissions in the 2017 model year. The proposed 2017 model year standards for the LHD and MHD diesel engines represent a 9 percent reduction from the 2010 model year. The proposed reductions represent on average a five percent decrease over the 2010 baseline for HHD diesel engines required to test compliance using the Heavy-duty FTP test cycle. The additional reductions may be achieved through the increased development of the technologies evaluated for the 2014 model year standard. See draft RIA Chapter 2. The agencies' analysis indicates that this type of advanced engine development will require a longer development time than the 2014 model year and therefore are proposing to provide additional lead time to allow for its introduction.

Similar to EPA's non-GHG standards approach, manufacturers may generate and use credits by the same engine subcategory to show compliance with both agencies' standards.

Start Printed Page 74202

In proposing these standards for diesel engines used in vocational vehicles, the agencies have looked primarily at the typical performance levels of the majority of engines in the fleet. As explained above in Section II.B, we also recognize that when regulating a category of products for the first time, there will be individual products that may deviate from this baseline level of performance. Recognizing that for these products a reduction from the industry baseline may be more costly than the agencies have assumed or perhaps even not feasible in the lead time available for these standards, EPA and NHTSA are proposing a regulatory alternative whereby a manufacturer could comply with a unique standard based on a five percent reduction from the products own 2011 baseline level. Our assessment is that this five percent reduction is appropriate and technologically feasible given the manufacturers' ability to apply similar technology packages with similar cost to what we have estimated for the primary program. For this purpose, the agencies do not see that potential obstacles are greater or lesser for engine standards which are based on the SET procedure or Heavy-duty FTP cycle. We do not believe this alternative needs to continue past 2016 since manufacturers will have had ample opportunity to benchmark competitive products and make appropriate changes to bring their product performance into line with the rest of the industry.

However, we are requesting comment on the potential to extend this regulatory alternative for one additional year for a single engine family with performance measured in that year as nine percent beyond the engine's own 2011 model year baseline level. We also request comment on the level of reduction beyond the baseline that is appropriate in this alternative. The five percent level reflects the aggregate improvement beyond the baseline we are requiring of the entire industry. As this provision is intended to address potential issues for legacy products that we would expect to be replaced or significantly improved at the manufacturer's next product change, we request comment if a two percent reduction would be more appropriate. We would consider two percent rather than five percent if we were convinced that making all of the changes we have outlined in our assessment of the technical feasibility of the standards was not possible for some engines due to legacy design issues that will change in the next design cycle. We are proposing that manufacturers making use of these provisions would need to exhaust all credits within this subcategory prior to using this flexibility and would not be able to generate emissions credits from other engines in the same regulatory subcategory as the engines complying using this alternate approach.

(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. Unlike the purpose-built heavy-duty diesel engines typical of this segment, these gasoline engines are developed for heavy-duty pickup trucks and vans primarily, but are also sold as loose engines to vocational vehicle manufacturers. Therefore, the agencies evaluated these engines in parallel with the heavy-duty pickup truck and van standard development. As with the pickup truck and van segment, the agencies anticipate that the manufacturers will have only one engine re-design within the 2014-18 model years under consideration within this proposal. In our meetings with all three of the major manufacturers in this 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 have concluded 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 proposing 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 proposed fuel consumption standard and EPA's proposed CO2 standard for heavy-duty gasoline engines are first effective in the 2016 model year.

The baseline 2010 model year CO2 performance of these heavy-duty gasoline engines over the Heavy-duty FTP cycle is 660 g CO2/bhp-hr (6.48 gal/100 bhp-hr) in 2010 based on non-GHG certification data provided to EPA by the manufacturers. The agencies propose that manufacturers achieve a five percent reduction in CO2 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. Additional detail on technology feasibility is included in Section III and in the draft RIA Chapter 2.

NHTSA is proposing a 7.05 gallon/100 bhp-hr standard for fuel consumption while EPA is proposing a 627 g CO2/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 subcategory to show compliance with both agencies' standards.

In the preceding section on diesel engines, we describe an alternative compliance approach for diesel engines based on improvements from an engine's own baseline of performance. We are not making a similar proposal for gasoline engines, but we request comment on the need for and appropriateness of such an approach. Comments suggesting the need for a Start Printed Page 74203similar approach should include specific recommendations on how the approach would work and the technical reasons why such an approach would be necessary in order to make the gasoline engine standards feasible.

(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 proposing would apply to individual vehicles and engines. NHTSA is not proposing to adopt in-use standards that would apply to the vehicles and engines in a similar fashion.

EPA is proposing 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 and fuel consumption results. EPA is proposing a 2 percent 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 and emission results obtained during subsequent in-use testing.

EPA is proposing 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 proposes that the existing engine useful life periods, as included in Table II-12, be broadened to include CO2 emissions and fuel consumption for both engines and tractors (see 40 CFR 86.004-2). While NHTSA proposes to 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.

EPA requests comments on the magnitude and need for an in-use adjustment factor for the engine standard and the compliance model GEM, based chassis standard.

(2) Test Procedures and Related Issues

The agencies are proposing test procedures to evaluate fuel consumption and CO2 emissions of vocational vehicles in a manner very similar to Class 7 and Class 8 combination tractors. This section describes a 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 on which the proposed standard 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 proposing to set separate engine and vehicle-based emission standards. For the vocational vehicles, engine manufacturers would be subject to the engine standards, and chassis manufacturers would be required to install certified engines in their chassis. The chassis manufacturer would be subject to a separate vehicle-based standard that would use the proposed truck simulation model to evaluate the impact of the tire design to determine compliance with the truck 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 proposing to evaluate fuel consumption and CO2 emissions respectively through a simulation of whole-vehicle operation, consistent with the NAS recommendation to use a truck model to evaluate truck performance. The agencies developed the GEM for the specific purpose of this proposal 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 agencies and proposed 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 are included in Chapter 4 of the draft RIA.

GEM is designed to focus on the inputs most closely associated with fuel consumption and CO2 emissions—i.e., on those which have the largest impacts such as aerodynamics, rolling resistance, weight, and others.

EPA and NHTSA have validated GEM based on the chassis test results from three SmartWay certified tractors tested at Southwest Research Institute. The validation work conducted on these three vehicles is representative of the other Class 7 and 8 tractors. Many Start Printed Page 74204aspects 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 is similar to the one used on a straight truck. Details of the validation testing and its representativeness are included in draft RIA Chapter 4. Overall, the GEM predicted the fuel consumption and CO2 emissions within 4 percent of the chassis test procedure results for three test cycles—the California ARB Transient cycle, the California ARB High Speed Cruise cycle, and the Low Speed Cruise cycle. These cycles are very similar to the ones the agencies are proposing to utilize in compliance testing. Test to test variation for heavy-duty vehicle chassis testing can be higher than 4 percent based on driver variation. The proposed simulation model is described in greater detail in draft RIA Chapter 4 and is available for download by interested parties at (http://www.epa.gov/​otaq/​). We request comment on all aspects of this approach to compliance determination in general and to the use of the GEM in particular.

The agencies are proposing 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. Tires are the only technology on which the agencies' own feasibility analysis for these vehicles is predicated. An example of the GEM input screen is included in Figure II-3. The input values for the simulation model would be derived by the manufacturer from tire test procedure proposed by the agencies in this proposal. The agencies are proposing that the remaining model inputs would be fixed values that are pre-defined by the agencies and are detailed in the draft RIA Chapter 4, including the engine fuel consumption map to be used in the simulation.

(b)Tire Rolling Resistance Assessment

As with the Class 7 and 8 combination tractors, NHTSA and EPA are proposing that the vocational vehicle's tire rolling resistance input to the GEM be determined using the ISO 28580:2009 test method.[83] The agencies believe the ISO test procedure is appropriate to propose for this program because the procedure is the same one used by the NHTSA tire fuel efficiency labeling program [84] and is consistent with the direction being taken by the tire industry both in the United States and Europe, and with the EPA SmartWay program. 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 vehicle. The results would be expressed as a rolling resistance coefficient and measured as kilogram per ton (kg/metric ton). The agencies are proposing 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 three tests would be the rolling resistance coefficient for the tire.

(c)Defined Vehicle Configurations in the GEM

As discussed above, the agencies are proposing a methodology that chassis manufacturers would use to quantify the tire rolling resistance values to be input into the GEM. Moreover, the agencies are proposing to define the remaining Start Printed Page 74205GEM inputs (i.e., specify them by rule), which may differ by the regulatory subcategory (for reasons described in the draft RIA). The defined inputs being proposed include the drive cycle, aerodynamics, truck curb weight, payload, engine characteristics, and drivetrain for each vehicle type, among others.

(i) Metric

Based on NAS's recommendation and feedback from the heavy-duty truck industry, NHTSA and EPA are proposing 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 trucks 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 CO2 vehicle standards would be represented as grams of CO2 per ton-mile.

(ii) Drive cycle

The drive cycle being proposed for the vocational vehicles consists of the same three modes proposed for the Class 7-8 combination tractors. The agencies are thus proposing the use of 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. However, we are proposing different weightings for each mode than proposed for Class 7 and 87 and 8 combination tractors, given the known difference in driving patterns between these two categories of vehicles. (The same reasoning underlies the agencies' proposal to use 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 two sources for mode weightings, as detailed in draft RIA Chapter 3. The agencies are proposing 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.[85] The proposed weighted CO2 and fuel consumption value consists of 37 percent of 65 mph Cruise, 21 percent of 55 mph Cruise, and 42 percent of Transient performance, which are reflected in the GEM.

(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 proposing to specify each of these aspects of the vehicle. The agencies developed the truck curb weight inputs based on industry information developed by ICF.[86] The proposed curb weights are 10,300 pounds for the LH trucks, 13,950 pounds for the MH trucks, and 29,000 pounds for the HH trucks.

NHTSA and EPA are also proposing the following payload requirement for each regulatory category. The payloads were developed from Federal Highway statistics based on averaging the payloads for the weight categories represented within each vehicle subcategory.[87] The proposed payload requirement is 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. Additional information is available in draft RIA Chapter 3.

(iv) Engine

As the agencies are proposing separate engine and truck 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 proposing to use fixed values that are pre-defined 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 truck that uses an engine with emissions and fuel consumption better than the standards would require fewer vehicle reductions than those being proposed. The agencies are proposing that the engine characteristics used in GEM be representative of a diesel engine, because it represents the largest fraction of engines in this market.

The agencies are proposing 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 CO2 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 CO2 emissions and fuel consumption standards and accounts for the increased stringency in the proposed MY 2017 standard). Effectively there is no change in stringency of the vocational vehicle standard (not including the engine) so that there is stability in the vocational vehicle (not including engine) standards for the full rulemaking period. These inputs are reasonable (indeed, seemingly necessitated) given the separate proposed 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 proposing to specify the engine's fuel consumption map, drive cycle, and payload; therefore, it makes sense to specify the drivetrain that matches.

In conclusion, for vocational vehicles, compliance would be determined by establishing values for the tire rolling resistance and using the prescribed inputs in GEM. The model would produce CO2 and fuel consumption results that would be compared against EPA's and NHTSA's respective standards.

(d) Engine Test Procedures

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 Start Printed Page 74206evaluation of vehicles.[88] An analogous metric for engines would be the amount of fuel consumed per unit of work. Thus, EPA is proposing that GHG emission standards for engines under the CAA would be expressed as g/bhp-hr: similarly, NHTSA's proposed fuel consumption standards under EISA would be represented as gallons of fuel per 100 horsepower-hour (gal/100 bhp-hr). EPA's metric is also consistent with EPA's current standards for non-GHG emissions for these engines.

EPA's criteria pollutant standards for engines 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. With regard to GHG and fuel consumption control, the agencies believe it is more 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.

As discussed above, 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 benefits. We further explained why the Heavy-duty FTP is the appropriate test cycle for engines used in vocational vehicles, and the steady-state SET procedure the most appropriate for engines used in combination tractors. We are not concerned if off-cycle manufacturers further calibrate these designs 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. For example, as noted earlier, turbocompounding is one technology that the agencies have identified as a likely approach for compliance with our proposed HHD SET standard described below. 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.

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 are proposing to exclude the CO2 emissions and fuel consumption increases due to regeneration from the calculation of the compliance levels over the defined test procedures. We considered including regeneration in the estimate of fuel consumption and GHG emissions and have 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 NOX emission standards cannot be met by engine designs that lead to frequent and extended 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 timeframe of this proposal. 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 CO2 emissions control and fuel consumption reductions than we will achieve by not including regeneration emissions. We are seeking comments regarding regeneration emissions and what approach if any the agencies should use in reflecting regeneration emissions in this program.

(e) Hybrid Powertrain Technology

Although the proposed 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 proposing to provide credits for the use of hybrid powertrain technology as described in Section IV. The agencies are proposing that any credits generated using such technologies could be applied to any heavy-duty vehicle or engine, and not be limited to the vehicle category generating the credit. Section IV below also details the proposed approach to account for the use of a hybrid powertrain when evaluating compliance with the truck standard. In general, manufacturers can derive the fuel consumption and CO2 emissions reductions based on comparative test results using the proposed chassis testing procedures. We are proposing the same three drive cycles and cycle weightings discussed for the vocational vehicles to evaluate trucks that use hybrid powertrains to power the vehicle during motive operation (such as pickup and delivery trucks and transit buses). However, we are proposing an additional PTO test cycle for trucks which use a PTO to power equipment while the vehicle is either idling or moving (such as bucket or refuse trucks). The reductions due to the hybrid technology would be calculated relative to the same type of vehicle with a conventional powertrain tested using the same protocol.

(3) Summary of Proposed Flexibility and Credit Provisions

EPA and NHTSA are proposing a number of flexibility provisions for vocational vehicle chassis manufacturers and engine manufacturers, as discussed in Section IV below. These provisions are all based on an averaging, banking and trading program for emissions and fuel consumption credits. They include provisions to encourage the introduction of advanced technologies such as hybrid drivetrains, provisions to Start Printed Page 74207incentivize early compliance with the proposed standards, and provisions to allow compliance using innovative technologies unanticipated by the agencies in developing this proposal.

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

EPA and NHTSA are proposing 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.[89] 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,[90] and therefore that the exemption will have a negligible impact on the GHG emissions and fuel consumption improvements from the proposed 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.[91] 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 proposed exemption from the standards established under this proposal 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 propose 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.

E. Other Standards Provisions

In addition to proposing CO2 emission standards for heavy-duty vehicles and engines, EPA is also proposing separate standards for N2 O and CH4 emissions.[92] NHTSA is not proposing comparable separate standards for these GHGs because they are not directly related to fuel consumption in the same way that CO2 is, and NHTSA's authority under EISA exclusively relates to fuel efficiency. N2 O and CH4 are important GHGs that contribute to global warming, more so than CO2 for the same amount of emissions due to their high Global Warming Potential (GWP).[93] EPA is proposing N2 O and CH4 standards which apply to HD pickup trucks and vans as well as to all heavy-duty engines. EPA is not proposing N2 O and CH4 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 is requesting comment in Section II.E.4 below on possible alternative CO2 equivalent approaches to provide near-term flexibility for 2012-14 MY light-duty vehicles.

Almost universally across current engine designs, both gasoline- and diesel-fueled, N2 O and CH4 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 nonmethane hydrocarbon (NMHC) and NOX control indirectly result in highly effective control of N2 O and CH4. 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 N2 O or CH4. Because of this, reductions in N2 O or CH4 beyond current levels in most heavy-duty applications would occur through the same mechanisms that result in NMHC and NOX 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 proposed “cap” standards. The proposed standards would act to cap emissions at today's levels to ensure that manufacturers maintain effective N2 O and CH4 emissions controls currently used should they choose a different technology path from what is currently used to control NMHC and NOX but also largely successful methods for controlling N2 O and CH4. As discussed below, some technologies that manufacturers may adopt for reasons other than reducing fuel consumption or GHG emissions could increase N2 O and CH4 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 proposing the same standards for all of the model years to which the rules apply.

EPA believes that the proposed N2 O and CH4 cap standards would 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 N2 O and CH4 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 CO2 eq emission values and combine them with CO2 into a single compliance value would also be appropriate, so long as it did not undermine the stringency of the CO2 standard. As described below, EPA is proposing that such an alternative Start Printed Page 74208compliance approach be available to manufacturers to provide certain flexibilities for different technologies.

EPA requests comments on the approach to regulating N2 O and CH4 emissions including the appropriateness of “cap” standards, the technical bases for the levels of the proposed N2 O and CH4 standards, the proposed test procedures, and the proposed timing for the standards. In addition, EPA seeks any additional emissions data on N2 O and CH4 from current technology engines.

EPA is basing its proposed N2 O and CH4 standards on available test data. We are soliciting 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 proposing that manufacturers should establish deterioration factors to ensure compliance throughout the useful life. We are not at this time aware of deterioration mechanisms for N2 O and CH4 that would result in large deterioration factors, but neither do we believe enough is known about these mechanisms to justify proposing assigned factors corresponding to no deterioration, as we are proposing for CO2, or for that matter to any predetermined level. We are therefore asking for comment on this subject.

In addition to N2 O and CH4 standards, this section also discusses air conditioning-related provisions and EPA's proposal to extend certification requirements to all-electric HD vehicles and vehicles and engines designed to run on ethanol fuel.

(1) What is EPA's proposed approach to controlling N2 O?

N2 O is a global warming gas with a GWP of 298. It accounts for about 0.3% of the current greenhouse gas emissions from heavy-duty trucks.[94]

N2 O is emitted from gasoline and diesel vehicles mainly during specific catalyst temperature conditions conducive to N2 O formation. Specifically, N2 O can be generated during periods of emission hardware warm-up when rising catalyst temperatures pass through the temperature window when N2 O formation potential is possible. For current heavy-duty gasoline engines with conventional three-way catalyst technology, N2 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. N2 O formation is generally only a concern with diesel and potentially with future gasoline lean-burn engines with compromised NOX emissions control systems. If the risk for N2 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 NOX control while allowing the formation of significant quantities of N2 O. However, these future advanced gasoline and diesel technologies do not inherently require N2 O formation to properly control NOX. Pathways exist today that meet criteria emission standards that would not compromise N2 O emissions in future systems as observed in current production engine and vehicle testing [95] 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 NOX and N2 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 N2 O formation, much like the path taken in current heavy-duty compliant engines and vehicles. Alternatively, manufacturers who find technologies that reduce criteria or CO2 emissions but see increases N2 O emissions beyond the cap could choose to offset N2 O emissions with reduction in CO2 as allowed in the proposed CO2 eq option discussed in Section II.E.3.

EPA is proposing an N2 O emission standard that we believe would be met by current-technology gasoline and diesel vehicles at essentially no cost. EPA believes that heavy-duty emission standards since 2008 model year, specifically the very stringent NOX standards for both engine and chassis certified engines, directly result in stringent N2 O control. It is believed that the current emission control technologies used to meet the stringent NOX standards achieve the maximum feasible reductions and that no additional technologies are recognized that would result in additional N2 O reductions. As noted, N2 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 N2 O can form is short. At the same time, we believe that the proposed standard would ensure that the design of advanced NOX control systems for future diesel and lean-burn gasoline vehicles would control N2 O emission levels. While current NOX control approaches used on current heavy-duty diesel vehicles do not compromise N2 O emissions and actually result in N2 O control, we believe that the proposed 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 N2 O emissions. Thus, the proposed standard would cap N2 O emission levels, with the expectation that current gasoline and diesel vehicle control approaches that comply with heavy-duty vehicle emission standards for NOX would not increase their emission levels, and that the cap would ensure that future diesel and lean-burn gasoline vehicles with advanced NOX controls would appropriately control their emissions of N2 O.

(a) Heavy-Duty Pickup Truck and Van N2 O Exhaust Emission Standard

EPA is proposing a per-vehicle N2 O emission standard of 0.05 g/mi, measured over the Light-duty FTP and HFET drive cycles. Similar to the CO2 standard approach, the N2 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 proposed CO2 emission requirements. Averaging between vehicles would not be allowed. The standard is designed to prevent increases in N2 O emissions from current levels, i.e., a no-backsliding standard.

The proposed N2 O level is approximately two times the average N2 O level of current gasoline and diesel heavy-duty trucks that meet the NOX standards effective since 2008 model year.[96] Manufacturers typically use design targets for NOX emission levels at approximately 50% 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 N2 O emission compliance. We are not proposing a more stringent Start Printed Page 74209standard for current gasoline and diesel vehicles because the stringent heavy-duty NOX standards already result in significant N2 O control, and we do not expect current N2O 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 proposed N2 O standard would require manufacturers to incorporate control strategies that minimize N2 O formation. Available approaches include using electronic controls to limit catalyst conditions that might favor N2 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 NOX control technologies already required to meet heavy-duty standards.

The light-duty GHG rule requires that manufacturers begin testing for N2 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 proposal.

Overall, we believe that manufacturers of HD pickups and vans (both gasoline and diesel) would meet the proposed 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 N2 O Exhaust Emission Standard

EPA is also proposing a per engine N2 O emissions standard of 0.05 g/bhp-hr for heavy-duty engines which become effective in 2014 model year. These standards remain the same over the useful life of the engine. The N2 O emissions would be measured over the Heavy-duty FTP cycle because it is believed that this cycle poses the highest risk for N2 O formation versus the additional heavy-duty compliance cycles. Averaging between vehicles would not be allowed. The standard is designed to prevent increases in N2 O emissions from current levels, i.e., a no-backsliding standard.

The proposed N2 O level is twice the average N2 O level of current diesel engines as demonstrated in the ACES Study and in EPA's testing of two additional engines with selective catalytic reduction aftertreatement systems.[97] Manufacturers typically use design targets for NOX emission levels of about 50% 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 N2 O emission compliance. EPA requests comment on the agency's technical assessment of current and potential future N2 O formation in heavy-duty engines, as presented here.

Engine emissions regulations do not currently require testing for N2 O. The Mandatory GHG Reporting final rule requires reporting of N2 O and requires that manufacturers either measure N2 O or use a compliance statement based on good engineering judgment in lieu of direct N2 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 proposing a consistent approach for heavy-duty engine manufacturers which allows them to delay direct measurement of N2 O until the 2015 model year. EPA welcomes comments on whether there are differences in the heavy-duty market which would warrant a different approach.

Manufacturers without the capability to measure N2 O by the 2015 model year would need to acquire and install appropriate measurement equipment in response to this proposed program. EPA has established four separate N2 O measurement methods, all of which are commercially available today. EPA expects that most manufacturers would use photo-acoustic measurement equipment, which EPA estimates would result in a one-time cost of about $50,000 for each test cell that would need to be upgraded.

Overall, EPA believes that manufacturers of heavy-duty engines, both gasoline and diesel, would meet the proposed standard without implementing any new technologies, and beyond relatively small facilities costs for any companies that still need to acquire and install N2 O measurement equipment, EPA does not project that manufacturers would incur significant costs associated with this proposed N2 O standard.

EPA is not proposing any vehicle-level N2 O standards for heavy-duty trucks (combination and vocational) in this proposal. The N2 O emissions would be controlled through the heavy-duty engine portion of the program. The only requirement of those truck manufacturers to comply with the N2 O requirements is to install a certified engine.

(2) What is EPA's proposed approach to controlling CH4?

CH4 is greenhouse gas with a GWP of 25. It accounts for about 0.03% of the greenhouse gases from heavy-duty trucks.[98]

EPA is proposing a standard that would cap CH4 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 CH4 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 CH4 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 proposal. Since CH4 is produced in gasoline and diesel engines similar to other hydrocarbon components, controls targeted at reducing overall NMHC levels generally also work at reducing CH4 emissions. Therefore, for gasoline and diesel vehicles, the heavy-duty hydrocarbon standards will generally prevent increases in CH4 emissions levels. CH4 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 CH4Start Printed Page 74210emissions 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 CH4 standards because, unlike other hydrocarbons, CH4 does not contribute significantly to ozone formation.[99] However, CH4 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 CH4, future emission levels of CH4 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 CH4 control can be as effective as gasoline or diesel equivalent vehicles, natural gas-fueled vehicles have historically produced significantly higher CH4 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 CH4 control by nature of the hydrocarbon controls, the heavy-duty standards do not require CH4 control and therefore some natural gas vehicle manufacturers have invested very little effort into methane control. While the proposed CH4 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 proposing more stringent CH4 standards because we believe that the controls used to meet current heavy-duty hydrocarbon standards should result in effective CH4 control when properly implemented. Since CH4 is already measured under the current heavy-duty emissions regulations (so that it may be subtracted to calculate NMHC), the proposed standard would not result in additional testing costs. EPA requests comment on whether the proposed cap standard would result in any significant technological challenges for manufacturers of natural gas vehicles.

(a) Heavy-Duty Pickup Truck and Van CH4 Standard

EPA is proposing a CH4 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 proposed CO2 standards. Similar to the CO2 standard approach, the CH4 emission level of a vehicle would be a composite of the Light-duty FTP and HFET cycles with the same 55% city weighting and 45% highway weighting.

The level of the proposed standard is approximately two times the average heavy-duty gasoline and diesel truck and van levels.[100] As with N2 O, this proposed level recognizes that manufacturers typically set emissions design targets with a compliance margin of approximately 50% of the standard. Thus, we believe that the proposed standard should be met by current gasoline vehicles with no increase from today's CH4 levels. Similarly, since current diesel vehicles generally have even lower CH4 emissions than gasoline vehicles, we believe that diesels would also meet the proposed standard with a larger compliance margin resulting in no change in today's CH4 levels.

(b) Heavy-Duty Engine CH4 Exhaust Emission Standard

EPA is proposing a heavy-duty engine CH4 emission standard of 0.05 g/hp-hr as measured on the Heavy-duty FTP, to apply beginning in model year 2014. The proposed standard would cap CH4 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 proposal (see 40 CFR 86.007-11).

The level of the proposed CH4 standard is twice the average CH4 emissions from the four diesel engines in the ACES study.[101] As with N2 O, this proposed level recognizes that manufacturers typically set emission design targets at about 50% of the standard. Thus, EPA believes the proposed standard would be met by current diesel and gasoline engines with little if any technological improvements. The agency believes a more stringent CH4 standard is not necessary due to effective CH4 controls in current heavy-duty technologies, since, as discussed above for N2 O, EPA believes that the challenge of complying with the CO2 standards should be the primary focus of the manufacturers.

CH4 is measured under the current 2007 regulations so that it may be subtracted to calculate NMHC. Therefore EPA expects that the proposed standard would not result in additional testing costs.

EPA is not proposing any vehicle-level CH4 standards for heavy-duty trucks (combination or vocational) in this proposal. The CH4 emissions would be controlled through the heavy-duty engine portion of the program. The only requirement of these truck manufacturers to comply with the CH4 requirements is to install a certified engine.

(3) Alternative CO2 Equivalent Option

If a manufacturer is unable to meet the N2 O or CH4 cap standards, EPA is proposing that the manufacturer may choose to comply using CO2 credits. In other words, a manufacturer could offset any N2 O emissions or any CH4 emissions by taking steps to further reduce CO2. A manufacturer choosing this option would convert its measured N2 O and CH4 test results in excess of the applicable standards into CO2 eq to determine the amount of CO2 credits required. For example, a manufacturer would use 25 Mg of positive CO2 credits to offset 1 Mg of negative CH4 credits or use 298 Mg of positive CO2 credits to offset 1 Mg of negative N2 O credits.[102] By using the Global Warming Potential of N2 O and CH4, the proposed approach recognizes the inter-correlation of these elements in impacting global warming and is environmentally neutral to meeting the proposed individual emissions caps.

The proposed NHTSA fuel consumption program will not use CO2 eq, as suggested above. Measured performance to the NHTSA fuel consumption standards will be based on the measurement of CO2 with no adjustment for N2 O and/or CH4. For manufacturers that use the EPA alternative CO2 eq credit, compliance to the EPA CO2 standard will not be directly equivalent to compliance to the NHTSA fuel consumption standard.Start Printed Page 74211

(4) Light-Duty Vehicle N2 O and CH4 Standards

For light-duty vehicles, as part of the MY 2012-2016 rulemaking, EPA finalized standards for N2 O and CH4 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 N2 O and CH4 were established to cap emissions and prevent future emissions increases, and were generally not expected to result in the application of new technologies for current vehicle designs or significant costs for the manufacturers. EPA also finalized an alternative CO2 equivalent standard option, which manufacturers may choose to use in lieu of complying with the otherwise-applicable N2 O and CH4 standards. The CO2-equivalent standard option allows manufacturers to fold all N2 O and CH4 emissions, on a CO2-equivalent basis, along with CO2 into their otherwise applicable CO2 emissions standard level. For flexible-fueled vehicles, the N2 O and CH4 standards must be met on both fuels (e.g., both gasoline and E-85).

EPA has learned since the standards were finalized that some manufacturers may have difficulty meeting the N2 O and/or CH4 standards in the early years of the program for a few of the vehicle models in their existing fleet. This is 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 CO2 equivalent alternative. On a CO2 equivalent basis, folding in all N2 O and CH4 emissions would add 3-4 g/mile or more to a manufacturer's overall fleet-average CO2 emissions level because the alternative standard must be used for the entire fleet, not just for the problem vehicles. 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. EPA believes this poses a legitimate issue of sufficiency of lead time in the short term (as well as an issue of cost, since EPA assumed that the N2 O and CH4 standards were essentially cost free) but expects that manufacturers would be able to make technology changes (e.g., calibration or catalyst changes) to the few vehicle models not currently meeting the N2 O and/or CH4 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 believes that it would be appropriate to provide additional flexibility in the near-term to allow manufacturers to meet the N2 O and CH4 standards. EPA requests comments on the option of allowing manufacturers to use the CO2 equivalent approach for one pollutant but not the other for their fleet—that is, allowing a manufacturer to fold in either CH4 or N2 O as part of the CO2-equivalent standard. For example, if a manufacturer is having trouble complying with the CH4 standard but not the N2 O standard, the manufacturer could use the N2 O equivalent option including CH4, but choose to comply separately with the applicable N2 O cap standard. EPA requests comments on allowing this approach in the light-duty program for MYs 2012-2014 as an additional flexibility to help manufacturers address any near-term issues that they may have with the N2 O and CH4 standards.

EPA also requests comments on possible alternative approaches of providing additional near-term flexibility. For example, as discussed in Section II.E above, EPA is proposing for HD vehicles and engines to allow manufacturers to use CO2 credits, on a CO2 equivalent basis, to offset N2 O and CH4 emissions above the applicable standard. EPA requests comment on whether this approach would be appropriate for the light-duty program as an additional flexibility. Again, the additional flexibility would be limited to MYs 2012-2014 for the reasons discussed above. EPA notes that, after considering all relevant comments, provisions to address this issue may be finalized in an action independent of the heavy-duty rulemaking process in the interest of finalizing the provisions as soon as possible to provide manufacturers with certainty for MY 2012 light-duty vehicles.

(5) EPA's Proposed 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.[103] This includes the direct leakage of refrigerant as well as the subsequent leakage associate with maintenance and servicing, and with disposal at the end of the vehicle's life.[104] The most commonly used refrigerant in automotive applications—R134a, has a high GWP of 1430.[105] 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 CO2 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 truck 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 CO2 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 proposing that truck manufacturers be required to 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 proposing 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.

EPA is proposing a leakage standard which is a “percent refrigerant leakage Start Printed Page 74212per 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 proposing a standard of 1.50 percent leakage per year for Heavy-duty Pickup Trucks and Vans and Class 7 and 87 and 8 Tractors. The proposed standard was derived from the vehicles with the largest system refrigerant capacity based on the Minnesota GHG Reporting database.[106] The average percent leakage per year of the 2010 model year vehicles is 2.7 percent. This proposed 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 is seeking comment on whether the stringency of a single “percent refrigerant leakage per year” standard fairly addresses the range of system refrigerant capacities likely to be used in heavy-duty trucks.[107] Since systems with less refrigerant may have a larger percentage of their annual leakage from the compressor shaft seal than systems with more refrigerant capacity, their relative percent refrigerant leakage per year could be higher, and a more extensive application of leakage reducing technologies could be needed to meet the standard). EPA welcomes comments relative to the stringency of the standard, and on whether manufacturers who adopt measures that improve the global warming impact of leakage emissions substantially beyond that achieved by the proposed standard should in some way be credited for this improvement.

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-GWP refrigerant. 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.[108] 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 does anticipate that updates to the SAE J2727 standard will be forthcoming (to address new materials and components which perform better than those originally used in the SAE analysis), and that it will be appropriate to include these updates in the regulations concerning refrigerant leakage.

Consistent with the 2012-2016 light-duty GHG 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. Time based learning is considered appropriate for A/C leakage control, so costs in the 2017 model year would 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 proposed rules.

EPA proposes that manufacturers demonstrate improvements in their A/C system designs and components through a design-based method. The proposed 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 proposed approach, manufacturers would choose from a menu of A/C equipment and components used in their vehicles in order to establish leakage scores, which would 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 GHG rule, EPA is proposing that a manufacturer would 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 proposed approach would 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 truck program, the total A/C leakage score would 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 would result in estimates of likely leakage emissions reductions that would be comparable to those that would eventually result from performance-based testing. At the same time, comments are encouraged on all developments that may lead to a robust, practical, performance-based test for measuring A/C refrigerant leakage emissions.

CO2 emissions are also associated with air conditioner efficiency, since air conditioners create load on the engine. See 74 FR 49529. However, EPA is not proposing to set air conditioning efficiency standards for vocational vehicles and combination tractors. The CO2 emissions due to air conditioning systems in these heavy-duty trucks are minimal compared to their overall emissions of CO2. For example, EPA conducted modeling of a Class 8 sleeper cab using GEM to evaluate the impact of air conditioning and found that it leads to approximately 1 gram of CO2/ton- mile. Therefore, a projected 24% improvement of the air conditioning system (the level projected in the light-duty GHG rulemaking), would only reduce CO2 emissions by less than 0.3 g CO2/ton-mile, or approximately 0.3 percent of the baseline Class 8 sleeper cab CO2 emissions.

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 GHG rule, where we require that manufacturers attest to the durability of Start Printed Page 74213components and systems used to meet the CO2 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

As just noted, 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 CO2 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.

Due to the complexity of the heavy-duty market, it is difficult to estimate with any degree of precision what the actual impact of indirect emissions are across the vastly different applications and duty cycles of heavy-duty trucks. Depending on application, geographic location and even seasonal usage relationships, A/C systems usage will vary differently across the heavy-duty fleet and therefore efficiency improvements will also result in different indirect emission reductions. Moreover, as just stated, indirect A/C emissions from vocational vehicles and combination tractors are very small relative to total GHG emissions from these vehicles. For these reasons, EPA is not proposing an indirect emission standard like we have proposed for direct emissions from heavy-duty vehicles.

Instead, EPA is seeking comment on the applicability of an indirect emissions credit for A/C system efficiency improvements specifically in the heavy-duty pickup trucks and vans (i.e., Class 2b and 3). These vehicles are most closely related to their light-duty counterparts that have an indirect emissions credit program established under the 2012-2016 MY Light-duty Vehicle Rule. It is likely that the light-duty and heavy-duty vehicles can share components used to improve the A/C system efficiency and reduce indirect A/C emissions. EPA also seeks comment on the level of the credit and if the fleet CO2 target standards should be adjusted accordingly to reflect expected A/C efficiency improvements similar to the approach used in the light-duty rule.

(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. We are proposing to revise 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 would 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 would remain optional for all criteria pollutants through the 2015 model year.

This change would primarily affect 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 would also be impacted, as they would need to comply with requirements for operation both on gasoline and ethanol.

We are proposing that the specific regulatory requirements for certification on ethanol follow those already established for methanol, such as certification to NMHC equivalent standards and waiver of certain requirements. We would 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 would also follow light-duty precedents, primarily calling on manufacturers to exercise good engineering judgment in applying the regulatory requirements, but would not be allowed to generate NOX or PM credits.

This proposed 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 proposed in connection with this proposed provision. We expect that there would be strong incentives for any manufacturers seeking to market these vehicles to also want them to be certified: (1) Uncertified vehicles would 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 would not be 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 would 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. EPA requests comment on this proposed application of its emission standards to HD vehicles and engines, regardless of the fuels they operate on.

III. Feasibility Assessments and Conclusions

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 proposed 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 proposed standards based on application of technology in light of the attribute based distinctions and related compliance measurement procedures. We also discuss consideration of standards that are either more or less stringent than those proposed.

This proposal 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. The decision on what standard to set is guided by each agency's statutory Start Printed Page 74214requirements, 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 proposed rulemaking.

Here, the focus of the standards is on applying fuel efficiency and emissions control technology to reduce fuel consumption, CO2 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 CO2 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 CO2 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 proposed 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. 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 CO2 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 the lead time required.

As described below, the vast majority of technology required by this proposal is commercially available and already being utilized to a limited extent across the fleet. Therefore the majority of the emission and fuel consumption reductions which would result from these proposed rules would result from the increased use of these technologies. EPA and NHTSA also believe that these proposed rules would 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 fundamental changes in the engine or trucks' performance. Put another way, none of the technology pathways underlying the proposed 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 Start Printed Page 74215vehicle cost to technologies which maintain freight utility.

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 fuel economy and GHG final 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 2012-2016 MY light-duty GHG 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 2008 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 draft RIA, rather than using the traditional Retail Price Equivalent (RPE) multiplier approach. For the heavy-duty pickup truck and van cost projections in this proposal, 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 proposal, 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.[109] 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.

Details of the direct and indirect costs, and all applicable ICMs, are presented in Chapter 2 of the draft RIA. In addition, for details on the ICMs, please refer to the RTI report that has been placed in the docket. The agencies request comment on all aspects of the cost analysis, including the adjustment factors used in the RTI analysis—the levels associated with R&D, warranty, etc.—and whether those are appropriate or should be revised. If commenters suggest revisions, the agencies request supporting arguments and/or documentation.

EPA and NHTSA believe that the emissions reductions called for by the proposed standards are technologically feasible at reasonable costs within the lead time provided by the proposed 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 agencies request comment on the methods and assumptions used to estimate costs, benefits, and technology cost-effectiveness for the main proposal and all of the alternatives. The agencies also seek comment on whether finalizing a different alternative stringency level for certain regulatory categories would be appropriate given agency estimates of costs and benefits.

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 draft RIA Chapter 2.

A. Class 7-8 Combination Tractor

Class 7 and 8 tractors are used in combination with trailers to transport freight.[110] The variation in the design of these tractors and their typical uses drive different technology solutions for each regulatory subcategory.

EPA and NHTSA collected information on the cost and effectiveness of fuel consumption and CO2 emission reducing technologies from several sources. The primary sources of information were the recent National Academy of Sciences report of Technologies and Approaches to Reducing the Fuel Consumption of Medium- and Heavy-Duty Vehicles,[111] TIAX's assessment of technologies to support the NAS panel report,[112] EPA's Heavy-duty Lumped Parameter Model,[113] the analysis conducted by the Northeast States Center for a Clean Air Future, International Council on Clean Transport, Southwest Research Institute and TIAX for reducing fuel consumption of heavy-duty long haul combination tractors (the NESCCAF/ICCT study),[114] and the technology cost analysis conducted by ICF for EPA.[115] 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 Start Printed Page 74216identified the potential cost of such technologies. The NAS panel contracted TIAX to perform an assessment of technologies and their associated capital costs which provide potential fuel consumption reductions in heavy-duty trucks and engines. 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 to specifically address the effectiveness and interactions of the proposed pickup truck and light heavy-duty engine technologies. The NESCAFF/ICCT study assessed technologies available in the 2012 through 2017 to reduce CO2 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 CO2 emissions and fuel consumption in heavy-duty engines, combination tractors, and vocational vehicles.

(1) What technologies did the agencies consider to reduce the CO2 emissions and fuel consumption of tractors?

Manufacturers can reduce CO2 emissions and fuel consumption of combination tractors through use of, among others, engine, aerodynamic, tire, extended idle, and weight reduction technologies. The standards are premised on use of these technologies. The agencies note that SmartWay trucks are available today which incorporate the technologies that the agencies are considering as the basis for the standards in this proposal. We will also discuss other technologies that could potentially be used, such as vehicle speed limiters, although we are not basing the proposed standards on their use for the model years covered by this proposal, 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 kinds of technologies that could be used to improve performance relative to this baseline.

(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 classic styling, or may be sold with conventional or SmartWay aerodynamic packages. Based on our review of current truck model configurations and Polk data provided through MJ Bradley,[116] we believe the aerodynamic configuration of the baseline new truck fleet is approximately 25 percent classic, 70 percent conventional, and 5 percent SmartWay (as these 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 “conventional” 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,[117] 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.

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.[118] The GEM demonstrates that an aerodynamic improvement of a Class 8 high roof sleeper cab with a Cd value from 0.60 (which represents a SmartWay tractor) provides a 5% reduction in fuel consumption and CO2 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% 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.[119] 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.[120] Low rolling resistance (LRR) drive tires are currently offered in both dual assembly and single wide-base configurations. Single wide tires can offer both the rolling resistance reduction along with improved aerodynamics and weight reduction. The GEM demonstrates that replacing baseline tractor tires with tires which meet the SmartWay level provides a 4% reduction in fuel consumption and CO2 emissions over the prescribed test cycle.

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, the agencies considered evaluating vehicle mass reductions on a total vehicle basis for tractors and vocational trucks.[121] The agencies considered defining a baseline vehicle curb weight and the GEM model 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 Start Printed Page 74217of this issue, including discussions with the industry, we decided it would not be possible to define a single vehicle baseline mass for the tractors and for vocational trucks 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 are proposing. We reflect mass reductions for specific technology substitutions (e.g., installing aluminum wheels instead of steel wheels) where we can 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 are accounting for mass reductions where we can accurately account for its benefits. In the future, if we are able to develop an appropriate vehicle mass baseline for the diversity of vehicles within a segment and therefore could reasonable project overall mass reductions that would not inadvertently reduce customer utility, we would consider setting standards that take into account overall vehicle mass reductions. The agencies' baseline tire and wheel package consists of dual tires with steel wheels. A tractor's empty curb weight can be reduced from the replacement of dual tires with single wide tires and with the replacement of steel wheels with high strength steel or aluminum. Analysis of literature indicates that there is opportunity to reduce typical tractor curb weights by 80 to 670 pounds, or up to roughly 3 percent, through the use of lighter weight wheels and single wide tires, as described in draft RIA Chapter 2. High strength steel, aluminum, and light weight aluminum alloys provide opportunities to reduce the truck's mass relative to steel wheels. In addition, single wide tires (a single wide-based tire which replaces two standard tires in each wheel position) provide the opportunity to reduce the overall mass of wheels and tires due to the replacement of dual tires with singles. On average, these technologies together can reduce weight by over 400 pounds. A weight reduction of this magnitude 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 for 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 CO2 emissions over the prescribed test cycle.

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.[122] EPA and NHTSA agree with the TIAX assessment of a 6 percent reduction in overall fuel consumption reduction.[123]

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, 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 will provide a 4 percent reduction in fuel consumption and CO2 emissions over the prescribed test cycles over a baseline vehicle without a VSL or one set above 65 mph.

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.[124] 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. While we believe there may be real benefits in reduced fuel consumption and GHG emissions through the application of automatic or automated manual transmission technology, we are not proposing to reflect that potential improvement in our standard setting nor in our compliance model. We have taken this approach because we cannot say with confidence what level of performance improvement to expect. However, we welcome comments on this decision supported where possible with data. If a clear measure of performance improvement can be defined for the use of automatic or automated manual transmission technologies, we will consider reflecting the technology in setting the stringency of the standards and in determining compliance with the standards.

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.[125] The light-duty fuel economy and GHG final 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. The agencies are interested in comments on whether low friction lubricants should be included in the technologies modeled in GEM to obtain certification values for fuel consumption and CO2 emissions and how manufacturers could ensure the use of these lubricants for the full useful life of the truck.

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, which are already included as a separate technology in the agencies' technology assessment. NAS estimated that hybrid systems would cost approximately $25,000 per truck in the 2015 through 2020 timeframe and Start Printed Page 74218provide a potential fuel consumption reduction of 10 percent, of which 6 percent is idle reduction which can be achieved through other idle reduction technologies.[126] 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 proposal, 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 draft 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 0.2 grams of NOX/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.

Engine performance for CO2 emissions and fuel consumption can be improved by use of the following technologies:

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.[127] 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.

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 NOX. Low-temperature EGR uses a larger or secondary EGR cooler to achieve lower intake charge temperatures, which tend to further reduce NOX formation. If the NOX 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.[128] 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 0.5 to 1.5 percent.[129]

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 are considering it as part of the baseline engine, as noted above). Because SCR is a highly effective NOX aftertreatment approach, it enables engines to be optimized to maximize fuel efficiency, rather than minimize engine-out NOX. 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.[130] As more effective low-temperature catalysts are developed, the NOX 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.[131] The agencies estimate an additional 1 to 2 percent reduction may be feasible in the 2017 model year through additional refinement.

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.[132]

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 Start Printed Page 74219speed, 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.[133]

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.[134] 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.[135]

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.[136] However, none of the bottoming cycle or Rankine engine systems has been demonstrated commercially and are currently in only the research stage.

(2) Projected Technology Package Effectiveness and Cost

(a) Class 7 and 8 Combination Tractors

EPA and NHTSA project that CO2 emissions and fuel consumption reductions can be feasibly and cost-effectively achieved in these rules' timeframes through the increased application of aerodynamic technologies, LRR tires, weight reduction, extended idle reduction technologies, vehicle speed limiters, and engine improvements. As discussed above, the agencies believe that hybrid powertrains in tractors will not be cost-effective in the time frame of the rules. The agencies also are not proposing to include drivetrain technologies in the standard setting process, as discussed in Section II.

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 proposed 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 GEM. 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 exhaust stacks at the B-pillar, which increase drag. The agencies consider a baseline truck as having “conventional” aerodynamic package, though today there is a large spread in aerodynamics in the new tractor fleet. As noted earlier, our assessment of the baseline new truck fleet aerodynamics represents approximately 25 percent classic, 70 percent conventional, and 5 percent SmartWay. This mix of vehicle aerodynamics provides a Cd performance level slightly greater than the “conventional aerodynamic package” Cd value (for example the baseline high roof tractor has a Cd of 0.69 while the same tractor category with a conventional aerodynamic package has a Cd of 0.68). 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.[137] The agencies use the inputs described in GEM to derive the baseline CO2 emissions and fuel consumption of Class 7 and 8 tractors. The results are included in Table III-2.

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(ii) Tractor Technology Package Effectiveness

The agencies' assessment of the proposed 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 technology performance characteristics for each subcategory, described below. Each technology consists of an input parameter which is in turn modeled in GEM. Table III-3 describes our proposed model inputs for the range of Class 7 and 8 tractor aerodynamic packages and vehicle technologies. This was combined with a projected technology application rate to determine the stringency of the proposed standard.

The aerodynamic packages are categorized as Classic, Conventional, SmartWay, Advanced SmartWay, and Advanced SmartWay II. The Classic aerodynamic package refers to traditional styling such as a flat front, exposed air cleaners and exhaust stacks, among others. The conventional package refers to an overall aerodynamic appearance and best represents the aerodynamics of the majority of new tractor sales. The SmartWay aerodynamic package includes technologies such as roof fairings, aerodynamic hoods, aerodynamic mirrors, chassis fairings, and cab extenders. The Advanced SmartWay and Advanced SmartWay II packages reflect different degrees of new aerodynamic technology development such as active air management. A more complete description of these aerodynamic packages is included in Chapter 2 of the draft RIA. In general, the coefficient of drag values for each package and tractor subcategory were developed from EPA's coastdown testing of tractor-trailer combinations, the 2010 NAS report, and SAE papers.

The rolling resistance coefficient for the tires was developed from SmartWay's tire testing to develop the SmartWay certification. The benefits for the extended idle reductions were developed from literature, SmartWay work, and the 2010 NAS report. The weight reductions were developed from manufacturer information.

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(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 proposed standards, NHTSA and EPA established technology application constraints. The first type of constraint was established based on the application of fuel consumption and CO2 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 proposed standards.

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 proposing 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.[139] EPA and NHTSA are proposing that 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 proposed standard is premised) to consist of 20 percent of Advanced SmartWay, 70 percent SmartWay, and 10 percent conventional reflecting our assessment of the fraction of tractors in this segment that can Start Printed Page 74222successfully apply these aerodynamic packages. The small percentage of conventional truck aerodynamics reflects applications including tractors serving as refuse haulers which spend a portion of their time off-road at the landfill and generally operate at lower speeds with frequent stops—further reducing the benefit of aggressive aerodynamic technologies. Features such as chassis skirts are prone to damage in off-road applications; therefore we are not proposing standards that are based on all trucks having chassis skirts or achieving GHG reductions premised on use of such technology. The 90 percent of tractors that we project can either be SmartWay or Advanced SmartWay equipped reflects the bulk of Class 8 high roof sleeper cab applications. We are not projecting a higher fraction of Advanced SmartWay 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. 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. We request comment on our assessment of the potential for use of Advanced SmartWay technologies and the need for a fraction of these vehicles to continue to remain configured as conventional cabs due to their occasional use off-road.

The proposed 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.[140] 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.

Trucks designed for on/off-road application may be restricted in the ability to improve the aerodynamic design of the bumper, chassis skirts, air cleaners, and other aspects of the truck which would typically be needed to move a conventional truck into the SmartWay bin. First, off-road applications may require the use of steel bumpers which tend to be less aerodynamic than plastic designs. Second, ground clearance may be an issue for some off road applications due to poor road surface quality. This may pose a greater likelihood that those items such as chassis skirts would incur damage in use and therefore would not be a technology desirable in these applications. Third, the trucks used in off-road applications may also experience dust which requires an additional air cleaner to manage the dirt. Fourth, some trucks are used in applications which require heavier load capacity, such as those with gross combined weights of greater than 80,000 pounds, which is today's Federal highway limit. Often these trucks are configured with different axle combinations than those traditionally used on-road. These trucks may contain either a lift axle or spread axle which allows for greater carrying capability. Both of these configurations limit the design and effectiveness of chassis skirts. Lastly, some work trucks require the use of PTO operation or access to equipment which may limit the application of side extenders and chassis skirts.

The agencies considered the on/off-road restriction to aerodynamic technology application, used VIUS estimate of approximately 35 percent of tractors may be used in this type of application, and used confidential data provided by truck manufacturers regarding the fraction of their current sales which go into the various applications, to project the aerodynamic application rates for each tractor category. For example, the agencies project that day cabs with low roofs will be used more often in these on/off-road applications than day cabs with high roof. Therefore, the agencies project technology application rate for conventional aerodynamics in day cab low roof as 40 percent while it would be 30 percent in day cab high roofs tractors. The agencies have also estimated that the development of advanced aerodynamic technologies would be applied first to high roof sleeper cabs and then follow with the other tractor categories. Therefore, the agencies propose to use a 10 percent application rate of the Advanced SmartWay aerodynamic technology package to the other tractor categories. The agencies welcome comment on our assessment of application rates and are interested in data that provide estimates on truck sales to the various applications where aerodynamics are less effective or restricted.

At least one LRR tire model is available today that meets the rolling resistance requirements of the SmartWay and Advanced SmartWay tire packages so the 2014 MY should afford manufacturers sufficient lead time to install these packages. However, tire rolling resistance is only one of 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 proposed standards should not be premised on 100 percent application of LRR tires in all tractor segments. The agencies are proposing to base their analyses on application rates that vary by category and match the application rates used for the aerodynamic packages to reflect the on/off-road application of some tractors which require a different balancing of traction versus rolling resistance. We believe on- versus off-road traction (primarily tread pattern) is the only tire performance parameter which trades off with tire rolling resistance so significantly that tire manufacturers would be unable to develop tires meeting both the assumed lower rolling resistance performance while maintaining or improving other characteristics of tire performance. We seek comment on our assessment.

Weight reductions can be achieved through single wide tires replacing dual tires and lighter weight wheel material. Single wide tires can reduce weight by over 160 pounds per axle. Aluminum wheels used in lieu of steel wheels will reduce weight by over 80 pounds for a dual wheel axle. Light weight aluminum steer wheels and aluminum single wide drive wheels and tires package available today would provide a 670 pound weight reduction over the baseline steel steer and dual drive wheels. The Start Printed Page 74223agencies recognize that not all tractors can or will use single wide tires, and therefore are proposing a weight reduction package of 400 pounds. The agencies are proposing to use a 100 percent application rate for this weight reduction package. The agencies are unaware of reasons why a combination of lower weight wheels or tires cannot be applied to all combination tractors, but welcome comments.

Idle reduction technologies provide significant reductions in fuel consumption and CO2 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 while providing certainty that the overnight idle operations will be eliminated. Therefore, we are allowing the installation of only an automatic engine shutoff, without override capability, to qualify for idle emission reductions in GEM to allow for aftermarket installations of idle reduction technology. We are proposing a 100 percent application rate for this technology for Class 8 sleeper cabs (note that the current fleet is estimated to have a 30 percent application rate). The agencies are unaware of reasons why extended idle reduction technologies could not be applied to all tractors with a sleeper cab, but welcome comments.

Vehicle speed limiters may be used as a technology to meet the standard, but in setting the standard we assumed a 0 percent application rate of vehicles speed limiters. Although we believe vehicles 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 at 55 mph for this customer. The resulting truck modeled in GEM could meet our proposed 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. We are seeking comment on the use of VSLs that cannot be overridden by the end-user as a means of compliance with our proposed standards.

We have chosen not to assume the use of a mandatory vehicle speed limiter in our proposal 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. Setting a mandatory expected use of such VSL carries the risk of requiring VSL in situations that are not appropriate from an efficiency perspective. To avoid such possibility, the agencies are not premising the proposed standards on use of VSL, and instead will rely on the industry to select VSL when circumstances are appropriate for its use. 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. We welcome comments on our decision not to premise the emission standards on the use of VSLs.

Table III-4 provides the proposed application rates of each technology broken down by weight class, cab configuration, and roof height.

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(iv) Derivation of the Proposed Tractor Standards

The agencies used the technology inputs and proposed technology application rates in GEM to develop the proposed fuel consumption and CO2 emissions standards for each subcategory of Class 7 and 8 combination tractors. The agencies derived a scenario truck for each subcategory by weighting the individual GEM input parameters included in Table III-3 by 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 proposed engine standards, the agencies assumed a compliant engine in GEM. In other words, EPA is proposing 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.[141] The agencies then ran GEM with a single set of vehicle inputs, as shown in Table III-5, to derive the proposed standards for each subcategory. Additional detail is provided in the draft RIA Chapter 2.

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The level of the 2014 and 2017 model year proposed standards and percent reduction from the baseline for each subcategory is included in Table III-6.

A summary of the proposed technology package costs is included in Table III-7 with additional details available in the draft RIA Chapter 2.

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(v) Reasonableness of the Proposed Standards

The proposed standards are based on aggressive application rates for control technologies which the agencies regard as the maximum feasible for the reasons given in Section (iii) above; see also draft RIA Chapter 2.5.8.2. These technologies, at the estimated application rates, are available within the lead time provided, as discussed in draft RIA Chapter 2.5. Use of these technologies would add only a small amount to the cost of the vehicle, and the associated reductions are highly cost effective, an estimated $10 per ton of CO2 eq per vehicle in 2030 without consideration of the substantial fuel savings.[142] This is even more cost effective than the estimated cost effectiveness for CO2 eq removal and fuel economy improvements under the light-duty vehicle rule, already considered by the agencies to be a highly cost effective reduction.[143] Moreover, the cost of controls is recovered due to the associated fuel savings, as shown in the payback analysis included in Table VIII-8 located in Section VIII below. Thus, overall cost per ton of the rule, considering fuel savings, is negative—fuel savings associated with the rule more than offset projected costs by a wide margin. See Table VIII-5 in Section VIII below. Given that the standards are technically feasible within the lead time afforded by the 2014 model year, are inexpensive and highly cost effective even without accounting for the fuel savings, and have no apparent adverse potential impacts (e.g., there are no projected negative impacts on safety or vehicle utility), the proposed standards represent a reasonable choice under section 202(a) of the CAA and under NHTSA's EISA authority at 49 U.S.C. 32902(k)(2).

(vi) Alternative Tractor Standards Considered

The agencies are not proposing tractor standards less stringent than the proposed standards because the agencies believe these standards are appropriate, highly cost effective, and technologically feasible within the rulemaking time frame. We welcome comments supplemented with data on each aspect of this determination most importantly on individual technology efficacy to reduce fuel consumption and GHGs as well was our estimates of individual technology cost and lead-time.

The agencies considered proposing tractor standards which are more stringent than those proposed reflecting increased application rates of the technologies discussed. We also considered setting more stringent standards based on the inclusion of hybrid powertrains in tractors. We stopped short of proposing more stringent standards based on higher application rates of improved aerodynamic controls and tire rolling resistance because we concluded that the technologies would not be compatible with the use profile of a subset of tractors which operate in offroad conditions. The agencies welcome comment on the application rates for each type of technology and for each tractor category. We have not proposed more stringent standards for tractors based on the use of hybrid vehicle technologies, believing that additional development and therefore lead-time is needed to develop hybrid systems and battery technology for tractors that operate primarily in highway cruise operations. We know, Start Printed Page 74227for example, that hybrid systems are being researched to capture and return energy for tractors that operate in gently rolling hills. However, it is not clear to us today that these systems will be generally applicable to tractors in the timeframe of this regulation. We seek comment on our assessment on the appropriateness of setting standards based on the use of hybrid technologies. Further, the agencies request comment supported by data regarding additional technologies not considered by the agencies in proposing these standards.

(b) Tractor Engines

(i) Baseline Engine Performance

As noted above, EPA and NHTSA developed the baseline medium and heavy heavy-duty diesel engine to represent a 2010 model year engine compliant with the 0.2 g/bhp-hr NOX standard for on-highway heavy-duty engines.

The agencies developed baseline SET values for medium and heavy heavy-duty diesel engines based on 2009 model year confidential manufacturer data and from testing conducted by EPA. The agencies adjusted the pre-2010 data to represent 2010 model year engine maps by using predefined technologies including SCR and other systems that are being used in current 2010 model year production. If an engine utilized did not meet the 0.2 g/bhp-hr NOX level, then the individual engine's CO2 result was adjusted to accommodate aftertreatment strategies that would result in a 0.2 g/bhp-hr NOX emission level as described in draft RIA Chapter 2.4.2.1. The engine CO2 results were then sales weighted within each regulatory subcategory to develop an industry average 2010 model year reference engine. While most of the engines fell within a few percent of this baseline at least one engine was more than six percent above this average baseline.

(ii) Engine Technology Package Effectiveness

The MHD and HHD diesel engine technology package for the 2014 model year includes engine friction reduction, improved aftertreatment effectiveness, improved combustion processes, and low temperature EGR system optimization. The agencies considered improvements in parasitic and friction losses through piston designs to reduce friction, improved lubrication, and improved water pump and oil pump designs to reduce parasitic losses. The aftertreatment improvements are available through lower backpressure of the systems and optimization of the engine-out NOX levels. Improvements to the EGR system and air flow through the intake and exhaust systems, along with turbochargers can also produce engine efficiency improvements. We note that individual technology improvements are not additive due to the interaction of technologies. The agencies assessed the impact of each technology over each of the 13 SET modes to project an overall weighted SET cycle improvement in the 2014 model year of 3 percent, as detailed in draft RIA Chapter 2.4.2.9 through 2.4.2.14. All of these technologies represent engine enhancements already developed beyond the research phase and are available as “off the shelf” technologies for manufacturers to add to their engines during the engine's next design cycle. We have estimated that manufacturers will be able to implement these technologies on or before the 2014 engine model year. The agencies proposal therefore reflects a 100 percent application rate of this technology package. The agencies gave consideration to proposing a more stringent standard based on the application of turbocompounding, a mechanical means of waste heat recovery, but concluded that manufacturers would have insufficient lead-time to complete the necessary product development and validation work necessary to include this technology across the industry by model year 2014.

As explained earlier, EPA's heavy-duty highway engine standards for criteria pollutants apply in three year increments. The heavy-duty engine manufacturer product plans have fallen into three year cycles to reflect these requirements. The agencies are proposing to set fuel consumption and CO2 emission standards recognizing the opportunity for technology improvements over this timeframe while reflecting the typical heavy-duty engine manufacturer product plan redesign and refresh cycles. Thus, the agencies are proposing to set a more stringent standard for heavy-duty engines beginning in the 2017 model year.

The MHDD and HHDD engine technology package for the 2017 model year includes the continued development of the 2014 model year technology package including refinement of the aftertreatment system plus turbocompounding. The agencies calculated overall reductions in the same manner as for the 2014 model year package. The weighted SET cycle improvements lead to a 6 percent reduction on the SET cycle, as detailed in draft RIA Chapter 2.4.2.12. The agencies' proposal is premised on a 100 percent application rate of this technology package. We gave consideration to proposing an even more stringent standard based on the use of advanced Rankine cycle (also called bottoming cycle) engine technology but concluded that there is insufficient lead-time between now and 2017 for this promising technology to be developed and applied generally to all heavy-duty engines.[144] Therefore, these technologies were not included in determining the stringency of the proposed standards. However, we do believe the bottoming cycle approach represents a significant opportunity to reduce fuel consumption and GHG emissions in the future. EPA and NHTSA are therefore both proposing provisions described in Section IV to create incentives for manufacturers to Start Printed Page 74228continue to invest to develop this technology.

(iii) Derivation of Engine Standards

EPA developed the proposed 2014 model year CO2 emissions standards (based on the SET cycle) for diesel engines by applying the three percent reduction from the technology package (just explained above) to the 2010 model year baseline values determined using the SET cycle. EPA developed the 2017 model year CO2 emissions standards for diesel engines while NHTSA similarly developed the 2017 model year diesel engine fuel consumption standards by applying the 6 percent reduction from the 2017 model year technology package (reflecting performance of turbocompounding plus the 2014 MY technology package) to the 2010 model year baseline values. The proposed standards are included in Table III-9.

(iv) Engine Technology Package Costs

EPA has historically used two different approaches to estimate the indirect costs (sometimes called fixed costs) of regulations including costs for product development, machine tooling, new capital investments and other general forms of overhead that do not change with incremental changes in manufacturing volumes. Where the Agency could reasonably make a specific estimate of individual components of these indirect costs, EPA has done so. Where EPA could not readily make such an estimate, EPA has instead relied on the use of markup factors referred to as indirect cost multipliers (ICMs) to estimate these indirect costs as a ratio of direct manufacturing costs. In general, EPA has used whichever approach it believed could provide the most accurate assessment of cost on a case by case basis. The agencies' general approach used elsewhere in this proposal (for HD pickup trucks, gasoline engines, combination tractors, and vocational vehicles) estimates indirect costs based on the use of ICMs. See also 75 FR 25376. We have used this approach generally because these standards are based on installing new parts and systems purchased from a supplier. In such a case, the supplier is conducting the bulk of the research and development on the new parts and systems and including those costs in the purchase price paid by the original equipment manufacturer. In this situation, we believe that the ICM approach provides an accurate and clear estimate of the additional indirect costs borne by the manufacturer.

For the heavy-duty diesel engine segment, however, the agencies do not consider this model to be the most appropriate because the primary cost is not expected to be the purchase of parts or systems from suppliers or even the production of the parts and systems, but rather the development of the new technology by the original equipment manufacturer itself. Most of the technologies the agencies are projecting the heavy-duty engine manufacturers will use for compliance reflect modifications to existing engine systems rather than wholesale addition of technology (e.g., improved turbochargers rather than adding a turbocharger where it did not exist before as was done in our light-duty joint rulemaking in the case of turbo-downsizing). When the bulk of the costs come from refining an existing technology rather than a wholesale addition of technology, a specific estimate of indirect costs may be more appropriate. For example, combustion optimization may significantly reduce emissions and cost a manufacturer millions of dollars to develop but will lead to an engine that is no more expensive to produce. Using a bill of materials approach would suggest that the cost of the emissions control was zero reflecting no new hardware and ignoring the millions of dollars spent to develop the improved combustion system. Details of the cost analysis are included in the draft RIA Chapter 2.

The agencies developed the engineering costs for the research and development of diesel engines with lower fuel consumption and CO2 emissions. The aggregate costs for engineering hours, technician support, dynamometer cell time, and fabrication of prototype parts are estimated at $6,750,000 per manufacturer per year over the five years covering 2012 through 2016. In aggregate, this averages out to $280 per engine during 2012 through 2016 using an annual sales value of 600,000 light-, medium- and heavy-HD engines. The agencies also are estimating costs of $100,000 per engine manufacturer per engine class (light-, medium- and heavy-HD) to cover the cost of purchasing photo-acoustic measurement equipment for two engine test cells. This would be a one-time cost incurred in the year prior to implementation of the standard (i.e., the cost would be incurred in 2013). In aggregate, this averages out to $4 per engine in 2013 using an annual sales value of 600,000 light-, medium- and heavy-HD engines.

Where we projected that additional new hardware was needed to the meet the proposed standards, we developed the incremental costs for those technologies and marked them up using the ICM approach. Table III-10 below summarizes those estimates of cost on a per item basis. All costs shown in Table III-18 include a low complexity ICM of 1.11 and time based learning is considered applicable to each technology.

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The overall diesel engine technology package cost for a medium HD engine being placed in a combination tractor is $223 in the 2014 model year and $1,027 in the 2017 model year; for a heavy HD engine being placed in a combination tractor these costs are $145 and $955 in the 2014 and 2017 model years, respectively. The differences for the medium HD engines are the valve train friction reduction costs of $78 in 2014 ($71 in 2017) that are not applied to heavy HD engines.

(v) Reasonableness of the Proposed Standards

The proposed engine standards appear to be reasonable and consistent with the agencies' respective statutory authorities. With respect to the 2014 and 2017 MY standards, all of the technologies on which the standards are predicated have already been demonstrated in some capacity and their effectiveness is well documented. The proposal reflects a 100 percent application rate for these technologies. The costs of adding these technologies remain modest across the various engine classes as shown in Table III-10. Use of these technologies would add only a small amount to the cost of the vehicle,[145] and the associated reductions are highly cost effective, an estimated $6 per ton of CO2 eq per vehicle.[146] This is even more cost effective than the estimated cost effectiveness for CO2 eq removal under the light-duty vehicle rule, already considered by the agencies to be a highly cost effective reduction.[147] Even the more expensive 2017 MY proposed standard still represents only a small fraction of the vehicle's total cost and is even more cost effective than the light-duty vehicle rule. Moreover, costs are more than offset by fuel savings. Accordingly, EPA and NHTSA view these standards as reflecting an appropriate balance of the various statutory factors under section 202(a) of the CAA and under NHTSA's EISA authority at 49 U.S.C. 32902(k)(2).

(vi) Temporary Alternative Standard for Certain Engine Families

As discussed above in Section II.B (1)(b), notwithstanding the general reasonableness of the proposed standards, the agencies recognize that heavy-duty engines have never been subject to GHG or fuel consumption (or fuel economy) standards and that such control has not necessarily been an independent priority for manufacturers. The result is that there are a group of legacy engines with emissions higher than the industry baseline for which compliance with the proposed 2014 MY standards may be more challenging and for which there may simply be inadequate lead time. The issue is not whether these engines' GHG and fuel consumption performance cannot be improved by utilizing the technology packages on which the proposed standards are based. Those technologies can be utilized by all engines and the same degree of reductions obtained. Rather the underlying base engine components of these engines reflect designs that are decades old and therefore have base performance levels below what is typical for the industry as a whole today. Manufacturers have been gradually replacing these legacy products with new engines. Engine Start Printed Page 74230manufacturers have indicated to the agencies they will have to align their planned replacement of these products with our proposed standards and at the same time add additional technologies beyond those identified by the agencies as the basis for the proposed standard. Because these changes will reflect a larger degree of overall engine redesign, manufacturers may not be able to complete this work for all of their legacy products prior to model year 2014. To pull ahead these already planned engine replacements would be impossible as a practical matter given the engineering structure and lead-times inherent in the companies' existing product development processes. We have also concluded that the use of fleet averaging would not address the issue of legacy engines because each manufacturer typically produces only a limited line of MHDD and HHDD engines. (Because there are ample fleetwide averaging opportunities for heavy-duty pickups and vans, the agencies do not perceive similar difficulties for these vehicles.)

Facing a similar issue in the light-duty vehicle rule, EPA adopted a Temporary Lead Time Allowance provision whereby a limited number of vehicles of a subset of manufacturers would meet an alternative standard in the early years of the program, affording them sufficient lead time to meet the more stringent standards applicable in later model years. See 75 FR 25414-25418. The agencies are proposing a similar approach here. As explained above in Section II B. (1) (b), the agencies are proposing a regulatory alternative whereby a manufacturer, for a limited period, would have the option to comply with a unique standard requiring the same level of reduction of emissions (i.e., percent removal) and fuel consumption as otherwise required, but the reduction would be measured from its own 2011 model year baseline. We are thus proposing an optional standard whereby manufacturers would elect to have designated engine families meet a standard of 3% reduction from their 2011 baseline emission and fuel consumption levels for that engine family. Our assessment is that this three percent reduction is appropriate based on use of similar technology packages at similar cost as we have estimated for the primary program. As explained earlier, we are not proposing that the option to select an alternative standard continues past the 2016 MY. By this time, the engines should have gone through a redesign cycle which will allow manufacturers to replace those legacy engines which resulted in abnormally high baseline emission and fuel consumption levels and to achieve the MY 2017 standards which would be feasible using the technology package set out above (optimized NOX aftertreatment, improved EGR, reductions in parasitic losses, and turbocharging). Manufacturers would, of course, be free to adopt other technology paths which meet the proposed MY 2017 standards.

Since the alternative standard is premised on the need for additional lead time, manufacturers would first have to utilize all available flexibilities which could otherwise provide that lead time. Thus, the alternative would not be available unless and until a manufacturer had exhausted all available credits and credit opportunities, and engines under the alternative standard could not generate credits. See 75 FR 25417-25419 (similar approach for vehicles which are part of Temporary Lead Time Allowance under the light-duty vehicle rule). We are proposing that manufacturers can select engine families for this alternative standard without agency approval, but are proposing to require that manufacturers notify the agency of their choice and to include in that notification a demonstration that it has exhausted all available credits and credit opportunities. Manufacturers would also have to demonstrate their 2011 baseline calculations as part of the certification process for each engine family for which the manufacturer elects to use the alternative standard. See Section V.C.1(b)(i) below.

(vii) Alternative Engine Standards Considered

The agencies are not proposing engine standards less stringent than the proposed standards because the agencies believe these proposed standards are appropriate, highly cost effective, and technologically feasible, as just described. We welcome comments supplemented with data on each aspect of this determination most importantly on individual engine technology efficacy to reduce fuel consumption and GHG emissions. Comments should also address our estimates of individual technology cost and lead-time.

The agencies considered proposing engine standards which are more stringent. Since the proposed standards reflect 100 percent utilization of the various technology packages, some additional technology would have to be added. The agencies are proposing 2017 model year standards based on the use of turbocompounding. The agencies considered the inclusion of more advanced heat recovery systems, such as Rankine or bottoming cycles, which would provide further reductions. However, the agencies are not proposing this level of stringency because our assessment is that these technologies would not be available for production by the 2017 model year. The agencies welcome comments on whether waste heat recovery technologies are appropriate to consider for the 2017 model year standard, or if not, then when would they be appropriate.

B. Heavy-Duty Pickup Trucks and Vans

This section describes the process the agencies used to develop the standards the agencies are proposing for HD pickups and vans. We started by gathering available information about the fuel consumption and CO2 emissions from recent model year vehicles. The core portion of this information comes primarily from EPA's certification databases, CFEIS and VERIFY, which contain the publicly available data [148] regarding emission and fuel economy results. This information is not extensive because manufacturers have not been required to chassis test HD diesel vehicles for EPA's criteria pollutant emissions standards, nor have they been required to conduct any testing of heavy-duty vehicles on the highway cycle. Nevertheless, enough certification activity has occurred for diesels under EPA's optional chassis-based program, and, due to a California NOX requirement for the highway test cycle, enough test results have been voluntarily reported for both diesel and gasoline vehicles using the highway test cycle, to yield a reasonably robust data set. To supplement this data set, for purposes of this rulemaking EPA initiated its own testing program using in-use vehicles. This program and the results from it thus far are described in a memorandum to the docket for this rulemaking.[149]

Heavy-duty pickup trucks and vans are sold in a variety of configurations to meet market demands. Among the differences in these configurations that affect CO2 emissions and fuel consumption are curb weight, GVWR, axle ratio, and drive wheels (two-wheel drive or four-wheel drive). Because the currently-available test data set does not capture all of these configurations, it is necessary to extend that data set across the product mix using adjustment factors. In this way a test result from, say a truck with two-wheel drive, 3.73:1 axle ratio, and 8000 lb test weight, can Start Printed Page 74231be used to model emissions and fuel consumption from a truck of the same basic body design, but with 4wd, a 4.10:1 axle ratio, and 8,500 lb test weight. The adjustment factors are based on data from testing in which only the parameters of interest are varied. These parameterized adjustments and their basis are also described in a memorandum to the docket for this rulemaking.[150]

The agencies requested and received from each of the three major manufacturers confidential information for each model and configuration, indicating the values of each of these key parameters as well as the annual production (for the U.S. market). Production figures are useful because, under our proposed standards for HD pickups and vans, compliance is judged on the basis of production-weighted (corporate average) emissions or fuel consumption level, not individual vehicle levels. For consistency and to avoid confounding the analysis with data from unusual market conditions in 2009, the production and vehicle specification data is from the 2008 model year. We made the simplifying assumption that these sales figures reasonably approximate future sales for purposes of this analysis.

One additional assessment was needed to make the data set useful as a baseline for the standards selection. Because the appropriate standards are determined by applying efficiency-improving technologies to the baseline fleet, it is necessary to know the level of penetration of these technologies in the latest model year (2010). This information was also provided confidentially by the manufacturers. Generally, the agencies found that the HD pickup and van fleet was at a roughly consistent level of technology application, with (1) the transition from 4-speed to 5- or 6-speed automatic transmissions mostly accomplished, (2) coupled cam phasing to achieve variable valve control on gasoline engines likewise mostly in place, and (3) substantial remaining potential for optimizing catalytic diesel NOX aftertreatment to improve fuel economy (the new heavy-duty NOX standards having taken effect in the 2010 model year).

Taking this 2010 baseline fleet, and applying the technologies determined to be feasible and appropriate by the 2018 model year, along with their effectiveness levels, the agencies could then make a determination of appropriate proposed standards. The assessment of feasibility, described immediately below, takes into account the projected costs of these technologies. The derivation of these costs, largely based on analyses developed in the light-duty GHG and fuel economy rulemaking, are described in Section III.B(3).

Our assessment concluded that the technologies that the agencies considered feasible and appropriate for HD pickups and vans could be consistently applied to essentially all vehicles across this sector by the 2018 model year. Therefore we did not apply varying penetration rates across vehicle types and models in developing and evaluating the proposed standards.

Since the manufacturers of HD pickups and vans generally only have one basic pick-up truck and van with different versions ((i.e., different wheel bases, cab sizes, two-wheel drive, four-wheel drive, etc.) and do not have the flexibility of the light-duty fleet to coordinate model improvements over several years, changes to the HD pickups and vans to meet new standards must be carefully planned with the redesign cycle taken into account. The opportunities for large-scale changes (e.g., new engines, transmission, vehicle body and mass) thus occur less frequently than in the light-duty fleet, typically at spans of 8 or more years. However, opportunities for gradual improvements not necessarily linked to large scale changes can occur between the redesign cycles. Examples of such improvements are upgrades to an existing vehicle model's engine, transmission and aftertreatment systems. Given this long redesign cycle and our understanding with respect to where the different manufacturers are in that cycle, the agencies have initially determined that the full implementation of the proposed standards would be feasible and appropriate by the 2018 model year.

Although we did not determine that it was necessary for feasibility to apply varying technology penetration levels to different vehicles, we did decide that a phased implementation schedule would be appropriate to accommodate manufacturers' redesign workload and product schedules, especially in light of this sector's relatively low sales volumes and long product cycles. We did not determine a specific cost of implementing the final standards immediately in 2014 without a phase-in, but we assessed it to be much higher than the cost of the phase-in we are proposing, due to the workload and product cycle disruptions it would cause, and also due to manufacturers' resulting need to develop some of these technologies for heavy-duty applications sooner than or simultaneously with light-duty development efforts. See generally 75 FR 25467-25468 explaining why attempting major changes outside the redesign cycle period raises very significant issues of both feasibility and cost. On the other hand, waiting until 2018 before applying any new standards could miss the opportunity to achieve meaningful and cost-effective early reductions not requiring a major product redesign when the largest changes and reductions are expected to occur.

The proposed phase-in schedule, 15-20-40-60-100 percent in 2014-2015-2016-2017-2018, respectively, was chosen to strike a balance between meaningful reductions in the early years (reflecting the technologies' penetration rates of 15 and 20 percent) and providing manufacturers with needed lead time via a gradually accelerating ramp-up of technology penetration.[151] By expressing the proposed phase-in in terms of increasing fleetwide stringency for each manufacturer, while also providing for credit generation and use (including averaging, carry-forward, and carry-back), we believe our proposal affords manufacturers substantial flexibility to satisfy the phase-in through a variety of pathways: the gradual application of technologies across the fleet (averaging a fifth of total production in each year), greater application levels on only a portion of the fleet, or a mix of the two.

We considered setting more stringent standards that would require the application of additional technologies by 2018. We expect, in fact, that some of these technologies may well prove feasible and cost-effective in this timeframe, and may even become technologies of choice for individual manufacturers. This dynamic has played out in EPA programs before and highlights the value of setting performance-based standards that leave engineers the freedom to find the most cost-effective solutions.

However, the agencies do believe that at this stage there is not enough information to conclude that the additional technologies provide an appropriate basis for standard-setting. For example, we believe that 42V stop-start systems can be applied to gasoline vehicles with significant GHG and fuel Start Printed Page 74232consumption benefits, but we recognize that there is uncertainty at this time over the cost-effectiveness of these systems in heavy-duty applications, and over customer acceptance of vehicles with high GCWR towing large loads that would routinely stop running at idle. Hybrid electric technology likewise could be applied to heavy-duty vehicles, and in fact has already been so applied on a limited basis. However, the development, design, and tooling effort needed to apply this technology to a vehicle model is quite large, and seems less likely to prove cost-effective in this timeframe, due to the small sales volumes relative to the light-duty sector. Here again, potential customer acceptance would need to be better understood because the smaller engines that facilitate much of a hybrid's benefit are typically at odds with the importance pickup trucks buyers place on engine horsepower and torque, whatever the vehicle's real performance.

We also considered setting less stringent standards calling for a more limited set of applied technologies. However, our assessment concluded with a high degree of confidence that the technologies on which the proposed standards are premised are clearly available at reasonable cost in the 2014-2018 timeframe, and that the phase-in and other flexibility provisions allow for their application in a very cost-effective manner, as discussed in this section below.

More difficult to characterize is the degree to which more or less stringent standards might be appropriate because of under- or over-estimating effectiveness of the technologies whose performance is the basis of the proposed standards. Our basis for these estimates is described in Section III.B.(1)(1) . Because for the most part these technologies have not yet been applied to HD pickups and vans, even on a limited basis, we are relying to some degree on engineering judgment in predicting their effectiveness. Even so, we believe that we have applied this judgment using the best information available, primarily from our recent rulemaking on light-duty vehicle GHGs and fuel economy, and have generated a robust set of effectiveness values.

We solicit comment and new information that would aid the agencies in establishing the appropriate level of stringency for the HD pickup and van standards, and on all facets of the assessment described here and elsewhere in these rulemaking proposals.

(1) What technologies did the agencies consider?

The agencies considered over 35 vehicle technologies that manufacturers could use to improve the fuel consumption and reduce CO2 emissions of their vehicles during MYs 2014-2018. The majority of the technologies described in this section is readily available, well known, and could be incorporated into vehicles once production decisions are made. Other technologies considered may not currently be in production, but are beyond the research phase and under development, and are expected to be in production in highway vehicles over the next few years. These are technologies which are capable of achieving significant improvements in fuel economy and reductions in CO2 emissions, at reasonable costs. The agencies did not consider technologies in the research stage because there is insufficient time for such technologies to move from research to production during the model years covered by this proposal.

The technologies considered in the agencies' analysis are briefly described below. They fall into five broad categories: Engine technologies, transmission technologies, vehicle technologies, electrification/accessory technologies, and hybrid technologies.

In this class of trucks and vans, diesel engines are installed in about half of all vehicles. The ratio between gasoline and diesel engine purchases by consumers has tended to track changes in the overall cost of oil and the relative cost of gasoline and diesel fuels. When oil prices are higher, diesel sales tend to increase. This trend has reversed when oil prices fall or when diesel fuel prices are significantly higher than gasoline. In the context of our technology discussion for heavy-duty pickups and vans, we are treating gasoline and diesel engines separately so each has a set of baseline technologies. We discuss performance improvements in terms of changes to those baseline engines. Our cost and inventory estimates contained elsewhere reflect the current fleet baseline with an appropriate mix of gasoline and diesel engines. Note that we are not basing the proposed standards on a targeted switch in the mix of diesel and gasoline vehicles. We believe our proposed standards require similar levels of technology development and cost for both diesel and gasoline vehicles. Hence the proposed program does not force, nor does it discourage, changes in a manufacturer's fleet mix between gasoline and diesel vehicles. Although we considered setting a single standard based on the performance level possible for diesel vehicles, we are not proposing such an approach because the potential disruption in the HD pickup and van market from a forced shift would not be justified. Types of engine technologies that improve fuel efficiency and reduce CO2 emissions include the following:

  • Low-friction lubricants—low viscosity and advanced low friction lubricant oils are now available with improved performance and better lubrication. If manufacturers choose to make use of these lubricants, they would need to make engine changes and possibly conduct durability testing to accommodate the low-friction lubricants.
  • Reduction of engine friction losses—can be achieved through low-tension piston rings, roller cam followers, improved material coatings, more optimal thermal management, piston surface treatments, and other improvements in the design of engine components and subsystems that improve engine operation.
  • Cylinder deactivation—deactivates the intake and exhaust valves and prevents fuel injection into some cylinders during light-load operation. The engine runs temporarily as though it were a smaller engine which substantially reduces pumping losses.
  • Variable valve timing—alters the timing of the intake valve, exhaust valve, or both, primarily to reduce pumping losses, increase specific power, and control residual gases.
  • Stoichiometric gasoline direct-injection technology—injects fuel at high pressure directly into the combustion chamber to improve cooling of the air/fuel charge within the cylinder, which allows for higher compression ratios and increased thermodynamic efficiency.
  • Diesel engine improvements and diesel aftertreatment improvements—improved EGR systems and advanced timing can provide more efficient combustion and, hence, lower fuel consumption. Aftertreatment systems are a relatively new technology on diesel vehicles and, as such, improvements are expected in coming years that allow the effectiveness of these systems to improve while reducing the fuel and reductant demands of current systems.

Types of transmission technologies considered include:

  • Improved automatic transmission controls—optimizes shift schedule to maximize fuel efficiency under wide ranging conditions, and minimizes losses associated with torque converter slip through lock-up or modulation.Start Printed Page 74233
  • Six-, seven-, and eight-speed automatic transmissions—the gear ratio spacing and transmission ratio are optimized for a broader range of engine operating conditions.

Types of vehicle technologies considered include:

  • Low-rolling-resistance tires—have characteristics that reduce frictional losses associated with the energy dissipated in the deformation of the tires under load, therefore improving fuel efficiency and reducing CO2 emissions.
  • Aerodynamic drag reduction—is achieved by changing vehicle shape or reducing frontal area, including skirts, air dams, underbody covers, and more aerodynamic side view mirrors.
  • Mass reduction and material substitution—Mass reduction encompasses a variety of techniques ranging from improved design and better component integration to application of lighter and higher-strength materials. Mass reduction is further compounded by reductions in engine power and ancillary systems (transmission, steering, brakes, suspension, etc.). The agencies recognize there is a range of diversity and complexity for mass reduction and material substitution technologies and there are many techniques that automotive suppliers and manufacturers are using to achieve the levels of this technology that the agencies have modeled in our analysis for this proposal.

Types of electrification/accessory and hybrid technologies considered include:

  • Electric power steering and Electro-Hydraulic power steering—are electrically assisted steering systems that have advantages over traditional hydraulic power steering because it replaces a continuously operated hydraulic pump, thereby reducing parasitic losses from the accessory drive.
  • Improved accessories—may include high efficiency alternators, electrically driven (i.e., on-demand) water pumps and cooling fans. This excludes other electrical accessories such as electric oil pumps and electrically driven air conditioner compressors.
  • Air Conditioner Systems—These technologies include improved hoses, connectors and seals for leakage control. They also include improved compressors, expansion valves, heat exchangers and the control of these components for the purposes of improving tailpipe CO2 emissions as a result of A/C use.[152]

How did the agencies determine the costs and effectiveness of each of these technologies?

Building on the technical analysis underlying the 2012-2016 MY light-duty vehicle rule, the agencies took a fresh look at technology cost and effectiveness values for purposes of this proposal. For costs, the agencies reconsidered 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 (BOM) approach employed by NHTSA and EPA in the light-duty rule.

For two technologies, stoichiometric gasoline direct injection (SGDI) and turbocharging with engine downsizing, the agencies relied to the extent possible on the available tear-down data and scaling methodologies used in EPA's ongoing study with FEV, Incorporated. This study consists of complete system tear-down to evaluate technologies down to the nuts and bolts to arrive at very detailed estimates of the costs associated with manufacturing them.[153]

For the other technologies, considering all sources of information and using the BOM approach, the agencies worked together intensively to determine component costs for each of the technologies and build up the costs accordingly. Where estimates differ between sources, we have used engineering judgment to arrive at what we believe to be the best cost estimate available today, and explained the basis for that exercise of judgment.

Once costs were determined, they were adjusted to ensure that they were all expressed in 2008 dollars using a ratio of gross domestic product (GDP) values for the associated calendar years,[154] and indirect costs were accounted for using the new approach developed by EPA and used in the 2012-2016 light-duty rule. NHTSA and EPA also reconsidered how costs should be adjusted by modifying or scaling content assumptions to account for differences across the range of vehicle sizes and functional requirements, and adjusted the associated material cost impacts to account for the revised content, although some of these adjustments may be different for each agency due to the different vehicle subclasses used in their respective models.

Regarding estimates for technology effectiveness, NHTSA and EPA used the estimates from the 2012-2016 light-duty rule as a baseline but adjusted them as appropriate, taking into account the unique requirement of the heavy-duty test cycles to test at curb weight plus half payload versus the light-duty requirement of curb plus 300 lb. The adjustments were made on an individual technology basis by assessing the specific impact of the added load on each technology when compared to the use of the technology on a light-duty vehicle. The agencies also considered other sources such as the 2010 NAS Report, recent CAFE compliance data, and confidential manufacturer estimates of technology effectiveness. NHTSA and EPA engineers reviewed effectiveness information from the multiple sources for each technology and ensured that such effectiveness estimates were based on technology hardware consistent with the BOM components used to estimate costs. Together, the agencies compared the multiple estimates and assessed their validity, taking care to ensure that common BOM definitions and other vehicle attributes such as performance and drivability were taken into account.

The agencies note that the effectiveness values estimated for the technologies may represent average values applied to the baseline fleet described earlier, and do not reflect the potentially-limitless spectrum of possible values that could result from adding the technology to different vehicles. For example, while the agencies have estimated an effectiveness of 0.5 percent for low friction lubricants, each vehicle could have a unique effectiveness estimate depending on the baseline vehicle's oil viscosity rating. Similarly, the reduction in rolling resistance (and thus the improvement in fuel efficiency and the reduction in CO2 emissions) due to the application of LRR tires depends not only on the unique characteristics of the tires originally on the vehicle, but on the unique characteristics of the tires being applied, characteristics which must be balanced between fuel efficiency, safety, and performance. Aerodynamic drag reduction is much the same—it can improve fuel efficiency and reduce CO2 emissions, but it is also highly dependent on vehicle-specific functional objectives. For purposes of this NPRM, NHTSA and EPA believe that employing average values for technology effectiveness estimates is an appropriate way of recognizing the potential variation in the specific benefits that individual manufacturers Start Printed Page 74234(and individual vehicles) might obtain from adding a fuel-saving technology. However, the agencies seek comment on whether additional levels of specificity beyond that already provided would improve the analysis for the final rules, and if so, how those levels of specificity should be analyzed.

The following section contains a detailed description of our assessment of vehicle technology cost and effectiveness estimates. The agencies note that the technology costs included in this NPRM take into account only those associated with the initial build of the vehicle. The agencies seek comment on the additional lifetime costs, if any, associated with the implementation of advanced technologies including maintenance and replacement costs. Based on comments, the agencies may decide to conduct additional analysis for the final rules regarding operating, maintenance and replacement costs.

(a) Engine Technologies

NHTSA and EPA have reviewed the engine technology estimates used in the 2012-2016 light-duty rule. In doing so NHTSA and EPA reconsidered all available sources and updated the estimates as appropriate. The section below describes both diesel and gasoline engine technologies considered for this proposal.

(i) Low Friction Lubricants

One of the most basic methods of reducing fuel consumption in both gasoline and diesel engines is the use of lower viscosity engine lubricants. More advanced multi-viscosity engine oils are available today with improved performance in a wider temperature band and with better lubricating properties. This can be accomplished by changes to the oil base stock (e.g., switching engine lubricants from a Group I base oils to lower-friction, lower viscosity Group III synthetic) and through changes to lubricant additive packages (e.g., friction modifiers and viscosity improvers). The use of 5W-30 motor oil is now widespread and auto manufacturers are introducing the use of even lower viscosity oils, such as 5W-20 and 0W-20, to improve cold-flow properties and reduce cold start friction. However, in some cases, changes to the crankshaft, rod and main bearings and changes to the mechanical tolerances of engine components may be required. In all cases, durability testing would be required to ensure that durability is not compromised. The shift to lower viscosity and lower friction lubricants will also improve the effectiveness of valvetrain technologies such as cylinder deactivation, which rely on a minimum oil temperature (viscosity) for operation.

Based on the 2012-2016 MY light-duty vehicle rule, and previously-received confidential manufacturer data, NHTSA and EPA estimated the effectiveness of low friction lubricants to be between 0 to 1 percent.

In the light-duty rule, the agencies estimated the cost of moving to low friction lubricants at $3 per vehicle (2007$). That estimate included a markup of 1.11 for a low complexity technology. For HD pickups and vans, we are using the same base estimate but have marked it up to 2008 dollars using the GDP price deflator and have used a markup of 1.17 for a low complexity technology to arrive at a value of $4 per vehicle. As in the light-duty rule, learning effects are not applied to costs for this technology and, as such, this estimate applies to all model years.[155 156]

(ii) Engine Friction Reduction

In addition to low friction lubricants, manufacturers can also reduce friction and improve fuel consumption by improving the design of both diesel and gasoline engine components and subsystems. Approximately 10 percent of the energy consumed by a vehicle is lost to friction, and just over half is due to frictional losses within the engine.[157] Examples include improvements in low-tension piston rings, piston skirt design, roller cam followers, improved crankshaft design and bearings, material coatings, material substitution, more optimal thermal management, and piston and cylinder surface treatments. Additionally, as computer-aided modeling software continues to improve, more opportunities for evolutionary friction reductions may become available.

All reciprocating and rotating components in the engine are potential candidates for friction reduction, and minute improvements in several components can add up to a measurable fuel efficiency improvement. The 2012-2016 light-duty final rule, the 2010 NAS Report, and NESCCAF and Energy and Environmental Analysis reports, as well as confidential manufacturer data, indicate a range of effectiveness for engine friction reduction to be between 1 to 3 percent. NHTSA and EPA continue to believe that this range is accurate.

Consistent with the 2012-2016 MY light-duty vehicle rule, the agencies estimate the cost of this technology at $14 per cylinder compliance cost (2008$), including the low complexity ICM markup value of 1.17. Learning impacts are not applied to the costs of this technology and, as such, this estimate applies to all model years. This cost is multiplied by the number of engine cylinders.

(iii) Coupled Cam Phasing

Valvetrains with coupled (or coordinated) cam phasing can modify the timing of both the inlet valves and the exhaust valves an equal amount by phasing the camshaft of an overhead valve engine.[158] For overhead valve engines, which have only one camshaft to actuate both inlet and exhaust valves, couple cam phasing is the only variable valve timing implementation option available and requires only one cam phaser.[159]

Based on the 2012-2016 light-duty final rule, previously-received confidential manufacturer data, and the NESCCAF report, NHTSA and EPA estimated the effectiveness of couple cam phasing to be between 1 and 4 percent. NHTSA and EPA reviewed this estimate for purposes of the NPRM, and continue to find it accurate.

In the 2012-2016 light-duty final rule, the agencies estimated a $41 cost per cam phaser not including any markup (2007$). NHTSA and EPA believe that this estimate remains accurate. Using the new indirect cost multiplier of 1.17, for a low complexity technology, the compliance cost per cam phaser would be $46 (2008$) in the 2014 model year. Time-based learning is applied to this Start Printed Page 74235technology. This technology was considered for gasoline engines only.

(iv) Cylinder Deactivation

In conventional spark-ignited engines throttling the airflow controls engine torque output. At partial loads, efficiency can be improved by using cylinder deactivation instead of throttling. Cylinder deactivation can improve engine efficiency by disabling or deactivating (usually) half of the cylinders when the load is less than half of the engine's total torque capability—the valves are kept closed, and no fuel is injected—as a result, the trapped air within the deactivated cylinders is simply compressed and expanded as an air spring, with reduced friction and heat losses. The active cylinders combust at almost double the load required if all of the cylinders were operating. Pumping losses are significantly reduced as long as the engine is operated in this “part-cylinder” mode.

Cylinder deactivation control strategy relies on setting maximum manifold absolute pressures or predicted torque within which it can deactivate the cylinders. Noise and vibration issues reduce the operating range to which cylinder deactivation is allowed, although manufacturers are exploring vehicle changes that enable increasing the amount of time that cylinder deactivation might be suitable. Some manufacturers may choose to adopt active engine mounts and/or active noise cancellations systems to address Noise Vibration and Harshness (NVH) concerns and to allow a greater operating range of activation. Cylinder deactivation is a technology keyed to more lightly loaded operation, and so may be a less likely technology choice for manufacturers designing for effectiveness in the loaded condition required for testing, and in the real world that involves frequent operation with heavy loads.

Cylinder deactivation has seen a recent resurgence thanks to better valvetrain designs and engine controls. General Motors and Chrysler Group have incorporated cylinder deactivation across a substantial portion of their V8-powered lineups.

Effectiveness improvements scale roughly with engine displacement-to-vehicle weight ratio: the higher displacement-to-weight vehicles, operating at lower relative loads for normal driving, have the potential to operate in part-cylinder mode more frequently.

NHTSA and EPA adjusted the 2012-2016 light-duty final rule estimates using updated power to weight ratings of heavy-duty trucks and confidential business information and confirmed a range of 3 to 4 percent for these vehicles, though as mentioned above there is uncertainty over how often this technology would be exercised on the test cycles, and a lower range may be warranted for HD vehicles.

NHTSA and EPA consider the costs for this technology to be identical to that for V8 engines on light-duty trucks. As such, the agencies have used the cost used in the 2012-2016 light-duty final rule. Using the new markup of 1.17 for a low complexity technology results in an estimate of $193 (2008$) in the 2014 model year. Time based learning is applied to this technology. This technology was considered for gasoline engines only.

(v) Stoichiometric Gasoline Direct Injection

SGDI engines inject fuel at high pressure directly into the combustion chamber (rather than the intake port in port fuel injection). SGDI requires changes to the injector design, an additional high pressure fuel pump, new fuel rails to handle the higher fuel pressures and changes to the cylinder head and piston crown design. Direct injection of the fuel into the cylinder improves cooling of the air/fuel charge within the cylinder, which allows for higher compression ratios and increased thermodynamic efficiency without the onset of combustion knock. Recent injector design advances, improved electronic engine management systems and the introduction of multiple injection events per cylinder firing cycle promote better mixing of the air and fuel, enhance combustion rates, increase residual exhaust gas tolerance and improve cold start emissions. SGDI engines achieve higher power density and match well with other technologies, such as boosting and variable valvetrain designs.

Several manufacturers have recently introduced vehicles with SGDI engines, including GM and Ford and have announced their plans to increase dramatically the number of SGDI engines in their portfolios.

The 2012-2016 light-duty final rule estimated the range of 1 to 2 percent for SGDI. NHTSA and EPA reviewed this estimate for purposes of the NPRM, and continue to find it accurate.

Consistent with the 2012-2016 light-duty final rule, NHTSA and EPA cost estimates for SGDI take into account the changes required to the engine hardware, engine electronic controls, ancillary and NVH mitigation systems. Through contacts with industry NVH suppliers, and manufacturer press releases, the agencies believe that the NVH treatments will be limited to the mitigation of fuel system noise, specifically from the injectors and the fuel lines. For this analysis, the agencies have estimated the costs at $395 (2008$) in the 2014 model year. Time based learning is applied to this technology. This technology was considered for gasoline engines only, as diesel engines already employ direct injection.

(b) Diesel Engine Technologies

Diesel engines have several characteristics that give them superior fuel efficiency compared to conventional gasoline, spark-ignited engines. Pumping losses are much lower due to lack of (or greatly reduced) throttling. The diesel combustion cycle operates at a higher compression ratio, with a very lean air/fuel mixture, and turbocharged light-duty diesels typically achieve much higher torque levels at lower engine speeds than equivalent-displacement naturally-aspirated gasoline engines. Additionally, diesel fuel has a higher energy content per gallon.[160] However, diesel fuel also has a higher carbon to hydrogen ratio, which increases the amount of CO2 emitted per gallon of fuel used by approximately 15 percent over a gallon of gasoline.

Based on confidential business information and the 2010 NAS Report, two major areas of diesel engine design will be improved during the 2014-2018 timeframe. These areas include aftertreatment improvements and a broad range of engine improvements.

(i) Aftertreatment Improvements

The HD diesel pickup and van segment has largely adopted the SCR type of aftertreatment system to comply with criteria pollutant emission standards. As the experience base for SCR expands over the next few years, many improvements in this aftertreatment system such as construction of the catalyst, thermal management, and reductant optimization will result in a significant reduction in the amount of fuel used in the process. This technology was not considered in the 2012-2016 light-duty final rule. Based on confidential business information, EPA and NHTSA estimate the reduction in CO2 as a result of these improvements at 3 to 5 percent.

The agencies have estimated the cost of this technology at $25 for each percentage improvement in fuel consumption. This estimate is based on Start Printed Page 74236the agencies' belief that this technology is, in fact, a very cost effective approach to improving fuel consumption. As such, $25 per percent improvement is considered a reasonable cost. This cost would cover the engineering and test cell related costs necessary to develop and implement the improved control strategies that would allow for the improvements in fuel consumption. Importantly, the engineering work involved would be expected to result in cost savings to the aftertreatment and control hardware (lower platinum group metal loadings, lower reductant dosing rates, etc.). Those savings are considered to be included in the $25 per percent estimate described here. Given the 4 percent average expected improvement in fuel consumption results in an estimated cost of $110 (2008$) for a 2014 model year truck or van. This estimate includes a low complexity ICM of 1.17 and time based learning from 2012 forward.

(ii) Engine Improvements

Diesel engines in the HD pickup and van segment are expected to have several improvements in their base design in the 2014-2018 timeframe. These improvements include items such as improved combustion management, optimal turbocharger design, and improved thermal management. This technology was not considered in the 2012-2016 light-duty final rule. Based on confidential business information, EPA and NHTSA estimate the reduction in CO2 as a result of these improvements at 4 to 6 percent.

The cost for this technology includes costs associated with low temperature exhaust gas recirculation, improved turbochargers and improvements to other systems and components. These costs are considered collectively in our costing analysis and termed “diesel engine improvements.” The agencies have estimated the cost of diesel engine improvements at $147 based on the cost estimates for several individual technologies. Specifically, the direct manufacturing costs we have estimated are: improved cylinder head, $9; turbo efficiency improvements, $16; EGR cooler improvements, $3; higher pressure fuel rail, $10; improved fuel injectors, $13; improved pistons, $2; and reduced valve train friction, $94. All values are in 2008 dollars and are applicable in the 2014MY. Applying a low complexity ICM of 1.17 results in a cost of $172 (2008$) applicable in the 2014MY. We consider time based learning to be appropriate for these technologies.

(c) Transmission Technologies

NHTSA and EPA have also reviewed the transmission technology estimates used in the 2012-2016 light-duty final rule. In doing so, NHTSA and EPA considered or reconsidered all available sources and updated the estimates as appropriate. The section below describes each of the transmission technologies considered for this proposal.

(i) Improved Automatic Transmission Control (Aggressive Shift Logic and Early Torque Converter Lockup)

Calibrating the transmission shift schedule to upshift earlier and quicker, and to lock-up or partially lock-up the torque converter under a broader range of operating conditions can reduce fuel consumption and CO2 emissions. However, this operation can result in a perceptible degradation in NVH. The degree to which NVH can be degraded before it becomes noticeable to the driver is strongly influenced by characteristics of the vehicle, and although it is somewhat subjective, it always places a limit on how much fuel consumption can be improved by transmission control changes. Given that the Aggressive Shift Logic and Early Torque Converter Lockup are best optimized simultaneously due to the fact that adding both of them primarily requires only minor modifications to the transmission or calibration software, these two technologies are combined in the modeling. We consider these technologies to be present in the baseline, since 6-speed automatic transmissions are installed in the majority of Class 2b and 3 trucks in the 2010 model year timeframe.

(ii) Automatic 6- and 8-Speed Transmissions

Manufacturers can also choose to replace 4- 5- and 6-speed automatic transmissions with 8-speed automatic transmissions. Additional ratios allow for further optimization of engine operation over a wider range of conditions, but this is subject to diminishing returns as the number of speeds increases. As additional planetary gear sets are added (which may be necessary in some cases to achieve the higher number of ratios), additional weight and friction are introduced. Also, the additional shifting of such a transmission can be perceived as bothersome to some consumers, so manufacturers need to develop strategies for smooth shifts. Some manufacturers are replacing 4- and 5-speed automatics with 6-speed automatics already, and 7- and 8-speed automatics have entered production in light-duty vehicles, albeit in lower-volume applications in luxury and performance oriented cars.

As discussed in the light-duty final GHG rule, confidential manufacturer data projected that 6-speed transmissions could incrementally reduce fuel consumption by 0 to 5 percent from a 4-speed automatic transmission, while an 8-speed transmission could incrementally reduce fuel consumption by up to 6 percent from a 4-speed automatic transmission. GM has publicly claimed a fuel economy improvement of up to 4 percent for its new 6-speed automatic transmissions.[161]

NHTSA and EPA reviewed and revised these effectiveness estimates based on actual usage statistics and testing methods for these vehicles along with confidential business information. When combined with improved automatic transmission control, the agencies estimate the effectiveness for a conversion from a 4 to a 6-speed transmission to be 5.3% and a conversion from a 6 to 8-speed transmission to be 1.7%. While 8-speed transmissions were not considered in the 2012-2016 light-duty final rule, they are considered as a technology of choice for this analysis in that manufacturers are expected to upgrade the 6-speed automatic transmissions being implemented today with 8-speed automatic transmissions in the 2014-2018 timeframe. For this proposal, we are estimating the cost of an 8-speed automatic transmission at $231 (2008$) relative to a 6-speed automatic transmission in the 2014 model year. This estimate is based from the 2010 NAS Report and we have applied a low complexity ICM of 1.17 and time based learning. This technology applies to both gasoline and diesel trucks and vans.

(d) Electrification/Accessory Technologies

(i) Electrical Power Steering or Electrohydraulic Power Steering

Electric power steering (EPS) or Electrohydraulic power steering (EHPS) provides a potential reduction in CO2 emissions and fuel consumption over hydraulic power steering because of reduced overall accessory loads. This eliminates the parasitic losses Start Printed Page 74237associated with belt-driven power steering pumps which consistently draw load from the engine to pump hydraulic fluid through the steering actuation systems even when the wheels are not being turned. EPS is an enabler for all vehicle hybridization technologies since it provides power steering when the engine is off. EPS may be implemented on most vehicles with a standard 12V system. Some heavier vehicles may require a higher voltage system which may add cost and complexity.

The 2012-2016 light-duty final rule estimated a 1 to 2 percent effectiveness based on the 2002 NAS report for light-duty vehicle technologies, a Sierra Research report, and confidential manufacturer data. NHTSA and EPA reviewed these effectiveness estimates and found them to be accurate, thus they have been retained for purposes of this NPRM.

NHTSA and EPA adjusted the EPS cost for the current rulemaking based on a review of the specification of the system. Adjustments were made to include potentially higher voltage or heavier duty system operation for HD pickups and vans. Accordingly, higher costs were estimated for systems with higher capability. After accounting for the differences in system capability and applying the ICM markup of low complexity technology of 1.17, the estimated costs for this proposal are $108 for a MY 2014 truck or van (2008$). As EPS systems are in widespread usage today, time-based learning is deemed applicable. EHPS systems are considered to be of equal cost and both are considered applicable to gasoline and diesel engines.

(ii) Improved Accessories

The accessories on an engine, including the alternator, coolant and oil pumps are traditionally mechanically-driven. A reduction in CO2 emissions and fuel consumption can be realized by driving them electrically, and only when needed (“on-demand”).

Electric water pumps and electric fans can provide better control of engine cooling. For example, coolant flow from an electric water pump can be reduced and the radiator fan can be shut off during engine warm-up or cold ambient temperature conditions which will reduce warm-up time, reduce warm-up fuel enrichment, and reduce parasitic losses.

Indirect benefit may be obtained by reducing the flow from the water pump electrically during the engine warm-up period, allowing the engine to heat more rapidly and thereby reducing the fuel enrichment needed during cold starting of the engine. Further benefit may be obtained when electrification is combined with an improved, higher efficiency engine alternator. Intelligent cooling can more easily be applied to vehicles that do not typically carry heavy payloads, so larger vehicles with towing capacity present a challenge, as these vehicles have high cooling fan loads.[162]

The agencies considered whether to include electric oil pump technology for the rulemaking. Because it is necessary to operate the oil pump any time the engine is running, electric oil pump technology has insignificant effect on efficiency. Therefore, the agencies decided to not include electric oil pump technology for this proposal.

NHTSA and EPA jointly reviewed the estimates of 1 to 2 percent effectiveness estimates used in the 2012-2016 light-duty final rule and found them to be accurate for Improved Electrical Accessories. Consistent with the 2012-2016 light-duty final rule, the agencies have estimated the cost of this technology at $88 (2008$) including a low complexity ICM of 1.17. This cost is applicable in the 2014 model year. Improved accessory systems are in production currently and thus time-based learning is applied. This technology was considered for diesel trucks and vans only.

(e) Vehicle Technologies

(i) Mass Reduction

Reducing a vehicle's mass, or down-weighting the vehicle, decreases fuel consumption by reducing the energy demand needed to overcome forces resisting motion, and rolling resistance. Manufacturers employ a systematic approach to mass reduction, where the net mass reduction is the addition of a direct component or system mass reduction plus the additional mass reduction taken from indirect ancillary systems and components, as a result of full vehicle optimization, effectively compounding or obtaining a secondary mass reduction from a primary mass reduction. For example, use of a smaller, lighter engine with lower torque-output subsequently allows the use of a smaller, lighter-weight transmission and drive line components. Likewise, the compounded weight reductions of the body, engine and drivetrain reduce stresses on the suspension components, steering components, wheels, tires and brakes, allowing further reductions in the mass of these subsystems. The reductions in unsprung masses such as brakes, control arms, wheels and tires further reduce stresses in the suspension mounting points. This produces a compounding effect of mass reductions.

Estimates of the synergistic effects of mass reduction and the compounding effect that occurs along with it can vary significantly from one report to another. For example, in discussing its estimate, an Auto-Steel Partnership report states that “These secondary mass changes can be considerable—estimated at an additional 0.7 to 1.8 times the initial mass change.”§[163] This means for each one pound reduction in a primary component, up to 1.8 pounds can be reduced from other structures in the vehicle (i.e., a 180 percent factor). The report also discusses that a primary variable in the realized secondary weight reduction is whether or not the powertrain components can be included in the mass reduction effort, with the lower end estimates being applicable when powertrain elements are unavailable for mass reduction. However, another report by the Aluminum Association, which primarily focuses on the use of aluminum as an alternative material for steel, estimated a factor of 64 percent for secondary mass reduction even though some powertrain elements were considered in the analysis.[164] That report also notes that typical values for this factor vary from 50 to 100 percent. Although there is a wide variation in stated estimates, synergistic mass reductions do exist, and the effects result in tangible mass reductions. Mass reductions in a single vehicle component, for example a door side impact/intrusion system, may actually result in a significantly higher weight savings in the total vehicle, depending on how well the manufacturer integrates the modification into the overall vehicle design. Accordingly, care must be taken when reviewing reports on weight reduction methods and practices to ascertain if compounding effects have been considered or not.

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Mass reduction is broadly applicable across all vehicle subsystems including the engine, exhaust system, transmission, chassis, suspension, brakes, body, closure panels, glazing, seats and other interior components, engine cooling systems and HVAC systems. It is estimated that up to 1.25 kilograms of secondary weight savings can be achieved for every kilogram of weight saved on a vehicle when all subsystems are redesigned to take into account the initial primary weight savings.[165 166]

Mass reduction can be accomplished by proven methods such as:

  • Smart Design: Computer aided engineering (CAE) tools can be used to better optimize load paths within structures by reducing stresses and bending moments applied to structures. This allows better optimization of the sectional thicknesses of structural components to reduce mass while maintaining or improving the function of the component. Smart designs also integrate separate parts in a manner that reduces mass by combining functions or the reduced use of separate fasteners. In addition, some “body on frame” vehicles are redesigned with a lighter “unibody” construction.
  • Material Substitution: Substitution of lower density and/or higher strength materials into a design in a manner that preserves or improves the function of the component. This includes substitution of high-strength steels, aluminum, magnesium or composite materials for components currently fabricated from mild steel.
  • Reduced Powertrain Requirements: Reducing vehicle weight sufficiently allows for the use of a smaller, lighter and more efficient engine while maintaining or increasing performance. Approximately half of the reduction is due to these reduced powertrain output requirements from reduced engine power output and/or displacement, changes to transmission and final drive gear ratios. The subsequent reduced rotating mass (e.g., transmission, driveshafts/halfshafts, wheels and tires) via weight and/or size reduction of components are made possible by reduced torque output requirements.
  • Automotive companies have largely used weight savings in some vehicle subsystems to offset or mitigate weight gains in other subsystems from increased feature content (sound insulation, entertainment systems, improved climate control, panoramic roof, etc.).
  • Lightweight designs have also been used to improve vehicle performance parameters by increased acceleration performance or superior vehicle handling and braking.

Many manufacturers have already announced proposed future products plans reducing the weight of a vehicle body through the use of high strength steel body-in-white, composite body panels, magnesium alloy front and rear energy absorbing structures reducing vehicle weight sufficiently to allow a smaller, lighter and more efficient engine. Nissan will be reducing average vehicle curb weight by 15% by 2015.[167] Ford has identified weight reductions of 250 to 750 lb per vehicle as part of its implementation of known technology within its sustainability strategy between 2011 and 2020.[168] Mazda plans to reduce vehicle weight by 220 pounds per vehicle or more as models are redesigned.[169, 170] Ducker International estimates that the average curb weight of light-duty vehicle fleet will decrease approximately 2.8% from 2009 to 2015 and approximately 6.5% from 2009 to 2020 via changes in automotive materials and increased change-over from previously used body-on-frame automobile and light-truck designs to newer unibody designs.167 While the opportunity for mass reductions available to the light-duty fleet may not in all cases be applied directly to the heavy-duty fleet due to the different designs for the expected duty cycles of a “work” vehicle, mass reductions are still available particularly to areas unrelated to the components necessary for the work vehicle aspects.

Due to the payload and towing requirements of these heavy-duty vehicles, engine downsizing was not considered in the estimates for CO2 reduction in the area of mass reduction/material substitution. NHTSA and EPA estimate that a 3 percent mass reduction with no engine downsizing results in a 1 percent reduction in fuel consumption. In addition, a 5 and 10 percent mass reduction with no engine downsizing result in an estimated CO2 reduction of 1.6 and 3.2 percent respectively. These effectiveness values are 50% of the 2012-2016 light-duty final rule values due to the elimination of engine downsizing for this class of vehicle.

Consistent with the 2012-2016 light-duty final rule, the agencies have estimated the cost of mass reduction at $1.32 per pound (2008$). For this analysis, the agencies are estimating a 5% mass reduction or, given the baseline weight of current trucks and vans, are estimating costs of $462, $544, $513, and $576 for Class 2b gasoline, 2b diesel, 3 gasoline, 3 diesel trucks and vans, respectively. All values are in 2008 dollars, are applicable in the 2014 model year and include a low complexity ICM of 1.17. Time based learning is considered applicable to mass reduction technologies.

The agencies have recently completed work on an Interim Joint Technical Assessment Report that considers light-duty GHG and fuel economy standards for the years 2017 through 2025.[171] In that report, the agencies have used updated cost estimates for mass reduction which were not available in time for use in this analysis but could be used in the final analysis. The agencies request comment on which mass reduction costs—those used in this draft analysis or those used in the Joint Technical Assessment Report—would be most appropriate for Class 2b & 3 trucks and vans along with supporting information.

(ii) Low Rolling Resistance Tires

Tire rolling resistance is the frictional loss associated mainly with the energy dissipated in the deformation of the tires under load and thus influences fuel efficiency and CO2 emissions. Other tire design characteristics (e.g., materials, construction, and tread design) influence durability, traction (both wet and dry grip), vehicle handling, and ride comfort in addition to rolling resistance. A typical LRR tire's attributes would include: increased tire inflation Start Printed Page 74239pressure, material changes, and tire construction with less hysteresis, geometry changes (e.g., reduced aspect ratios), and reduction in sidewall and tread deflection. These changes would generally be accompanied with additional changes to suspension tuning and/or suspension design.

EPA and NHTSA estimated a 1 to 2 percent increase in effectiveness with a 10 percent reduction in rolling resistance, which was based on the 2010 NAS Report findings and consistent with the 2012-2016 light-duty final rule.

Based on the 2012-2016 light-duty final rule and the 2010 NAS Report, the agencies have estimated the cost for LRR tires to be $6 per Class 2b truck or van, and $9 per Class 3 truck or van.[172] The higher cost for the Class 3 trucks and vans is due to the predominant use of dual rear tires and, thus, 6 tires per truck. Due to the commodity-based nature of this technology, cost learning is not applied. This technology is considered applicable to both gasoline and diesel.

(iii) Aerodynamic Drag Reduction

Many factors affect a vehicle's aerodynamic drag and the resulting power required to move it through the air. While these factors change with air density and the square and cube of vehicle speed, respectively, the overall drag effect is determined by the product of its frontal area and drag coefficient, Cd. Reductions in these quantities can therefore reduce fuel consumption and CO2 emissions. Although frontal areas tend to be relatively similar within a vehicle class (mostly due to market-competitive size requirements), significant variations in drag coefficient can be observed. Significant changes to a vehicle's aerodynamic performance may need to be implemented during a redesign (e.g., changes in vehicle shape). However, shorter-term aerodynamic reductions, with a somewhat lower effectiveness, may be achieved through the use of revised exterior components (typically at a model refresh in mid-cycle) and add-on devices that currently being applied. The latter list would include revised front and rear fascias, modified front air dams and rear valances, addition of rear deck lips and underbody panels, and lower aerodynamic drag exterior mirrors.

The 2012-2016 light-duty final rule estimated that a fleet average of 10 to 20 percent total aerodynamic drag reduction is attainable which equates to incremental reductions in fuel consumption and CO2 emissions of 2 to 3 percent for both cars and trucks. These numbers are generally supported by confidential manufacturer data and public technical literature. For the heavy-duty truck category, a 5 to 10 percent total aerodynamic drag reduction was considered due to the different structure and use of these vehicles equating to incremental reductions in fuel consumption and CO2 emissions of 1 to 2 percent.

Consistent with the 2012-2016 light-duty final rule, the agencies have estimated the cost for this technology at $54 (2008$) including a low complexity ICM of 1.17. This cost is applicable in the 2014 model year to both gasoline and diesel trucks and vans.

(3) What are the projected technology packages' effectiveness and cost?

The assessment of the proposed technology effectiveness was developed through the use of the EPA Lumped Parameter model developed for the light-duty rule. Many of the technologies were common with the light-duty assessment but the effectiveness of individual technologies was appropriately adjusted to match the expected effectiveness when implemented in a heavy-duty application. The model then uses the individual technology effectiveness levels but then takes into account technology synergies. The model is also designed to prevent double counting from technologies that may directly or indirectly impact the same physical attribute (e.g., pumping loss reductions).

To achieve the levels of the proposed standards for gasoline and diesel powered heavy-duty vehicles, the technology packages were determined to generally require the technologies previously discussed respective to unique gasoline and diesel technologies. Although some of the technologies may already be implemented in a portion of heavy-duty vehicles, none of the technologies discussed are considered ubiquitous in the heavy-duty fleet. Also, as would be expected, the available test data shows that some vehicle models will not need the full complement of available technologies to achieve the proposed standards. Furthermore, many technologies can be further improved (e.g., aerodynamic improvements) from today's best levels, and so allow for compliance without needing to apply a technology that a manufacturer might deem less desirable.

Technology costs for HD pickup trucks and vans are shown in Table III-11.

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(4) Reasonableness of the Proposed Standards

The proposed standards are based on the application of the control technologies described in this section. These technologies are available within the lead time provided, as discussed in draft RIA Chapter 2.3. These controls are estimated to add costs of approximately $1,249 to $1,592 for MY 2018 heavy-duty pickups and vans. Reductions associated with these costs and technologies are considerable, estimated at a 12 percent reduction of CO2 eq emissions from the MY 2010 baseline for gasoline engine-equipped vehicles and 17 percent for diesel engine equipped vehicles, estimated to result in reductions of 21 MMT of CO2 eq emissions over the lifetimes of 2014 through 2018 MY vehicles.[173] The reductions are cost effective, estimated at $100 per ton of CO2 eq removed in 2030.[174] This cost is consistent with the light-duty rule which was estimated at $100 per ton of CO2 eq removed in 2020 excluding fuel savings. Moreover, taking into account the fuel savings associated with the program, the cost becomes −$200 per ton of CO2 eq in 2030. The cost of controls is fully recovered due to the associated fuel savings, with a payback period within the fifth and sixth year of ownership, as shown in Table VIII-6 below. Given the large, cost effective emission reductions based on use of feasible technologies which are available in the lead time provided, plus the lack of adverse impacts on vehicle safety or utility, EPA and NHTSA regard these proposed standards as appropriate and consistent with our respective statutory authorities under CAA section 202(a) and NHTSA's EISA authority under 49 U.S.C. 32902(k)(2).

C. Class 2b-8 Vocational Vehicles

Vocational vehicles cover a wide variety of applications which influence both the body style and usage patterns. They also are built using a complex process, which includes additional parties such as body builders. These factors have led the agencies to propose a vehicle standard for vocational vehicles for the first phase of the program that relies on less extensive addition of technology as well as focusing on the chassis manufacturer as the manufacturer subject to the standard. We believe that future rulemakings will consider increased stringency and possibly more application-specific standards. The agencies are proposing standards for the diesel and gasoline engines used in vocational vehicles, similar to those discussed above for Class 7 and 8 tractors.

(1) What technologies did the agencies consider to reduce the CO2 emissions and fuel consumption of vocational vehicles?

Similar to the approach taken with tractors, the agencies evaluated aerodynamic, tire, idle reduction, weight reduction, hybrid powertrain, and engine technologies and their impact on reducing fuel consumption and GHG emissions. The engines used in vocational vehicles include both gasoline and diesel engines, thus, each type is discussed separately below. As explained in Section II.D.1.b, the proposed regulatory structure for heavy-duty engines separates the compression ignition (or “diesel”) engines into three regulatory subcategories—light heavy, medium heavy, and heavy heavy diesel Start Printed Page 74241engines—while spark ignition (or “gasoline”) engines are a single regulatory subcategory. Therefore, the subsequent discussion will assess each type of engine separately.

(a) Vehicle Technologies

Vocational vehicles typically travel fewer miles than combination tractors. They also tend to be used in more urban locations (with consequent stop and start drive cycles). Therefore the average speed of vocational vehicles is significantly lower than tractors. This has a significant effect on the types of technologies that are appropriate to consider for reducing CO2 emissions and fuel consumption.

The agencies considered the type of technologies for vocational vehicles based on the energy losses of a typical vocational vehicle. The technologies are similar to the ones considered for tractors. Argonne National Lab conducted an energy audit using simulation tools to evaluate the energy losses of vocational vehicles, such as a Class 6 pickup and delivery truck. Argonne found that 74 percent of the energy losses are attributed to the engine, 13 percent to tires, 9 percent to aerodynamics, two percent to transmission losses, and the remaining four percent of losses to axles and accessories for a medium-duty truck traveling at 30 mph.[175]

Low Rolling Resistance Tires: Tires are the second largest contributor to energy losses of vocational vehicles, as found in the energy audit conducted by Argonne National Lab (as just mentioned). The range of rolling resistance of tires used on vocational vehicles today is large. This is in part due to the fact that the competitive pressure to improve rolling resistance of vocational vehicle tires has been less than that found in the line haul tire market. In addition, the drive cycles typical for these applications often lead truck buyers to value tire traction and durability more heavily than rolling resistance. Therefore, the agencies concluded that a regulatory program that seeks to optimize tire rolling resistance in addition to traction and durability can bring about fuel consumption and CO2 emission reductions from this segment. The 2010 NAS report states that rolling resistance impact on fuel consumption reduces with mass of the vehicle and with drive cycles with more frequent starts and stops. The report found that the fuel consumption reduction opportunity for reduced rolling resistance ranged between one and three percent in the 2010 through 2020 timeframe.[176] The agencies estimate that average rolling resistance from tires in 2010 model year can be reduced by 10 percent by 2014 model year based on the tire development achievements over the last several years in the line haul truck market which would lead to a 2 percent reduction in fuel consumption based on GEM.

Aerodynamics: The Argonne National lab work shows that aerodynamics have less of an impact on vocational vehicle energy losses than do engines or tires. In addition, the aerodynamic performance of a complete vehicle is significantly influenced by the body of the truck. The agencies are not proposing to regulate body builders in this phase of regulations for the reasons discussed in Section II. Therefore, we are not basing any of the proposed standards for vocational vehicles on aerodynamic improvements. Nor would aerodynamic performance be input into GEM to demonstrate compliance.

Weight Reduction: NHTSA and EPA are also not basing any of the proposed standards on use of vehicle weight reduction. Thus, vehicle mass reductions would not be input into GEM. The vocational vehicle models are not designed to be application-specific. Therefore weight reductions are difficult to quantify.

Drivetrain: Optimization of vehicle gearing to engine performance through selection of transmission gear ratios, final drive gear ratios and tire size can play a significant role in reducing fuel consumption and GHGs. Optimization of gear selection versus vehicle and engine speed accomplished through driver training or automated transmission gear selection can provide additional reductions. The 2010 NAS report found that the opportunities to reduce fuel consumption in heavy-duty vehicles due to transmission and driveline technologies in the 2015 timeframe ranged between 2 and 8 percent.[177] Initially, the agencies considered reflecting transmission choices and technology in our standard setting process for both tractors and vocational vehicles (see previous discussion above on automated transmissions for tractors). We have however decided not to do so for the following reasons.

The primary factors that determine optimum gear selection are vehicle weight, vehicle aerodynamics, vehicle speed, and engine performance typically considered on a two dimensional map of engine speed and torque. For a given power demand (determined by speed, aerodynamics and vehicle mass) an optimum transmission and gearing setup will keep the engine power delivery operating at the best speed and torque points for highest engine efficiency. Since power delivery from the engine is the product of speed and torque a wide range of torque and speed points can be found that deliver adequate power, but only a smaller subset will provide power with peak efficiency. Said more generally, the design goal is for the transmission to deliver the needed power to the vehicle while maintaining engine operation within the engine's “sweet spot” for most efficient operation. Absent information about vehicle mass and aerodynamics (which determines road load at highway speeds) it is not possible to optimize the selection of gear ratios for lowest fuel consumption. Truck and chassis manufacturers today offer a wide range of tire sizes, final gear ratios and transmission choices so that final bodybuilders can select an optimal combination given the finished vehicle weight, general aerodynamic characteristics and expected average speed. In order to set fuel efficiency and GHG standards that would reflect these optimizations, the agencies would need to regulate a wide range of small entities that are final bodybuilders, would need to set a large number of uniquely different standards to reflect the specific weight and aerodynamic differences and finally would need test procedures to evaluate these differences that would not themselves be excessively burdensome. Finally, the agencies would need the underlying data regarding effectively all of the vocational trucks produced today in order to determine the appropriate standards. Because the market is already motivated to reach these optimizations themselves today, because we have insufficient data to determine appropriate standards, and finally, because we believe the testing burden would be unjustifiably high, we are not proposing to reflect transmission and gear ratio optimization in our GEM model or in our standard setting.

We are broadly seeking comment on our reasons for not reflecting these technology choices including recommendations for ways that the agencies could effectively reflect transmission related improvements. The agencies welcome comment on transmission and driveline technologies Start Printed Page 74242specific to the vocational vehicle market that can achieve fuel consumption and GHG emissions reductions.

Idle Reduction: Episodic idling by vocational vehicles occurs during the workday, unlike the overnight idling of combination tractors. Vocational vehicle idling can be divided into two typical types. The first type is idling while waiting—such as during a pickup or delivery. This type of idling can be reduced through automatic engine shut-offs. The second type of idling is to accomplish PTO operation, such as compacting garbage or operating a bucket. The agencies have found only one study that quantifies the emissions due to idling conducted by Argonne National Lab based on 2002 VIUS data.[178] EPA conducted a work assignment to assist in characterizing PTO operations. The study of a utility truck used in two different environments (rural and urban) and a refuse hauler found that the PTO operated on average 28 percent of time relative to the total time spent driving and idling. The use of hybrid powertrains to reduce idling is discussed below.

Hybrid Powertrains: Several types of vocational vehicles are well suited for hybrid powertrains. Vehicles such as utility or bucket trucks, delivery vehicles, refuse haulers, and buses have operational usage patterns with either a significant amount of stop-and-go activity or spend a large portion of their operating hours idling the main engine to operate a PTO unit. The industry is currently developing three types of hybrid powertrain systems—hydraulic, electric, and plug-in electric. The hybrids developed to date have seen fuel consumption and CO2 emissions reductions between 20 and 50 percent in the field. However, there are still some key issues that are restricting the penetration of hybrids, including overall system cost, battery technology, and lack of cost-effective electrified accessories. The agencies are proposing to include hybrid powertrains as a technology to meet the vocational vehicle standard, as described in Section IV. However, the agencies are not proposing a vocational vehicle standard predicated on using a specific penetration of hybrids. We have not predicated the standards based on the use of hybrids reflecting the still nascent level of technology development and the very small fraction of vehicle sales they would be expected to account for in this timeframe—on the order of only a percent or two. Were we to overestimate the number of hybrids that could be produced, we would set a standard that is not feasible. We believe that it is more appropriate given the status of technology development and our high hopes for future advancements in hybrid technologies to encourage their production through incentives. The agencies welcome comments on this approach.

(b) Gasoline Engine Technologies

The gasoline (or spark ignited) engines certified and sold as loose engines into the heavy-duty truck market are typically large V8 and V10 engines produced by General Motors and Ford. The basic engine architecture of these engines is the same as the versions used in the heavy-duty pickup trucks and vans. Therefore, the technologies analyzed by the agencies mirror the gasoline engine technologies used in the heavy-duty pickup truck analysis in Section III.B above.

Building on the technical analysis underlying the 2012-2016 MY light-duty vehicle rule, the agencies took a fresh look at technology effectiveness values for purposes of this proposal using a starting point the estimates from that rule. The agencies then considered the impact of test procedures (such as higher test weight of HD pickup trucks and vans) on the effectiveness estimates. The agencies also considered other sources such as the 2010 NAS Report, recent CAFE compliance data, and confidential manufacturer estimates of technology effectiveness. NHTSA and EPA engineers reviewed effectiveness information from the multiple sources for each technology and ensured that such effectiveness estimates were based on technology hardware consistent with the BOM components used to estimate costs.

The agencies note that the effectiveness values estimated for the technologies may represent average values, and do not reflect the potentially-limitless spectrum of possible values that could result from adding the technology to different vehicles. For example, while the agencies have estimated an effectiveness of 0.5 percent for low friction lubricants, each vehicle could have a unique effectiveness estimate depending on the baseline vehicle's oil viscosity rating. For purposes of this NPRM, NHTSA and EPA believe that employing average values for technology effectiveness estimates is an appropriate way of recognizing the potential variation in the specific benefits that individual manufacturers (and individual engines) might obtain from adding a fuel-saving technology. However, the agencies seek comment on whether additional levels of specificity beyond that already provided would improve the analysis for the final rules, and if so, how those levels of specificity should be analyzed.

Baseline Engine: Similar to the gasoline engine used as the baseline in the light-duty GHG rule, the agencies assumed the baseline engine in this segment to be a naturally aspirated, overhead valve V8 engine. The following discussion of effectiveness is generally in comparison to 2010 baseline engine performance.

The technologies the agencies considered include the following:

Engine Friction Reduction: In addition to low friction lubricants, manufacturers can also reduce friction and improve fuel consumption by improving the design of engine components and subsystems. Examples include improvements in low-tension piston rings, piston skirt design, roller cam followers, improved crankshaft design and bearings, material coatings, material substitution, more optimal thermal management, and piston and cylinder surface treatments. The 2010 NAS, NESCCAF [179] and EEA [180] reports as well as confidential manufacturer data used in the light-duty vehicle rulemaking suggested a range of effectiveness for engine friction reduction to be between 1 to 3 percent. NHTSA and EPA continue to believe that this range is accurate.

Coupled Cam Phasing: Valvetrains with coupled (or coordinated) cam phasing can modify the timing of both the inlet valves and the exhaust valves an equal amount by phasing the camshaft of a single overhead cam engine or an overhead valve engine. Based on the 2012-2016 MY light-duty vehicle rule, previously-received confidential manufacturer data, and the NESCCAF report, NHTSA and EPA estimated the effectiveness of couple cam phasing CCP to be between 1 and 4 percent. NHTSA and EPA reviewed this estimate for purposes of the NPRM, and continue to find it accurate.

Cylinder Deactivation: In conventional spark-ignited engines throttling the airflow controls engine torque output. At partial loads, efficiency can be improved by using cylinder deactivation instead of throttling. Cylinder deactivation can improve engine efficiency by disabling or deactivating (usually) half of the Start Printed Page 74243cylinders when the load is less than half of the engine's total torque capability—the valves are kept closed, and no fuel is injected—as a result, the trapped air within the deactivated cylinders is simply compressed and expanded as an air spring, with reduced friction and heat losses. The active cylinders combust at almost double the load required if all of the cylinders were operating. Pumping losses are significantly reduced as long as the engine is operated in this “part cylinder” mode. Effectiveness improvements scale roughly with engine displacement-to-vehicle weight ratio—the higher displacement-to-weight vehicles, operating at lower relative loads for normal driving, have the potential to operate in part-cylinder mode more frequently. Therefore, the agencies reduced the effectiveness assumed from this technology for trucks because of the lower displacement-to-weight ratio relative to light-duty vehicles. NHTSA and EPA adjusted the 2010 light-duty vehicle final rule estimates using updated power to weight ratings of heavy-duty trucks and confidential business information and confirmed a range of 3 to 4 percent for these vehicles.

Stoichiometric gasoline direct injection: SGDI (also known as spark-ignition direct injection engines) inject fuel at high pressure directly into the combustion chamber (rather than the intake port in port fuel injection). Direct injection of the fuel into the cylinder improves cooling of the air/fuel charge within the cylinder, which allows for higher compression ratios and increased thermodynamic efficiency without the onset of combustion knock. Recent injector design advances, improved electronic engine management systems and the introduction of multiple injection events per cylinder firing cycle promote better mixing of the air and fuel, enhance combustion rates, increase residual exhaust gas tolerance and improve cold start emissions. SGDI engines achieve higher power density and match well with other technologies, such as boosting and variable valvetrain designs. The 2012-2016 MY light-duty vehicle final rule estimated the effectiveness of SGDI to be between 2 and 3 percent. NHTSA and EPA revised these estimated accounting for the use and testing methods for these vehicles along with confidential business information estimates received from manufacturers while developing the proposal. Based on these revisions, NHTSA and EPA estimate the range of 1 to 2 percent for SGDI.

(c) Diesel Engine Technologies

Different types of diesel engines are used in vocational vehicles, depending on the application. They fall into the categories of Light, Medium, and Heavy Heavy-duty Diesel engines. The Light Heavy-duty Diesel engines typically range between 4.7 and 6.7 liters displacement. The Medium Heavy-duty Diesel engines typically have some overlap in displacement with the Light Heavy-duty Diesel engines and range between 6.7 and 9.3 liters. The Heavy Heavy-duty Diesel engines typically are represented by engines between 10.8 and 16 liters.

Baseline Engine: There are three baseline diesel engines, a Light, Medium, and a Heavy Heavy-duty Diesel engine. The agencies developed the baseline diesel engine as a 2010 model year engine with an aftertreatment system which meets EPA's 0.2 grams of NOX/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 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.C.2.(c)(i) below. The following discussion of effectiveness is generally in comparison to 2010 baseline engine performance, and is in reference to performance in terms of the Heavy-duty FTP that would be used for compliance for these engine standards. This is in comparison to the steady state SET procedure that would be used for compliance purposes for the engines used in Class 7 and 8 tractors. See Section II.B.2.(i) above.

Turbochargers: Improved efficiency of a turbocharger compressor or turbine could reduce fuel consumption by approximately 1 to 2 percent over today's variable geometry turbochargers in the market today. 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.

Low Temperature Exhaust Gas Recirculation: Most LHDD, MHDD, and HHDD 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 NOX. Low-temperature EGR uses a larger or secondary EGR cooler to achieve lower intake charge temperatures, which tend to further reduce NOX formation. If the NOX requirement is unchanged, low-temperature EGR can allow changes such as more advanced injection timing that will increase engine efficiency slightly more than one percent. Because low-temperature EGR reduces the engine's exhaust temperature, it may not be compatible with exhaust energy recovery systems such as turbocompound 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 0.5 to 1.5 percent.[181]

Selective catalytic reduction: This technology is common on 2010 heavy-duty diesel engines. Because SCR is a highly effective NOX aftertreatment approach, it enables engines to be optimized to maximize fuel efficiency, rather than minimize engine-out NOX. 2010 SCR systems are estimated to result in improved engine efficiency of approximately 4 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.[182] As more effective low-temperature catalysts are developed, the NOX conversion efficiency of the SCR system will increase. Next-generation SCR systems could then enable still further 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.[183] The agencies also estimate that continued refinement and optimization of the SCR systems could provide an additional 2 percent reduction in the 2017 model year.

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Improved Combustion Process: Fuel consumption reductions in the range of 1 to 4 percent 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.[184]

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.[185]

(2) What is the projected technology package's effectiveness and cost?

(a) Vocational Vehicles

(i) Baseline Vocational Vehicle Performance

The baseline vocational vehicle model is defined in GEM, as described in draft RIA Chapter 4.4.6. The agencies used a baseline rolling resistance coefficient for today's vocational vehicle fleet of 9 kg/metric ton.[186] Further vehicle technology is not included in this baseline, as discussed below in the discussion of the baseline vocational vehicle. The baseline engine fuel consumption represents a 2010 model year diesel engine, as described in draft RIA Chapter 4. Using these values, the baseline performance of these vehicles is included in Table III-12.

(ii) Vocational Vehicle Technology Package

The proposed program for vocational vehicles for this phase of regulatory standards is limited to performance of tire and engine technologies. Aerodynamics technology, weight reduction, drive train improvement, and hybrid power trains are not included for the reasons discussed above in Section III.C(1). The agencies are seeking comment on the appropriateness of this approach.

The assessment of the proposed technology effectiveness was developed through the use of the GEM. To account for the two proposed engine standards, EPA is proposing the use of a 2014 model year fuel consumption map in GEM to derive the 2014 model year truck standard and a 2017 model year fuel consumption map to derive the 2017 model year truck standard. (These fuel consumption maps reflect the main standards proposed for HD diesel engines, not the alternative standards.) EPA estimates that the rolling resistance of tires can be reduced by 10 percent in the 2014 model year. The vocational vehicle standards for all three regulatory categories were determined using a tire rolling resistance coefficient of 8.1 kg/metric ton with a 100 percent application rate by the 2014 model year. The set of input parameters which are modeled in GEM are shown in Table III-13.

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The agencies developed the proposed standards by using the engine and tire rolling resistance inputs in the GEM, as shown in Table III-13. The percent reductions shown in Table III-14 reflect improvements over the 2010 model year baseline vehicle with a 2010 model year baseline engine.

(iii) Technology Package Cost

EPA and NHTSA developed the costs of LRR tires based on the ICF report. The estimated cost per truck is $155 (2008$) for LHD and MHD trucks and $186 (2008$) for HHD trucks. These costs include a low complexity ICM of 1.14 and are applicable in the 2014 model year.

(iv) Reasonableness of the Proposed Standards

The proposed standards would not only add only a small amount to the vehicle cost, but are highly cost effective, an estimated $20 ton of CO2 eq per vehicle in 2030.[187] This is even less than the estimated cost effectiveness for CO2 eq removal under the light-duty vehicle rule, already considered by the agencies to be a highly cost effective reduction.[188] Moreover, the modest cost of controls is recovered almost immediately due to the associated fuel savings, as shown in the payback analysis included in Table VIII-7. Given that the standards are technically feasible within the lead time afforded by the 2014 model year, are inexpensive and highly cost effective, and do not have other adverse potential impacts (e.g., there are no projected negative impacts on safety or vehicle utility), the proposed standards represent a reasonable choice under section 202(a) of the CAA and NHTSA's EISA authority under 49 U.S.C. 32902(k)(2), and the agencies believe that the standards are consistent with their respective authorities.

(v) Alternative Vehicle Standards Considered

The agencies are not proposing vehicle standards less stringent than the proposed standards because the agencies believe these standards are highly cost effective, as just explained.

The agencies considered proposing truck standards which are more stringent reflecting the inclusion of hybrid powertrains in those vocational vehicles where use of hybrid powertrains is appropriate. The agencies estimate that a 25 percent utilization rate of hybrid powertrains in MY 2017 vocational vehicles would add, on average, $30,000 to the cost of each vehicle and more than double the cost of the rule for this sector. See the draft RIA at Chapter 6.1.8. The emission reductions associated with these very high costs appear to be modest. See the draft RIA Table 6-14. In addition, the agencies are proposing flexibilities in the form of generally applicable credit opportunities for advanced technologies, to encourage use of hybrid powertrains. See Section IV.C.2 below. The agencies welcome comments on whether hybrid powertrain technologies are appropriate to consider for the 2017 model year standard, or if not, then when would they be appropriate.

(b) Gasoline Engines

(i) Baseline Gasoline Engine Performance

EPA and NHTSA developed the reference heavy-duty gasoline engines to represent a 2010 model year engine compliant with the 0.2 g/bhp-hr NOX standard for on-highway heavy-duty engines.

NHTSA and EPA developed the baseline fuel consumption and CO2 emissions for the gasoline engines from manufacturer reported CO2 values used in the certification of non-GHG pollutants. The baseline engine for the analysis was developed to represent a 2011 model year engine, because this is the most current information available. The average CO2 performance of the heavy-duty gasoline engines was 660 g/bhp-hour, which will be used as a baseline. The baseline gasoline engines are all stoichiometric port fuel injected V-8 engines without cam phasers or other variable valve timing technologies. While they may reflect some degree of static valve timing optimization for fuel efficiency they do not reflect the potential to adjust timing with engine speed.

(ii) Gasoline Engine Technology Package Effectiveness

The gasoline engine technology package includes engine friction reduction, coupled cam phasing, and SGDI to produce an overall five percent reduction from the reference engine based on the Heavy-duty Lumped Parameter model. The agencies are projecting a 100% application rate of Start Printed Page 74246this technology package to the heavy-duty gasoline engines, which results in a CO2 standard of 627 g/bhp-hr and a fuel consumption standard of 7.05 gallon/100 bhp-hr. As discussed in Section II.D.b.ii, the agencies propose that the gasoline engine standards begin in the 2016 model year based on the agencies' projection of the engine redesign schedules of the small number of engines in this category.

(iii) Gasoline Engine Technology Package Cost

For costs, the agencies reconsidered both the direct or “piece” costs and indirect costs of individual components of technologies. For the direct costs, the agencies followed a BOM approach employed by NHTSA and EPA in the 2012-2016 LD rule. NHTSA and EPA are proposing to use the marked up gasoline engine technology costs developed for the HD Pickup Truck and Van segment because they are made by the same manufacturers (primarily by Ford and GM) and, the same products simply sold as loose engines rather than complete vehicles. Hence the engine cost estimates are fundamentally the same. The costs are summarized in Table III-15. The costs shown in Table III-15 include a low complexity ICM of 1.17 and are applicable in the 2016 model year. No learning effects are applied to engine friction reduction costs, while time based learning is considered applicable to both coupled cam phasing and SGDI.

(iv) Reasonableness of the Proposed Standard

The proposed engine standards appear to be reasonable and consistent with the agencies' respective authorities. With respect to the 2016 MY standard, all of the technologies on which the standards are predicated have been demonstrated and their effectiveness is well documented. The proposal reflects a 100 percent application rate for these technologies. The costs of adding these technologies remain modest across the various engine classes as shown in Table III-15. Use of these technologies would add only a small amount to the cost of the vehicle,[189] and the associated reductions are highly cost effective, an estimated $30 per ton of CO2 eq per vehicle.[190] This is even more cost effective than the estimated cost effectiveness for CO2 eq removal and fuel economy improvement under the light-duty vehicle rule, already considered by the agencies to be a highly cost effective reduction.[191] Accordingly, EPA and NHTSA view these standards as reflecting an appropriate balance of the various statutory factors under section 202(a) of the CAA and under NHTSA's EISA authority at 49 U.S.C. 32902(k)(2).

(v) Alternative Gasoline Engine Standards Considered

The agencies are not proposing gasoline standards less stringent than the proposed standards because the agencies believe these standards are feasible in the lead time provided, inexpensive, and highly cost effective. We welcome comments supplemented with data on each aspect of this determination most importantly on individual gasoline engine technology efficacy to reduce fuel consumption and GHGs as well was our estimates of individual technology cost and lead-time.

The proposed rule reflects 100 percent penetration of the technology package on whose performance the standard is based, so some additional technology would need to be added to obtain further improvements. The agencies considered proposing gasoline engine standards which are more stringent reflecting the inclusion of cylinder deactivation and other advanced technologies. However, the agencies are not proposing this level of stringency because our assessment is that these technologies would not be available for production by the 2017 model year. The agencies welcome comments on whether other gasoline technologies are appropriate to consider for the 2017 model year standard, or if not, then when would they be appropriate.

(c) Diesel Engines

(i) Baseline Diesel Engine Performance

EPA and NHTSA developed the baseline heavy-duty diesel engines to represent a 2010 model year engine compliant with the 0.2 g/bhp-hr NOX standard for on-highway heavy-duty engines.

The agencies utilized 2007 through 2011 model year CO2 certification levels from the Heavy-duty FTP cycle as the basis for the baseline engine CO2 performance. The pre-2010 data are subsequently adjusted to represent 2010 model year engine maps by using predefined technologies including SCR and other systems that are being used in current 2010 production. The engine CO2 results were then sales weighted within each regulatory subcategory to develop an industry average 2010 model year reference engine, as shown in Table III-16. The level of CO2 emissions and fuel consumption of these engines varies significantly, where the engine with the highest CO2 emissions is estimated to be 20 percent greater than the sales weighted average. Details of this analysis are included in draft RIA Chapter 2.

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(ii) Diesel Engine Packages

The diesel engine technology packages for the 2014 model year include engine friction reduction, improved aftertreatment effectiveness, improved combustion processes, and low temperature EGR system optimization. The improvements in parasitic and friction losses come through piston designs to reduce friction, improved lubrication, and improved water pump and oil pump designs to reduce parasitic losses. The aftertreatment improvements are available through lower backpressure of the systems and optimization of the engine-out NOX levels. Improvements to the EGR system and air flow through the intake and exhaust systems, along with turbochargers can also produce engine efficiency improvements. It should be pointed out that individual technology improvements are not additive to each other due to the interaction of technologies. The agencies assessed the impact of each technology over the Heavy-duty FTP and project an overall cycle improvement in the 2014 model year of 3 percent for HHD diesel engines and 5 percent for LHD and MHD diesel engines, as detailed in draft RIA Chapter 2.4.2.9 and 2.4.2.10. EPA used a 100 percent application rate of this technology package to determine the level of the proposed 2014 MY standards

Recently, EPA's heavy-duty highway engine program for criteria pollutants provided new emissions standards for the industry in three year increments. The heavy-duty engine manufacturer product plans have fallen into three year cycles to reflect this environment. EPA is proposing set CO2 emission standards recognizing the opportunity for technology improvements over this timeframe while reflecting the typical heavy-duty engine manufacturer product plan cycles. Thus, the agencies are proposing to establish initial standards for the 2014 model year and a more stringent standard for heavy-duty engines beginning in the 2017 model year.

The 2017 model year technology package for LHD and MHD diesel engine includes continued development and refinement of the 2014 model year technology package, in particular the additional improvement to aftertreatment systems. This package leads to a projected 9 percent reduction for LHD and MHD diesel engines in the 2017 model year. The HHD diesel engine technology packages for the 2017 model year include the continued development of the 2014 model year technology package plus turbocompounding. A similar approach to evaluating the impact of individual technologies as taken to develop the overall reduction of the 2014 model year package was taken with the 2017 model year package. The Heavy-duty FTP cycle improvements lead to a 5 percent reduction on the cycle for HHDD, as detailed in draft RIA Chapter 2.4.2.13. The agencies used a 100 percent application rate of the technology package to determine the proposed 2017 MY standards. The agencies believe that bottom cycling technologies are still in the development phase and will not be ready for production by the 2017 model year.[192] Therefore, these technologies were not included in determining the stringency of the proposed standards. However, we do believe the bottoming cycle approach represents a significant opportunity to reduce fuel consumption and GHG emissions in the future. EPA and NHTSA are therefore both proposing provisions described in Section IV to create incentives for manufacturers to continue to invest to develop this technology.

The overall projected improvements in CO2 emissions and fuel consumption over the baseline are included in Table III-17.

(iii) Technology Package Costs

NHTSA and EPA jointly developed costs associated with the engine technologies to assess an overall package cost for each regulatory category. Our engine cost estimates for diesel engines used in vocational vehicles include a separate analysis of the incremental part costs, research and development activities, and additional equipment, such as emissions equipment to measure N2 O emissions. Our general approach used elsewhere in this proposal (for HD pickup trucks, gasoline engines, Class 7 and 8 tractors, and Class 2b-8 vocational vehicles) estimates a direct manufacturing cost for a part and marks it up based on a factor to account for indirect costs. See also 75 FR 25376. We believe that approach is Start Printed Page 74248appropriate when compliance with proposed standards is achieved generally by installing new parts and systems purchased from a supplier. In such a case, the supplier is conducting the bulk of the research and development on the new parts and systems and including those costs in the purchase price paid by the original equipment manufacturer. The indirect costs incurred by the original equipment manufacturer need not include much cost to cover research and development since the bulk of that effort is already done. For the MHD and HHD diesel engine segment, however, the agencies believe we can make a more accurate estimate of technology cost using this alternate approach because the primary cost is not expected to be the purchase of parts or systems from suppliers or even the production of the parts and systems, but rather the development of the new technology by the original equipment manufacturer itself. Therefore, the agencies believe it more accurate to directly estimate the indirect costs. EPA commonly uses this approach in cases where significant investments in research and development can lead to an emission control approach that requires no new hardware. For example, combustion optimization may significantly reduce emissions and cost a manufacturer millions of dollars to develop but will lead to an engine that is no more expensive to produce. Using a bill of materials approach would suggest that the cost of the emissions control was zero reflecting no new hardware and ignoring the millions of dollars spent to develop the improved combustion system. Details of the cost analysis are included in the draft RIA Chapter 2. To reiterate, we have used this different approach because the MHD and HHD diesel engines are expected to comply in large part via technology changes that are not reflected in new hardware but rather knowledge gained through laboratory and real world testing that allows for improvements in control system calibrations—changes that are more difficult to reflect through direct costs with indirect cost multipliers.

The agencies developed the engineering costs for the research and development of diesel engines with lower fuel consumption and CO2 emissions. The aggregate costs for engineering hours, technician support, dynamometer cell time, and fabrication of prototype parts are estimated at $6,750,000 per manufacturer per year over the five years covering 2012 through 2016. In aggregate, this averages out to $280 per engine during 2012 through 2016 using a very rough annual sales value of 600,000 LHD, MHD and HHD diesel engines. The agencies also are estimating costs of $100,000 per engine manufacturer per engine class (LHD, MHD and HHD diesel) to cover the cost of purchasing photo-acoustic measurement equipment for two engine test cells. This would be a one-time cost incurred in the year prior to implementation of the standard (i.e., the cost would be incurred in 2013). In aggregate, this averages out to $4 per engine in 2013 using a very rough annual sales value of 600,000 LHD, MHD and HHD diesel engines.

EPA also developed the incremental piece cost for the components to meet each of the 2014 and 2017 standards. These costs shown in Table III-18 which include a low complexity ICM of 1.11; time based learning is considered applicable to each technology.

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The overall costs for each diesel engine regulatory subcategory are included in Table III-19.

(iv) Reasonableness of the Proposed Standards

The proposed engine standards appear to be reasonable and consistent with the agencies' respective authorities. With respect to the 2014 and 2017 MY standards, all of the technologies on which the standards have already been demonstrated and their effectiveness is well documented. The proposal reflects a 100 percent application rate for these technologies. The costs of adding these technologies remain modest across the various engine classes as shown in Table III-19. Use of these technologies would add only a small amount to the cost of the vehicle,[193] and the associated reductions are highly cost effective, an estimated $30 per ton of CO2 eq per vehicle.[194] This is even more cost effective than the estimated cost effectiveness for CO2 eq removal and fuel economy improvement under the light-duty vehicle rule, already considered by Start Printed Page 74250the agencies to be a highly cost effective reduction.[195] Accordingly, EPA and NHTSA view these standards as reflecting an appropriate balance of the various statutory factors under section 202(a) of the CAA and under NHTSA's EISA authority at 49 U.S.C. 32902(k)(2).

(v) Alternative Diesel Engine Standards Considered

Other than the specific proposal related to legacy engine products, the agencies are not proposing diesel engine standards less stringent than the proposed standards because the agencies believe these standards are highly cost effective. We welcome comments supplemented with data on each aspect of this determination most importantly on individual engine technology efficacy to reduce fuel consumption and GHGs as well as our estimates of individual technology cost and lead-time.

The agencies considered proposing diesel engine standards which are more stringent reflecting the inclusion of other advanced technologies. However, the agencies are not proposing this level of stringency because our assessment is that these technologies would not be available for production by the 2017 model year. The agencies welcome comments on whether other diesel engine technologies are appropriate to consider for the 2017 model year standard, or if not, then when would they be appropriate.

IV. Proposed Regulatory Flexibility Provisions

This section discusses proposed flexibility provisions intended to achieve the goals of the overall program while providing alternate pathways to achieve those goals. The primary flexibility provisions the agencies are proposing for combination tractors and vocational vehicles relate to a program of Averaging, Banking, and Trading of credits that EPA and NHTSA are proposing in association with each agency's respective CO2 and fuel consumption standards (see Section II above). For HD pickups and vans, the primary flexibility provision is the fleet averaging program patterned after the LD GHG and CAFE rule. EPA is not proposing an emission credit program associated with the proposed N2 O, CH4, or HFC standards. This section also describes proposed flexibility provisions that would apply in specific circumstances.

A. Averaging, Banking, and Trading Program

Averaging, Banking, and Trading (ABT) of emissions credits have been an important part of many EPA mobile source programs under CAA Title II, including engine and vehicle programs. ABT programs can be important because they can help to address many issues of technological feasibility and lead-time, as well as considerations of cost. ABT programs are not just add-on provisions included to help reduce costs, but are usually an integral part of the standard setting itself. An ABT program is important because it provides manufacturers flexibilities that assist the development and implementation of new technologies efficiently and therefore enables new technologies to be implemented at a more progressive pace than without ABT. A well-designed ABT program can provide important environmental benefits and at the same time increase flexibility for and reduce costs to the regulated industry.

Section II above describes EPA's proposed GHG emission standards and NHTSA's proposed fuel consumption standards. For each of these respective sets of standards, the agencies are also proposing ABT provisions consistent with each agency's statutory authority. The agencies have worked closely together to design these proposed provisions to be essentially identical to each other in form and function. Because of this fundamental similarity, the remainder of this section refers to these provisions collectively as “the ABT program” except where agency-specific distinctions are required.

As discussed in detail below, the structure of this proposed GHG ABT program for HD engines is based closely on earlier ABT programs for HD engines; the proposed program for HD pickups and vans is built on the existing light-duty GHG program flexibility provisions; and we propose first-time ABT provisions for combination tractors and vocational vehicles that are as consistent as possible with our other HD vehicle regulations. The flexibility provisions associated with this new regulatory category are intended to systematically build upon the structure of the existing programs.

As an overview, “averaging” means the exchange of emission credits between engine families or truck families within a given manufacturer's regulatory subcategory. For example within each regulatory subcategory, engine manufacturers divide their product line into “engine families” that are comprised of engines expected to have similar emission characteristics throughout their useful life. Averaging allows a manufacturer to certify one or more engine families within the same regulatory subcategory at levels above the applicable emission standard. The increased emissions over the standard would need to be offset by one or more engine families within that manufacturer's regulatory subcategory that are certified below the same emission standard, such that the average emissions from all the manufacturer's engine families, weighted by engine power, regulatory useful life, and production volume, are at or below the level of the emission standard. (The inclusion of engine power, useful life, and production volume in the averaging calculations allows the emissions credits or debits to be expressed in total emissions over the useful life of the credit-using or generating engine sales.) Total credits for each regulatory subcategory within each model year are determined by summing together the credits calculated for every engine family within that specific regulatory subcategory.

“Banking” means the retention of emission credits by the manufacturer for use in future model year averaging or trading. “Trading” means the exchange of emission credits between manufacturers, which can then be used for averaging purposes, banked for future use, or traded to another manufacturer.

In the current HD program for criteria pollutants, manufacturers are restricted to only averaging, banking and trading credits generated within a regulatory subcategory, and we are proposing to continue this restriction in the GHG and fuel consumption program. However, the agencies are evaluating—and therefore request comment on—potential alternative approaches in which fewer restrictions are placed on the use of credits for averaging, banking, and trading. Particularly, the agencies request comment on removing prohibitions on averaging and trading between some or all regulatory categories in this proposal, and on removing restrictions between some or all regulatory subcategories that are within the same regulatory category (e.g., allowing trading of credits between class 7 day cabs and class 8 sleeper cabs).

In the past, we have followed the practice of allowing averaging and trading between like products because we have recognized that the estimation of emissions credits is not an absolutely precise process, and actual emissions reductions or increases “in use” would vary due to differences in vehicle duty cycles, maintenance practices and any Start Printed Page 74251number of other factors. By restricting credit averaging and trading to only allow averaging and trading between like products, the agencies gain some degree of assurance that the operation and use of the vehicles generating credits and consuming credits would be similar. The agencies also note that some industry participants have expressed concern that allowing credit averaging, banking and trading across different products may create an unlevel playing field for the regulated industry. Specifically, engine and truck manufacturers have commonly expressed to us a concern that some manufacturers with a wide range of product offerings spanning a number of regulatory categories would be able to use the ABT program provisions to generate credits in regulatory class markets where they face less competition and then use those credits to compete unfairly in other regulatory categories where they face greater competition. Finally, in the context of regulating criteria pollutants that can have localized and regional impacts, we have been concerned about the unintended consequence of unrestricted credit averaging or trading on local or regional concentrations of pollutants, whereby emissions reductions might become concentrated in some localities or regions to the detriment of other areas needing the reductions.

The agencies are evaluating the possibility of placing fewer restrictions on averaging and trading because increasing the flexibility offered to manufacturers to average, bank, and trade credits across regulatory subcategories and categories could potentially significantly reduce the overall cost of the program. Specifically, we request comment on the extent to which a difference—or unexpected difference—in the marginal costs of compliance per gallon of fuel saved or ton of GHG reduced across categories or subcategories, combined with provision for averaging and trading across categories and subcategories, can allow manufacturers to achieve the same overall reduction in fuel use and emissions at lower cost.

While trading restrictions in the context of past EPA rulemakings have been motivated in part by the local or regional nature of the pollutant being regulated, in this instance, opportunities for greater flexibility may exist in light of the fact that greenhouse gases are a global pollutant for which local consequences are related to global, not local or regional atmospheric concentrations. However, trading ratios may need to be established for averaging and trading across categories, and potentially across subcategories, to ensure that averaging and trading across categories and subcategories does not lead to a net increase in emissions or fuel use in light of differences in vehicle use patterns across categories and subcategories. Further, it is possible to design trading ratios that ensure a net reduction in emissions and fuel use as a result of averaging and trading. The agencies also request comment on the potential additional savings in costs (beyond those already calculated in this proposal) due to increased flexibility in averaging and trading provisions, on how such averaging and trading flexibilities could be designed to ensure environmental neutrality, on whether trading ratios should be designed to achieve a net reduction in emissions and fuel use as a result of trading, on the concerns that have been raised by some regarding impacts on intra-industry competition, and on how to address the above identified concerns about dissimilarities in operation and use of vehicles.

(1) Heavy-duty Engines

For the heavy-duty engine ABT program, EPA and NHTSA are proposing to use EPA's existing regulatory engine classifications as the subcategory designations under this engine ABT program. The proposed regulations use the term “averaging set” which aligns with the regulatory subcategories or regulatory class in the context that they define the same set of products. The existing diesel engine subcategories are light-heavy-duty (LHD), medium-heavy-duty (MHD), and heavy-heavy-duty (HHD). LHD diesel engines are primarily used in vehicles with a GVWR below 19,500 lb. Vehicle body types in this group might include any heavy-duty vehicle built for a light-duty truck chassis, van trucks, multi-stop vans, recreational vehicles, and some single axle straight trucks. Vehicles containing these engines would normally include personal transportation, light-load commercial hauling and delivery, passenger service, agriculture, and construction applications.

MHD diesel engines are normally used in vehicles whose GVWR varies from 19,501-33,000 lb. Vehicles containing these engines typically include school buses, tandem axle straight trucks, city tractors, and a variety of special purpose vehicles such as small dump trucks, and trash compactor trucks. Normally the applications for these vehicles would include commercial short haul and intra-city delivery and pickup.

HHD diesel engines are intended for use in vehicles which exceed 33,000 lb GVWR. Vehicles containing engines of this type are normally tractors, trucks, and buses used in inter-city, long-haul applications. HHD engines are generally regarded as designed for rebuild and have a long useful life period. LHD and MHD engines are typically not intended for rebuild, though some MHD engines are designed for rebuild, and have a shorter useful life.

Gasoline or spark ignited engines for heavy-duty vehicles fall into one separate regulatory subcategory. These engines are typically installed in trucks with a GVWR ranging from 8,500 pounds to 19,500 pounds although they can be installed into trucks of any size.

The compliance program we are proposing would adopt a slightly different method for generating a manufacturer's CO2 emission and fuel consumption credit or deficit. The manufacturer's certification test result would serve as the basis for the generation of the manufacturer's Family Certification Level (FCL). The FCL is a new term we propose for this program to differentiate the purpose of this credit generation technique from the Family Emission Limit (FEL) previously used in a similar context in other EPA rules. A manufacturer could define its FCL at any level at or above the certification test result. Credits for the ABT program would be generated when the FCL is compared to its CO2 and fuel consumption standard, as discussed in Section II. The credits earned in this section would be restricted to the engine subcategory and not tradable with other engine subcategories consistent with EPA's past practice for ABT programs as described previously. Credit calculation for the proposed Engine ABT and program would be generated, either positive or negative, according to Equation IV-1 and Equation IV-2:

Equation IV-1: Proposed HD Engine CO2 credit (deficit)

HD Engine CO2 credit (deficit) (metric tons) = (Std−FCL) × (CF) × (Volume) × (UL) × (10−6)

Where:

Std = the standard associated with the specific engine regulatory subcategory (g/bhp-hr)

FCL = Family Certification Level for the engine family

CF = a transient cycle conversion factor in bhp-hr/mile which is the integrated total cycle brake horsepower-hour divided by the equivalent mileage of the Heavy-duty FTP cycle. For gasoline heavy-duty engines, the equivalent mileage is 6.3 miles. For diesel heavy-duty engines, the equivalent mileage is 6.5 miles. The agencies are proposing that the CF Start Printed Page 74252determined by the Heavy-duty FTP cycle be used for engines certifying to the SET standard.

Volume = (projected or actual) production volume of the engine family

UL = useful life of the engine (miles)

10−6 converts the grams of CO2 to metric tons

Equation IV-2: Proposed HD Engine Fuel Consumption credit (deficit) in gallons

HD Engine Fuel Consumption credit (deficit) (gallons) = (Std − FCL) × (CF) × (Volume) × (UL) × 102

Where:

Std = the standard associated with the specific engine regulatory subcategory (gallon/100 bhp-hr)

FCL = Family Certification Level for the engine family (gallon/100 bhp-hr)

CF = a transient cycle conversion factor in bhp-hr/mile which is the integrated total cycle brake horsepower-hour divided by the equivalent mileage of the Heavy-duty FTP cycle. For gasoline heavy-duty engines, the equivalent mileage is 6.3 miles. For diesel heavy-duty engines, the equivalent mileage is 6.5 miles. The agencies are proposing that the CF determined by the Heavy-duty FTP cycle be used for engines certifying to the SET standard.

Volume = (projected or actual) production volume of the engine family

UL = useful life of the engine (miles)

102 = conversion to gallons

To calculate credits or deficits, manufacturers would determine an FCL for each engine family they have designated for the ABT program. We have defined engine families in 40 CFR 1036.230 and manufacturers may designate how to group their engines for certification and compliance purposes. The FCL may be above (negative) or below (positive) its standard and would be used to establish the CO2 credits earned (or used) in Equation IV-1. The proposed CO2 and fuel consumption standards are associated with specific regulatory subcategories as described in Sections II.B and II.D (gasoline, light heavy-duty diesel, medium heavy-duty diesel, and heavy heavy-duty diesel). In the ABT program, engines certified with an FCL below the standard generate positive credits (g/bhp-hr and gal/100 bhp-hr). As discussed in Section II.B and II.D, engine families for which a manufacturer elects to use the alternative standard of a percent reduction from the engine family's 2011 MY baseline would be ineligible to either generate or use credits.

The volume used in Equations IV-1 and IV-2 refers to the total number of eligible engines sold per family participating in the ABT program during that model year. The useful life values in Equation IV-1 are proposed to be the same as the regulatory classifications previously used for the engine subcategories. Thus, the agencies propose that for LHD diesel engines and gasoline engines, the useful life values would be 110,000 miles; for MHD diesel engines, 185,000 miles; and for HHD diesel engines, 435,000 miles.

As noted above, credits generated by engine manufacturers under this ABT program would be restricted for use only within their engine subcategory based on performance against the standard as defined in Section II.B and II.D. Thus, LHD diesel engine manufacturers could only use their LHD diesel engine credits for averaging, banking and trading with LHD diesel engines, not with MHD diesel or HHD diesel engines. This limitation is consistent with ABT provisions in EPA's existing criteria pollutant program for engines and would help assure that credits earned to reduce GHG emissions and fuel consumption would be used to limit their growth and not circumvent the intent of the regulations. EPA and NHTSA are concerned that extending the use of credits beyond these designated subcategories could also create an advantage for large or integrated manufacturers that currently does not exist in the market. A manufacturer that produces both engines and heavy-duty highway vehicles could mix credits across engine and vehicle categories, shifting the burden between the sectors, not equally shared in either sector, to gain an advantage over competitors that are not integrated. Similarly, large volume manufacturers of engines can shift credits between heavy heavy-duty diesel engines and light heavy-duty diesel engines to gain an advantage in one subcategory over other manufacturers that may not have multiple engine offerings over several regulatory engine subcategories. Finally, relating credits between subcategories of engines could be problematic because of the differences in regulatory useful lives. The agencies want to avoid having credits from longer useful life categories flooding shorter useful life categories, adversely impacting compliance with the proposed CO2 and fuel consumption standards in the shorter useful life category. The agencies would like to ensure that this regulation reduces CO2 emissions and improves fuel consumption in each engine subcategory while not interfering with the ability of manufacturers to engage in free trade and competition. Limiting credit ABT to the regulatory subcategory and not between engines and vehicles would help prevent a competitive advantage due solely to the regulatory structure. Although the reasons for restricting engine credits to the same engine subcategory seem persuasive to us, the agencies welcome comments on the extension of credits beyond the limitations we are proposing.[196]

Under previous ABT programs for other rulemakings, EPA has allowed manufacturers to carry forward deficits from engines for a set period of time. The agencies are proposing to allow manufacturers of engines to carry forward deficits for up to three years before reconciling the short-fall. However, manufacturers would need to use credits, once credits are generated, to offset a shortfall before credits may be banked or traded for additional model years. This restriction reduces the chance of manufacturers passing forward deficits before reconciling shortfalls and exhausting those credits before reconciling past deficits. We will accept comments on alternative approaches for reconciling deficit shortfalls in the engine category.

As described in Section II above, EPA is proposing that a manufacturer may choose to comply with the N2 O or CH4 cap standards using CO2 credits. A manufacturer choosing this option would convert its N2 O or CH4 test results into CO2 eq to determine the amount of CO2 credits required. This approach recognizes the inter-correlation of these elements in impacting global warming. This option does not apply to the NHTSA fuel consumption program. To account for the different global warming potential of these GHGs, EPA proposes that manufacturers determine the amount of CO2 credits required by multiplying the shortfall by the GWP. For example, a manufacturer would use 25 kg of positive CO2 credits to offset 1 kg of negative CH4 credits. Or a manufacturer would use 298 kg of positive CO2 credits to offset 1 kg of negative N2 O credits. In general we do not expect manufacturers to use this provision. However, we are providing this alternative as a flexibility in the event an engine manufacturer has trouble meeting the CH4 and/or N2 O emission caps. There are not ABT credits for performance that falls below the CH4 or N2 O caps.

Additional flexibilities for engines are discussed later in Section IV(B).Start Printed Page 74253

(2) Class 7 and 8 Combination Tractors

In addition to the engine ABT program described above, the agencies are also proposing a vehicle ABT program to facilitate reductions in GHG emissions and fuel consumption based on combination tractor design changes and improvements. For this category, the structure of the proposed ABT program should create incentives for tractor manufacturers to advance new, clean technologies, or existing technologies earlier than they would otherwise.

As explained in Sections II and III above, combination tractor manufacturers are divided into nine regulatory subcategories under these proposed rules, as shown in the following table:

The proposed regulations use the term “averaging set” which aligns with the regulatory subcategories or regulatory class in the context that they define the same set of products. Vehicle credits for tractors in these classifications would be earned on a g/ton-mile or gallon/1,000 ton-mile basis for tractors which are below the standard. Credits generated within regulatory subcategories would be tradable between truck manufacturers in that specific regulatory subcategory only. Credits would not be fungible between engine and vehicle regulatory categories. This is similar to the restrictions we have described above for engine manufacturers.

This limitation would help ensure that credits earned to reduce GHG emissions and fuel consumption would be used to limit their growth and not circumvent the intent of our regulation. As with engine credits, we are concerned that extending the use of credits to be transferred or traded to other classes may create an advantage for large or integrated manufacturers that currently does not exist in the market. We would like to ensure that this regulation reduces the emission of CO2 and fuel consumption but does not effectively penalize non-integrated manufacturers and those with limited participation in the market. ABT provides manufacturers the flexilibility to deal with unforeseen shifts in the marketplace that affect sales volumes. This structure allows for a straightforward compliance program for each sector independently with aspects that are also independently quantifiable and verifiable. Credit calculation for the proposed Class 7 and 8 tractor CO2 and fuel consumption credits would be generated, either positive or negative, according to Equation IV-3 and Equation IV-4:

Equation IV-3: The Proposed Class 7 and 8 Tractor CO2 Credit (Deficit)

Class 7 and 8 Tractor CO2 credit (deficit)(metric tons) = (Std-FEL) × (Payload Tons) × (Volume) × (UL) × (10−6)

Where:

Std = the standard associated with the specific tractor regulatory class (g/ton-mile)

Payload tons = the prescribed payload for each class in tons (12.5 tons for Class 7 and 19 tons for Class 8)

FEL = Family Emission Limit for the tractor family which is equal to the output from GEM (g/ton-mile)

Volume = (projected or actual) production volume of the tractor family

UL = useful life of the tractor (435,000 miles for Class 8 and 185,000 miles for Class 7)

10-6 converts the grams of CO2 to metric tons

Equation IV-4: Proposed Class 7 and 8 Tractor Fuel Consumption credit (deficit) in gallons:

Class 7 and 8 Tractor Fuel Consumption credit (deficit)(gallons) = (Std−FEL) × (Payload Tons) × (Volume) × (UL) × 103

Where:

Std = the standard associated with the specific tractor regulatory subcategory (gallons/1,000 ton-mile)

Payload tons = the prescribed payload for each class in tons (12.5 tons for Class 7 and 19 tons for Class 8)

FEL = Family Emission Limit for the tractor family (gallons/1,000 ton-mile)

Volume = (projected or actual) production volume of the tractor family

UL = useful life of the tractor (435,000 miles for Class 8 and 185,000 miles for Class 7)

103 = conversion to gallons

Similar to the proposed Heavy-duty Engine ABT program described in the previous section, we are proposing that tractor manufacturers would be able to carry forward credit deficits from their regulatory subcategories for three years before reconciling the shortfall. However, just as in the engine category, manufacturers would need to use credits once those credits have been generated to offset a shortfall before those credits can be banked or traded for additional model years. This restriction reduces the chance of tractor manufacturers passing forward deficits before reconciling their shortfalls and exhausting those credits before reconciling past deficits. Manufacturers of vehicles that generate a deficit at the end of the model year could carry that deficit forward for three years following the model year for which that deficit was generated. Deficits would need to be reconciled at the reporting dates for year three. We will accept comments on alternative approaches of reconciling deficit shortfalls.

Additional flexibilities for Class 7 and 8 combination tractors are discussed later in Section IV.B.

(3) Class 2b-8 Vocational Vehicles

Similar to the Class 7 and 8 combination tractor manufacturers, we are offering a limited ABT program for Class 2b-8 vocational chassis manufacturers. Vehicle credits would be generated for those manufacturers that introduce products into the market with rolling resistance improvements which are better than required to meet the proposed vehicle standards, The certification of the chassis would be based on the use of LRR tires. Credit calculation for the proposed Class 2b-8 vocational vehicle CO2 and fuel consumption credits (deficits) would be generated, either positive or negative, according to Equation IV-5 and Equation IV-6:

Equation IV-5: The proposed Vocational Vehicle CO2 vehicle credit (deficit)

Vocational Vehicle CO2 credit (deficit) (metric tons) = (Std−FEL) × Start Printed Page 74254(Payload Tons) × (Sales Volume) × (UL) × (10-6)

Where:

Std = the standard associated with the specific vocational vehicle subcategory (g/ton-mile)

Payload tons = the prescribed payload for each subcategory in tons (2.85 tons for LHD, 5.6 tons for MHD, and 19 tons for HHD vehicles)

FEL = Family Emission Limit for the vehicle family (g/ton-mile)

Volume = (projected or actual) production volume of the vehicle family

UL = useful life of the vehicle (110,000 miles for LHD, 185,000 miles for MHD, or 435,000 miles for HHD vehicles)

10-6 converts the grams of CO2 to metric tons

Equation IV-6: Proposed Vocational Vehicle Fuel Consumption credit (deficit) in gallons

Vocational Vehicle Fuel Consumption credit for (deficit) (gallons) = (Std−FEL) × (Payload Tons) × (Sales Volume) × (UL) × 103

Where:

Std = the standard associated with the specific vocational vehicle regulatory subcategory (gallon/1,000 ton-mile)

Payload tons = the prescribed payload for each regulatory subcategory in tons (2.85 tons for LHD, 5.6 tons for MHD, and 19 tons for HHD vehicles)

FEL = Family Emission Limit for the vehicle family (gallon/1,000 ton-mile)

Volume = (projected or actual) production volume of the vehicle family

UL = useful life of the vehicle (110,000 miles for LHD, 185,000 miles for MHD, or 435,000 miles for HHD vehicles)

103 converts to gallons

Also, similar to the proposed heavy-duty engine and tractor ABT programs, the vehicle credits generated within each regulatory subcategory would be allowed to be averaged, banked, or traded between chassis manufacturers within their existing subcategories. For vocational vehicles the proposed vehicle subcategories are based on the vehicle's GVWR. We are proposing three vehicle subcategories LHD with a GVWR less than or equal to 19,500 pounds, MHD vehicles with a GVWR greater than 19,500 and less than or equal to 33,000 pounds, and HHD vehicles with a GVWR greater than 33,000 pounds. These three weight categories would form the subcategories for vocational vehicles and are found in 40 CFR 1037.230. The proposed regulations use the term “averaging set” which aligns with the regulatory categories or regulatory class in the context that they define the same set of products.

Similar to the proposed Heavy-duty Engine ABT program above, vocational chassis manufacturers would be able to carry forward deficits for three years before reconciling the shortfall. However, just as in the engine category, manufacturers would need to use credits earned once those credits have been generated to offset a shortfall before those credits can be banked or traded for additional model years. This restriction reduces the chance of chassis manufacturers passing forward deficits before reconciling their shortfalls and exhausting those credits before reconciling past deficits. Manufacturers of vocational vehicles that generate a deficit at the end of the model year could carry that deficit forward for three years following the model year for which that deficit was generated. Deficits would need to be reconciled at the reporting dates for year three. We will accept comments on alternative approaches of reconciling deficit shortfalls.

(4) Heavy-Duty Pickup Truck and Van Flexibility Provisions

EPA and NHTSA are proposing specific flexibility provisions for manufacturers of HD pickups and vans, similar to provisions adopted in the recent rulemaking for light-duty car and truck GHGs and fuel economy. Additional flexibilities that apply to the broad range of heavy-duty vehicles, including HD pickups and vans, are discussed in Section IV.B. All of these flexibilities would help enable new technologies to be implemented faster and more cost-effectively than without a flexibility program, and also help manufacturers deal with unexpected shifts in sales.

A manufacturer's credit or debit balance would be determined by calculating their fleet average performance and comparing it to the manufacturer's CO2 and fuel consumption standards, as determined by their fleet mix, for a given model year. A target standard is determined for each vehicle with a unique payload, towing capacity and drive configuration. These unique targets, weighted by their associated production volumes, are summed at the end of the model year to derive the production volume-weighted manufacturer annual fleet average standard. A manufacturer would generate credits if its fleet average CO2 or fuel consumption level is lower than its standard and would generate debits if its fleet average CO2 or fuel consumption level is above that standard. The end-of-year reports would provide appropriate data to reconcile pre-compliance estimates with final model year figures. Similar to the light-duty GHG program, the agencies would address any ultimate deficits by a possible void of certificates on a sufficient number of vehicles to address the shortfall. Enforcement action would entail penalty or other relief as appropriate or applicable.

In addition to production weighting, we are proposing that the EPA credit calculations include a factor for the vehicle useful life, in miles, in order to allow the expression of credits in metric tons, as in the light-duty GHG program. The NHTSA credit calculation would use standard and performance levels in fuel consumption units (gallons per 100 miles), as opposed to fuel economy units (mpg) as done in the light-duty program, along with the vehicle useful life, in miles, allowing the expression of credits in gallons. We propose that other provisions for the generation, tracking, trading, and use of the credits be the same as those adopted in the light-duty GHG program, including a 5-year limit on credit carry-forward to future model years and a 3-year limit on deficit carry-forward (or credit carry-back).

The total model year fleet credit (debit) calculations would use the following equations:

CO2 Credits (Mg) = [(CO2 Std−CO2 Act) × Volume × UL] ÷ 1,000,000

Fuel Consumption Credits (gallons) = (FC Std−FC Act) × Volume × UL × 100

Where:

CO2 Std = Fleet average CO2 standard (g/mi)

FC Std = Fleet average fuel consumption standard (gal/100 mile)

CO2 Act = Fleet average actual CO2 value (g/mi)

FC Act = Fleet average actual fuel consumption value (gal/100 mile)

Volume = the total production of vehicles in the regulatory class

UL = the useful life for the regulatory class (miles)

We are proposing that HD pickups and vans comprise a self-contained averaging set, such that credits earned may be used freely for other HD pickups and vans but not for other vehicles or engines, and credits generated by other vehicles or engines may not be used to demonstrate compliance for HD pickups and vans. We believe this approach is appropriate because the HD pickup and van fleet is relatively small and the balanced fleetwide averaging concept is critical for obtaining the desired technology development in the 2014-2018 timeframe, so that the potential for large credit flows into or out of this vehicle category would create unwarranted market uncertainty, which in turn could jeopardize the impetus to develop needed technologies. An exception to this approach is proposed for advanced technology credits as discussed in Section IV.B(2).Start Printed Page 74255

As described above, HD pickup and van manufacturers would be able to carry forward deficits from their fleet-wide average for three years before reconciling the shortfall. Manufacturers would be required to provide a plan in their pre-model year reports showing how they would resolve projected credit deficits. However, just as in the engine category, manufacturers would need to use credits earned once those credits have been generated to offset a shortfall before those credits can be banked or traded for additional model years. This restriction reduces the chance of vehicle manufacturers passing forward deficits before reconciling their shortfalls and exhausting those credits before reconciling past deficits. We request comments on all aspects of the proposed HD pickup and van credit program.

B. Additional Proposed Flexibility Provisions

The agencies are also proposing provisions to facilitate reductions in GHG emissions and fuel consumption beginning in the 2014 model year. While we view our proposed ABT and flexibility structure as sufficient to encourage reduction efforts by heavy-duty highway engine and vehicle manufacturers, we understand that other efforts may enhance the overall GHG and fuel consumption reduction we anticipate achieving. Therefore we propose the following flexibilities to create additional opportunities for manufacturers to reduce their GHG emissions and fuel consumption. These opportunities would help provide additional incentives for manufacturers to innovate and to develop new strategies and cleaner technologies.

(1) Early Credit Option

The agencies are proposing that manufacturers of HD engines, combination tractors, and vocational vehicles be eligible to generate early credits if they demonstrate improvements in excess of the proposed standards prior to model year they become effective. The start dates for EPA's GHG standards and NHTSA's fuel consumption standards vary by regulatory category (see Section II for the model years when the standards become effective). Specifically, manufacturers would need to certify their engines or vehicles to the standards at least six months before the start of the first model year of the mandatory standards. The limitations on the use of credits in the ABT programs—i.e., limiting averaging to within each the regulatory category and vehicle or engine subcategory—would apply for the proposed early credits as well.

NHTSA and EPA also request comment on whether a credit multiplier, specifically a multiplier of 1.5, would be appropriate to apply to early credits from HD engines, combination tractors, and vocational vehicles, as a greater incentive for early compliance. Additionally, the agencies seek comment on whether or not a requirement that HD engines, combination tractors, and vocational vehicles that are eligible to generate early credits, be allowed to do so only if they certify prior to June 1, 2013 should a multiplier of 1.5 be applied to early credits.

We are proposing that manufacturers of HD pickups and vans who demonstrate improvements for model year 2013 such that their fleet average emissions and fuel consumption are lower than the model year 2014 standards be eligible for early credits. Under the proposed structure for the fleet average standards, this credit opportunity would entail certifying a manufacturer's entire HD pickup and van fleet in model year 2013, and assessing this fleet against the model year 2014 target levels discussed in Section II. The agencies consider the proposed availability of early credits to be a valuable complement to the overall program to the extent that they encourage early implementation of effective technologies. We request comment on ways the early credit opportunities can be tailored to accomplish this objective and protect against unanticipated windfalls.

(2) Advanced Technology Credits

EPA and NHTSA are proposing targeted provisions that we expect would promote the implementation of advanced technologies. Specifically, manufacturers that incorporate these technologies would be eligible for special credits that could be applied to other heavy-duty vehicles or engines, including those in other heavy-duty categories. We seek comment on any conversion factors that may be needed. Technologies that we propose to make eligible are:

  • Hybrid powertrain designs that include energy storage systems.
  • Rankine cycle engines.
  • All-electric vehicles.
  • Fuel cell vehicles.

NHTSA and EPA request comment on whether a credit multiplier, specifically a multiplier of 1.5, would be appropriate to apply to advanced technology credits, as a greater incentive for their introduction. NHTSA and EPA request comment on the list of technologies identified as advanced technologies and whether additional technologies should be added to the list. NHTSA and EPA also request comment on whether credits generated from vehicles complying prior to 2014 and using Advanced SmartWay or Advanced SmartWay II aerodynamic technologies should be designated as Advanced Technology Credits.

(a) All-Electric Vehicles and HD Pickup Truck and Van Hybrids

For HD pickup and van hybrids, we propose that testing would be done using adjustments to the test procedures developed for light-duty hybrids. NHTSA and EPA are also proposing that all-electric and other zero emission vehicles produced in model years before 2014 be able to earn credits for use in the 2014 and later HD pickup and van compliance program, provided the vehicles are covered by an EPA certificate of conformity for criteria pollutants. These credits would be calculated based on the 2014 diesel standard targets corresponding to the vehicle's work factor, and treated as though they were earned in 2014 for purposes of credit life. Manufacturers would not have to early-certify their entire HD pickup and van fleet in a model year as for other early-complying vehicles. NHTSA and EPA are also proposing that model year 2014 and later EVs and other zero emission vehicles be factored into the fleet average GHG and fuel consumption calculations based on the diesel standards targets for their model year and work factor. If advanced technology credits generated by pickups and vans are used in another HD vehicle category, these credits would, of course, be subtracted from the manufacturer's pickup and van category credit balance.

In the 2012-2016 MY Light-Duty Vehicle Rule, EPA discussed at length the issue of whether to account for upstream emissions of GHGs in assessing the amount of credit to offer to various types of electric vehicles—that is, GHG emissions associated with generation of the electricity needed to power the electric vehicle. See 75 FR 25434-25436. Although acknowledging that such emissions would not be accounted for if electric vehicle GHG emissions are assessed at zero for credit generating purposes, EPA believed that this was the appropriate course in order to provide an incentive for commercialization of this extremely promising technology. At the same time, EPA adopted a cumulative cap whereby upstream emissions would be accounted for if sales of EVs exceeded a given amount.Start Printed Page 74256

The agencies believe that these same considerations apply to heavy-duty vehicles. Indeed, the agencies believe that introduction of EVs into the heavy-duty fleet would be less frequent than for light-duty vehicles, so that there is less risk of dilution of the main standards by unexpectedly high introduction of EVs into the heavy-duty fleet and at least an equally compelling reason to provide an incentive for the technology's commercial introduction. Given the unlikelihood of significant penetration of the technology in the model years of these standards, the agencies similarly do not see a need to adopt the type of cumulative caps which would trigger an upstream emission accounting procedure as in the light-duty vehicle rule. The agencies solicit comment on these issues, however.

(b) Vocational Vehicle and Tractor Hybrids

For vocational vehicles or combination tractors incorporating hybrid powertrains, we propose two methods for establishing the number of credits generated, each of which is discussed next. The agencies are not aware of models that have been adequately peer reviewed with data that can assess this technology without the conclusion of a comparison test of the actual physical product.

(i) Chassis Dynamometer Evaluation

For hybrid certification to generate credits we propose to utilize chassis testing as an effective way to compare the CO2 emissions and fuel consumption performance of conventional and hybrid vehicles. We are proposing that heavy-duty hybrid vehicles be certified using “A to B” vehicle chassis dynamometer testing. This concept allows a hybrid vocational vehicle manufacturer to directly quantify the benefit associated with use of its hybrid system on an application-specific basis. The concept would entail testing the conventional vehicle, identified as “A”, using the cycles as defined in Section V. The “B” vehicle would be the hybrid version of vehicle “A”. The “B” vehicle would need to be the same exact vehicle model as the “A” vehicle. As an alternative, if no specific “A” vehicle exists for the hybrid vehicle that is the exact vehicle model, the most similar vehicle model would need to be used for testing. We propose to define the “most similar vehicle” as a vehicle with the same footprint, same payload, same testing capacity, the same engine power system, the same intended service class, and the same coefficient of drag.

To determine the benefit associated with the hybrid system for GHG performance, the weighted CO2 emissions results from the chassis test of each vehicle would define the benefit as described below:

1. (CO2_A−CO2_B)/(CO2_A) = ____ (Improvement Factor)

2. Improvement Factor × GEM CO2 Result_B = ____ (g/ton mile benefit)

Similarly, the benefit associated with the hybrid system for fuel consumption would be determined from the weighted fuel consumption results from the chassis tests of each vehicle as described below:

3. (Fuel Consumption_A−Fuel Consumption_B)/(Fuel Consumption_A) = ____ (Improvement Factor)

4. Improvement Factor × GEM Fuel Consumption Result_B = ____ (gallon/1,000 ton mile benefit)

The credits for the hybrid vehicle would be calculated as described in the ABT program by Equation IV-5 and Equation IV-6, except that the result from Equation 2 above replaces the (Std-FEL) value. We are proposing that the tons of CO2 or gallons of fuel credits generated by a hybrid vehicle could flow into any regulatory subcategory.

The agencies are proposing two sets of duty cycles to evaluate the benefit depending on the vehicle application to assess hybrid vehicle performance—without and with PTO systems. The key difference between these two sets of vehicles is that one set (e.g., delivery trucks) does not operate a PTO while the other set (e.g., bucket and refuse trucks) does.

The first set of duty cycles would apply to the hybrid powertrains used to improve the motive performance of the vehicles without a PTO system (such as pickup and delivery trucks). The typical operation of these vehicles is very similar to the overall drive cycles proposed in Section II. Therefore, the agencies are proposing to use the same vehicle drive cycle weightings for testing these vehicles, as shown in Table IV-2.

The second set of duty cycles apply to testing hybrid vehicles used in applications such as utility and refuse trucks tend to have additional benefits associated with use of stored energy, which avoids main engine operation and related CO2 emissions and fuel consumption during PTO operation. To appropriately address benefits, exercising the conventional and hybrid vehicles using their PTO would help to quantify the benefit to GHG emissions and fuel consumption reductions. The duty cycle proposed to quantify the hybrid CO2 and fuel consumption impact over this broader set of operation would be the three primary drive cycles plus a PTO duty cycle. Our proposed PTO cycle is based on consideration of using alternate, appropriate duty cycles with Administrator approval in a public process. The PTO duty cycle as proposed takes into account the sales impact and population of utility trucks and refuse haulers. As described in draft RIA Chapter 3, the agencies are proposing to add an additional PTO cycle to measure the improvement achieved for this type of hybrid powertrain application. The proposed weightings for the hybrids with PTO are included in Table IV-3. The agencies welcome comments on the proposed drive cycle weightings and the proposed PTO cycle.

Start Printed Page 74257

(ii) Engine Dynamometer Evaluation

The engine test procedure we are proposing for hybrid evaluation involves exercising the conventional engine and hybrid-engine system based on an engine testing strategy. The basis for the system control volume, which serves to determine the valid test article, would need to be the most accurate representation of real world functionality. An engine test methodology would be considered valid to the extent the test is performed on a test article that does not mischaracterize criteria pollutant performance or actual system performance. Energy inputs should not be based on simulation data which is not an accurate reflection of actual real world operation. It is clearly important to be sure credits are generated based on known physical systems. This includes testing using recovered vehicle kinetic energy. Additionally, the duty cycle over which this engine-hybrid system would be exercised would need to reflect the use of the application, while not promoting a proliferation of duty cycles which prevent a standardized basis for comparing hybrid system performance. The agencies are proposing the use of the Heavy-duty FTP cycle for evaluation of hybrid vehicles, which is the same test cycle proposed for engines used in vocational vehicles. For powerpack testing, which includes the engine and hybrid systems in a pre-transmission format, the engine based testing is applicable for determination of brake-specific emissions benefit versus the engine standard. For post-transmission powertrain systems and vehicles, the comparison evaluation based on the Improvement Factor and the GEM result based on a vehicle drive trace in a powertrain test cell or chassis dynamometer test cell seem to accurately reflect the performance improvements associated with these test configurations. It is important that introduction of clean technology be incentivized without compromising the program intent of real world improvements in GHG and fuel consumption performance. The agencies seek comments on the most appropriate test procedures to accurately reflect the performance improvement associated with hybrid systems tested using these or other protocols.

(3) Innovative Technology Credits

NHTSA and EPA are proposing a credit opportunity intended to apply to new and innovative technologies that reduce fuel consumption and CO2 emissions, but for which the reduction benefits are not captured over the test procedure used to determine compliance with the standards (i.e., the benefits are “off-cycle”). See 75 FR 25438-25440 where EPA adopted a similar credit program for MY 2012-2016 light-duty vehicles. In this case, the `test procedure' includes not only the Heavy-duty FTP and SET procedures used to measure compliance with the engine standards, but also the GEM. Eligible innovative technologies would be those that are newly introduced in one or more vehicle models or engines, but that are not yet widely implemented in the heavy-duty fleet. This could include known technologies not yet widely utilized in a particular subcategory. Further, any credits for these off-cycle technologies would need to be based on real-world fuel consumption and GHG reductions that can be measured with verifiable test methods and representing driving conditions typical of the vehicle application.

We would not consider technologies to be eligible for these credits if the technology has a significant impact on CO2 emissions and fuel consumption over the primary test cycles or are the technologies on whose performance the various vehicle and engine standards are premised. However, EPA and NHTSA are aware of some emerging and innovative technologies and concepts in various stages of development with CO2 emissions and fuel consumption reduction potential that might not be adequately captured on the proposed certification test cycles, and we believe that some of these technologies might merit some additional CO2 and fuel consumption credit generating potential for the manufacturer. Examples include predictive cruise control, gear-down protection, and active aerodynamic features not exercised in the certification test, such as adjustable ride height for pickup trucks. We believe it would be appropriate to provide an incentive to encourage the introduction of these types of technologies and that a credit mechanism is an effective way to do so. This optional credit opportunity would be available through the 2018 model year reflecting that technologies may be common by then, but the agencies welcome comment on the need to extend beyond model year 2018.

EPA and NHTSA propose that credits generated using innovative technologies be restricted within the subcategory where the credit was generated. The agencies request comments whether credits generated using innovative technologies should be fungible across vehicle and engine categories.

We are proposing that manufacturers quantify CO2 and fuel consumption reductions associated with the use of the off-cycle technologies such that the credits could be applied based on the proposed metrics (such as g/mile and gal/100 mile for pickup trucks, g/ton-mile and gal/1,000 ton-mile for tractors and vocational vehicles, and g/bhp-hr and gal/100 bhp-hr for engines). Credits would have to be based on real additional reductions of CO2 emissions and fuel consumption and would need to be quantifiable and verifiable with a repeatable methodology. Such submissions of data should be submitted to EPA and NHTSA, and would be subject to a public evaluation process in which the public would have opportunity for comment. See 75 FR 25440. We propose that the technologies upon which the credits are based would be subject to full useful life compliance provisions, as with other emissions controls. Unless the manufacturer can demonstrate that the technology would not be subject to in-use deterioration over the useful life of the vehicle, the manufacturer would have to account for deterioration in the estimation of the credits in order to ensure that the credits are based on real in-use emissions reductions over the life of the vehicle.

In cases where the benefit of a technological approach to reducing CO2 emissions and fuel consumption cannot be adequately represented using existing test cycles, EPA and NHTSA would review and approve as appropriate test procedures and analytical approaches to estimate the effectiveness of the technology for the purpose of generating credits. The demonstration program should be robust, verifiable, and capable of demonstrating the real-world emissions benefit of the technology with strong statistical significance. See 75 FR Start Printed Page 7425825440. For HD pickups and vans, EPA and NHTSA believe that the 5-cycle approach currently used in EPA's fuel economy labeling program for light-duty vehicles may provide a suitable test regimen, provided it can be reliably conducted on the dynamometer and can capture the impact of the off-cycle technology (see 71 FR 77872, December 27, 2006). EPA established the 5-cycle test methods to better represent real-world factors impacting fuel economy, including higher speeds and more aggressive driving, colder temperature operation, and the use of air conditioning.

The CO2 and fuel consumption benefit of some technologies may be able to be demonstrated with a modeling approach. In other cases manufacturers might have to design on-road test programs that are statistically robust and based on real-world driving conditions. Whether the approach involves on-road testing, modeling, or some other analytical approach, the manufacturer would be required to present a proposed methodology to EPA and NHTSA. EPA and NHTSA would approve the methodology and credits only if certain criteria were met. Baseline emissions and control emissions would need to be clearly demonstrated over a wide range of real-world driving conditions and over a sufficient number of vehicles to address issues of uncertainty with the data. Data would need to be on a vehicle model-specific basis unless a manufacturer demonstrated model-specific data was not necessary. Approval of the approach to determining a CO2 and fuel consumption benefit would not imply approval of the results of the program or methodology; when the testing, modeling, or analyses are complete the results would likewise be subject to EPA and NHTSA review and approval. The agencies believe that suppliers and vehicle manufacturers could work together to develop testing, modeling, or analytical methods for certain technologies, similar to the SAE approach used for A/C refrigerant leakage scores. As with the similar procedure for alternative off-cycle credits under the 2012-2016 MY light-duty vehicle program, the agencies would include an opportunity for public comment as part of any approval process.

The agencies request comments on the proposed approach for off-cycle emissions credits, including comments on how best to structure the program. EPA and NHTSA particularly request comments on how the case-by-case approach to assessing off-cycle innovative technology credits could best be designed, including ways to ensure the verification of real-world emissions benefits and to ensure transparency in the process of reviewing manufacturers' proposed test methods.

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

A. Overview

(1) Proposed Compliance Approach

This section describes EPA's and NHTSA's proposed program to ensure compliance with EPA's proposed emission standards for CO2, N2 O, and CH4 and NHTSA's proposed fuel consumption standards, as described in Section II. To achieve the goals projected in this proposal, it is important for the agencies to have an effective and coordinated compliance program for our respective standards. As is the case with the Light-Duty GHG and CAFE program, the proposed compliance program for heavy-duty vehicles and engines has two central priorities. (1) To address the agencies' respective statutory requirements; and (2) to streamline the compliance process for both manufacturers and the agencies by building on existing practice wherever possible, and by structuring the program such that manufacturers can use a single data set to satisfy the requirements of both agencies. It is also important to consider the provisions of EPA's existing criteria pollutant program in the development of the approach used for heavy-duty certification and compliance. The existing EPA heavy-duty highway engine emissions program has an established infrastructure and methodology that would allow effective integration with this proposed GHG and fuel consumption program, without needing to create new unique processes in many instances. The compliance program would also need to address the importance of the impact of new control methods for heavy-duty vehicles as well as other control systems and strategies that may extend beyond the traditional purview of the criteria pollutant program.

The proposed heavy-duty compliance program would use a variety of mechanisms to conduct compliance assessments, including preproduction certification and postproduction, in-use monitoring once vehicles enter customer service. Specifically, the agencies are establishing a compliance program that utilizes existing EPA testing protocols and certification procedures. Under the provisions of this program, manufacturers would have significant opportunity to exercise implementation flexibility, based on the program schedule and design, as well as the credit provisions that are being proposed in the program for advanced technologies. This proposal includes a process to foster the use of innovative technologies, not yet contemplated in the current certification process. EPA would continue to conduct compliance preview meetings which provide the agency an opportunity to review a manufacturer's new product plans and ABT projections. Given the nature of the proposed compliance program which would involve both engine and vehicle compliance for some categories, it would be necessary for manufacturers to begin pre-certification meetings with EPA early enough to address issues of certification and compliance for both integrated and non-integrated product offerings.

Based on feedback EPA and NHTSA received during the Light-Duty GHG comment period, both agencies would seek to ensure transparency in the compliance process. In addition to providing information in published reports annually regarding the status of credit balances and compliance on an industry basis, EPA and NHTSA seek comment on additional strategies for providing information useful to the public regarding industry's progress toward reducing GHG emissions and fuel consumption from this sector while protecting sensitive business information.

(a) Heavy-Duty Pickup Trucks and Vans

The proposed compliance regulations (for certification, testing, reporting, and associated compliance activities) for heavy-duty pickup trucks and vans closely track both current practices and the recently adopted greenhouse gas regulations for light-duty vehicles and trucks. Thus they would be familiar to manufacturers. EPA already oversees testing, collects and processes test data, and performs calculations to determine compliance with both CAFE and CAA standards for Light-Duty. For Heavy-Duty products that closely parallel light-duty pick-ups and vans, under a coordinated approach, the compliance mechanisms for both programs for NHTSA and EPA would be consistent and non-duplicative for GHG pollutant standards and fuel consumption requirements. Vehicle emission standards established under the CAA apply throughout a vehicle's full useful life.

Under EPA existing criteria pollutant emission standard program for heavy-duty pickup trucks and vans, vehicle manufacturers certify a group of vehicles called a test group. A test group Start Printed Page 74259typically includes multiple vehicle lines and model types that share critical emissions-related features. The manufacturer generally selects and tests a single vehicle, typically considered “worst case” for criteria pollutant emissions, which is allowed to represent the entire test group for certification purposes. The test vehicle is the one expected to be the worst case for the emission standard at issue. Emissions from the test vehicle are assigned as the value for the entire test group. However, the compliance program in the recent GHG regulations for light-duty vehicles, which is essentially the well established CAFE compliance program, allows and may require manufacturers to perform additional testing at finer levels of vehicle models and configurations in order to get more precise model-level fuel economy and CO2 emission levels. This same approach would be applied to heavy-duty pickups and vans. Additionally, like the light-duty program, approved use of analytically derived fuel economy would be allowed to predict the fuel efficiency and CO2 levels of some vehicles in lieu of testing when deemed appropriate by the agencies. The degree to which analytically derived fuel economy would be allowed and the design of the adjustment factors would be determined by the agencies.

(b) Heavy-Duty Engines

Heavy-duty engine certification and compliance for traditional criteria pollutants has been established by EPA in its current general form since 1985. In developing a program to address GHG pollutants, it is important to build upon the infrastructure for certification and compliance that exists today. At the same time, it is necessary to develop additional tools to address compliance with GHG emissions requirements, since the proposed standard reflect control strategies that extend beyond those of traditional criteria pollutants. In so doing, the agencies are proposing use of EPA's current engine test based strategy—currently used for criteria pollutant compliance—to also measure compliance for GHG emissions. The agencies are also proposing to add new strategies to address vehicle specific designs and hardware which impact GHG emissions. The traditional engine approach would largely match the existing criteria pollutant control strategy. This would allow the basic tools for certification and compliance, which have already been developed and implemented, to be expanded for carbon dioxide, methane, and nitrous oxide. Engines with similar emissions control technology may be certified in engine families, as with criteria pollutants.

For EPA, the proposed approach for certification would follow the current process, which would require manufacturer submission of certification applications, approval of the application, and receipt of the certificate of conformity prior to introduction into commerce of any engines. EPA proposes the certificate of conformity be a single document that would be applicable for both criteria pollutants and greenhouse gas pollutants. NHTSA would assess compliance with its fuel consumption standards based on the results of the EPA GHG emissions compliance process for each engine family.

(c) Class 7 and 8 Combination Tractors and Class 2b-8 Vocational Vehicles

Currently, except for HD pickups and vans, EPA does not directly regulate exhaust emissions from heavy-duty vehicles as a complete entity. Instead, a compliance assessment of the engine is undertaken as described above. Vehicle manufacturers installing certified engines are required to do so in a manner that maintains all functionality of the emission control system. While no process exists for certifying these heavy-duty vehicles, the agencies believe that a process similar to the one we propose for use for heavy-duty engines can be applied to the vehicles.

The agencies are proposing related certification programs for heavy-duty vehicles. Manufacturers would divide their vehicles into families and submit applications to each agency for certification for each family. However, the demonstration of compliance would not require emission testing of the complete vehicle, but would instead involve a computer simulation model, GEM. This modeling tool uses a combination of manufacturer-specified and agency-defined vehicle parameters to estimate vehicle emissions and fuel consumption. This model would then be exercised over certain drive cycles. EPA and NHTSA are proposing the duty cycles over which Class 7 and 8 combination tractors would be exercised to be: 65 mile per hour steady state cruise cycle, the 55 mile per hour steady state cruise cycle, and the California ARB transient cycle. Additional details regarding these duty cycles will be addressed in Section V.D(1)(b) below. Over each duty cycle, the simulation tool would return the expected CO2 emissions, in g/ton-mile, and fuel consumption, gal/1,000 ton-mile, which would then be compared to the standards.

B. Heavy-Duty Pickup Trucks and Vans

(1) Proposed Compliance Approach

EPA and NHTSA are proposing new emission standards to control greenhouse gases (GHGs) and reduce fuel consumption from heavy-duty trucks between a gross vehicle weight rating between 8,500 and 14,000 pounds that are not already covered under the MY 2012-2016 light-duty truck and medium-duty passenger vehicle GHG standards. In this section “trucks” now refers to heavy-duty pickup trucks and vans between 8,500 and 14,000 pounds not already covered under the above light-duty rule.

First, EPA is proposing fleet average emission standards for CO2 on a gram per mile (g/mile) basis and NHTSA is proposing fuel consumption standards on a gal/100 mile basis that would apply to a manufacturer's fleet of heavy-duty trucks and vans with a GVWR from 8,500 pounds to 14,000 pounds (Class 2b and 3). CO2 is the primary pollutant resulting from the combustion of vehicular fuels, and the amount of CO2 emitted is highly correlated to the amount of fuel consumed. In addition, the EPA is proposing separate emissions standards for three other GHG pollutants: CH4, N2 O, and HFC. CH4 and N2 O emissions relate closely to the design and efficient use of emission control hardware (i.e., catalytic converters). The standards for CH4 and N2 O would be set as caps that would limit emissions increases and prevent backsliding from current emission levels. In lieu of meeting the caps, EPA is optionally proposing that manufacturer could offset any N2 O emissions or any CH4 emissions above the cap by taking steps to further reduce CO2. Separately, EPA is proposing to set standards to control the leakage of HFCs from air conditioning systems. EPA and NHTSA are requesting comment on the opportunity for manufacturers to earn credits toward the fleet-wide average CO2 and fuel consumption standards for improvements to air conditioning system efficiency that reduce the load on the engine and thereby reduce CO2 emissions and fuel consumption.

Previously, complete vehicles with a Gross Vehicle Weight Rating of 8,500-14,000 pounds could be certified according to 40 CFR part 86, subpart S. These heavy-duty chassis certified vehicles were required to pass emissions on both the Light-duty FTP and HFET (California certified only Start Printed Page 74260requirement).[197] These proposed rules would use the same testing procedures already required for heavy-duty chassis certification, namely the Light-duty FTP and the HFET but extend the requirement for chassis certification for CO2 emissions to diesel-powered vehicles. Currently, chassis certification is a gasoline requirement and a diesel option. Using the data from these two tests, EPA and NHTSA would compare the CO2 emissions and fuel consumption results against the attribute-based target. The attribute upon which the CO2 standard would be based would be a function of vehicle payload, vehicle towing capacity and two-wheel versus four-wheel drive configuration as discussed in Section II.C(1)(b) of this notice. The attribute-based standard targets would be used to determine a manufacturer fleet standard and would be subject to an average banking and trading scheme similar to the light-duty GHG rule.

This proposal would require nearly all heavy-duty trucks between 8,500 and 14,000 pounds gross vehicle weight rating that are not already covered under the light-duty truck and medium-duty passenger vehicle GHG standards to have a CO2, CH4 and N2 O values assigned to them, either from actual chassis dynamometer testing or from the results of a representative vehicle in the test group with appropriate adjustments made for differences. This requirement would apply based on whether the vehicle manufacturer sold the vehicle as a complete or nearly complete vehicle.[198] Manufacturers would be allowed to exclude vehicles they sell to secondary manufacturers without cabs (often known as rolling chassis), as well as a very small number of vehicles sold with cabs. Specifically, a manufacturer could certify up to two percent of its vehicles with complete cabs, or up to 2,000 vehicles if its total sales in this category was less than 100,000, as vocational vehicles. To the extent manufacturers are allowed to engine certify for criteria pollutant (non-GHG) requirements today, they would be allowed to continue to do so under the proposed regulations.

Because the program being proposed for heavy-duty pickup trucks and vans is so similar to the program recently adopted for light-duty trucks and codified in 40 CFR part 86, subpart S, EPA is proposing to apply most of those subpart S regulatory provisions to heavy-duty pickup trucks and vans and to not recodify them in the new part 1037. Most of the new part 1037 would not apply for heavy-duty pickup trucks and vans. How 40 CFR part 86 applies, and which provisions of the new 40 CFR part 1037 apply for heavy-duty pickup trucks and vans is described in § 1037.104.

(a) Certification Process

CAA section 203(a)(1) prohibits manufacturers from introducing a new motor vehicle into commerce unless the vehicle is covered by an EPA-issued certificate of conformity. Section 206(a)(1) of the CAA describes the requirements for EPA issuance of a certificate of conformity, based on a demonstration of compliance with the emission standards established by EPA under section 202 of the Act. The certification demonstration requires emission testing, and must be done for each model year.[199]

Under existing heavy-duty chassis certification and other EPA emission standard programs, vehicle manufacturers certify a group of vehicles called a test group. A test group typically includes multiple vehicle car lines and model types that share critical emissions-related features.[200] The manufacturer generally selects and tests one vehicle to represent the entire test group for certification purposes. The test vehicle is the one expected to be the worst case for the criteria emission standard at issue.

EPA requires the manufacturer to make a good faith demonstration in the certification application that vehicles in the test group will both (1) comply throughout their useful life within the emissions bin assigned, and (2) contribute to fleetwide compliance with the applicable emissions standards when the year is over. EPA issues a certificate for the vehicles included in the test group based on this demonstration, and includes 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 with the applicable standards.

The certification process often occurs several months prior to production and manufacturer testing may occur months before the certificate is issued. The certification process for the existing heavy-duty chassis program is an efficient way for manufacturers to conduct the needed testing well in advance of certification, and to receive certificates in a time frame which allows for the orderly production of vehicles. The use of conditions on the certificate has been an effective way to ensure that manufacturers comply throughout their useful life and meet fleet standards when the model year is complete and the accounting for the individual model sales is performed. EPA has also adopted this approach as part of its LD GHG compliance program.

EPA is proposing to similarly condition each certificate of conformity for the GHG program upon a manufacturer's good faith demonstration of compliance with the manufacturer's fleetwide average CO2 standard. The following discussion explains how EPA proposes to integrate the proposed vehicle certification program into the existing certification program.

An integrated approach with NHTSA will be undertaken to allow manufacturers a single point of entry to address certification and compliance. Vehicle manufacturers would initiate the formal certification process with their submission of application for a certificate of conformity to EPA.

(b) Certification Test Groups and Test Vehicle Selection

For heavy-duty chassis certification to the criteria emission standards, manufacturers currently as mentioned above divide their fleet into “test groups” for certification purposes. The test group is EPA's unit of certification; one certificate is issued per test group. These groupings cover vehicles with similar emission control system designs expected to have similar emissions performance (see 40 CFR 86.1827-01). The factors considered for determining test groups include Gross Vehicle Weight, combustion cycle, engine type, engine displacement, number of cylinders and cylinder arrangement, fuel type, fuel metering system, catalyst construction and precious metal composition, among others. Vehicles having these features in common are generally placed in the same test group.[201]

EPA is proposing to retain the current test group structure for heavy-duty pickups and vans in the certification requirements for CO2. At the time of Start Printed Page 74261certification, manufacturers would use the CO2 emission level from the Emission Data Vehicle as a surrogate to represent all of the models in the test group. However, following certification further testing would generally be allowed for compliance with the fleet average CO2 standard as described below. EPA's issuance of a certificate would be conditioned upon the manufacturer's subsequent model level testing and attainment of the actual fleet average, much like light-duty CAFE and GHG compliance requires. Under the current program, complete heavy-duty Otto-cycle vehicles under 14,000 pounds Gross Vehicle Weight Rating are required to chassis certify (see 40 CFR 86.1801-01(a)). The current program allows complete heavy-duty diesel vehicles under 14,000 pounds GVWR to optionally chassis certify (see 40 CFR 86.1863-07(a)). As discussed earlier, these proposed rules would now require all HD vehicles under 14,000 pounds GVWR to chassis certify except as noted in Section II.

EPA recognizes that the existing heavy-duty chassis test group criteria do not necessarily relate to CO2 emission levels. See 75 FR 25472. For instance, while some of the criteria, such as combustion cycle, engine type and displacement, and fuel metering, may have a relationship to CO2 emissions, others, such as those pertaining to the some exhaust aftertreatment features, may not. In fact, there are many vehicle design factors that impact CO2 generation and emissions but are not major factors included in EPA's test group criteria.[202] Most important among these may be vehicle weight, horsepower, aerodynamics, vehicle size, and performance features. To remedy this, EPA is considering allowing manufacturers provisions similar to the LD GHG rule that would yield more accurate CO2 estimates than only using the test group emission data vehicle CO2 emissions.

EPA believes that the current test group concept is appropriate for N2 O and CH4 because the technologies that would be employed to control N2 O and CH4 emissions may generally be the same as those used to control the criteria pollutants. However, manufacturers would determine if this approach is adequate method for N2 O and CH4 emissions compliance or if testing on additional vehicles is required to ensure the entire fleet meet applicable standards.

As just discussed, the “worst case” vehicle a manufacturer selects as the Emissions Data Vehicle to represent a test group under the existing regulations (40 CFR 86.1828-01) may not have the highest levels of CO2 in that group. For instance, there may be a heavier, more powerful configuration that would have higher CO2, but may, due to the way the catalytic converter has been matched to the engine, actually have lower NOX, CO, PM or HC emissions. Therefore, EPA is proposing to require a single Emission Data Vehicle that would represent the test group for both criteria pollutant and CO2 certification. The manufacturer would be allowed to initially apply the Emission Data Vehicle's CO2 emissions value to all models in the test group, even if other models in the test group are expected to have higher CO2 emissions. However, as a condition of the certificate, this surrogate CO2 emissions value would generally be replaced with actual, model-level CO2 values based on results from additional testing that occurs later in the model year much like the light-duty CAFE program, or through the use of approved methods for analytically derived fuel economy. This model level data would become the official certification test results (as per the conditioned certificate) and would be used to determine compliance with the fleet average. Only if the test vehicle is in fact the worst case CO2 vehicle for the test group could the manufacturer elect to apply the Emission Data Vehicle emission levels to all models in the test group for purposes of calculating fleet average emissions. Manufacturers would be unlikely to make this choice, because doing so would ignore the emissions performance of vehicle models in their fleet with lower CO2 emissions and would unnecessarily inflate their CO2 fleet average. Testing at the model level would necessarily increase testing burden beyond the minimum Emission Data Vehicle testing.

EPA requests comment regarding whether the existing heavy-duty chassis test group can adequately represent CO2 emissions for certification purposes, and whether the Emission Data Vehicle's CO2 emission level is an appropriate surrogate for all vehicles in a test group at the time of certification, given that the certificate would be conditioned upon additional model level testing occurring during the year and that the surrogate CO2 emission values would be replaced with model-level emissions data from those tests. Comments should also address EPA's desire to minimize the up-front pre-production testing burden and whether the proposed efficiencies would be balanced by the requirement to test all model types in the fleet by the conclusion of the model year in order to establish the fleet average CO2 levels.

As explained in Sections II and III, there are two standards that the manufacturer would be subject to, the fleet average standard and the in-use standard for the useful life of the vehicle. Compliance with the fleet average standard is based on production weighted averaging of the test data that applies for each model, For each model, the in-use standard is set at 10 percent higher than the level used for that model in calculating the fleet average. The certificate covers both of these standards, and the manufacturer has to demonstrate compliance with both of these standards for purposes of receiving a certificate of conformity. The certification process for the in-use standard is discussed above.

(c) Pre-Model Year (or Compliance Plan) Reporting

EPA and NHTSA are proposing that manufacturers submit a compliance plan for their entire fleet prior to the certification of any test group in a given model year. Preferably, this compliance plan would be submitted at the manufacturer's annual certification preview meeting. This preview meeting is typically held before the earliest date that the model year can begin. The earliest a model year can begin is January 2nd of the calendar year prior to the model year. This plan would include the manufacturer's estimate of its attribute-based standard, along with a demonstration of compliance with the standard based on projected model-level CO2 emissions and fuel consumption, and production estimates. This information would be similar to the information submitted to NHTSA and EPA in the pre-model year report required for CAFE compliance for light-duty vehicles. Included in the compliance plan, manufacturers seeking to take advantage of credit flexibilities would include these in their compliance demonstration. Similarly, the compliance demonstration would need to include a credible plan for addressing deficits accrued in prior model years. EPA and NHTSA would review the compliance plan for technical viability and conduct a certification preview discussion with the manufacturer. The agencies would view the compliance plan as part of the manufacturer's good faith demonstration, but understands that initial projections can vary considerably from the reality of final production and emission results. In Start Printed Page 74262addition, the compliance plan must be approved by the EPA Administrator prior to any certificate of compliance being issued. The agencies request comment on the proposal to evaluate manufacturer compliance plans prior to the beginning of model year certification.

(d) Demonstrating Compliance With the Proposed Standards

(i) CO2 and Fuel Consumption Fleet Standards

As noted, attribute-based CO2 standards result in each manufacturer having a fleet average CO2 standard unique to its heavy-duty truck fleet of GVWR between 8,500-14,000 pounds and that standard would be separate from the standard for passenger cars, light-trucks, and other heavy-duty trucks. The standards depend on those attributes corresponding to the relative capability, or “work factor”, of the vehicle models produced by that manufacturer. The proposed attributes used to determine the stringency of the CO2 standard are payload and towing capacity as described in Section II.C of this notice. Generally, fleets with a mix of vehicles with increased payloads or greater towing capacity (or utilizing four wheel drive configurations) would face numerically less stringent standards (i.e., higher CO2 grams/mile standards) than fleets consisting of less powerful vehicles. (However, the standards would be expected to be equally challenging and achieve similar percent reductions.) Although a manufacturer's fleet average standard could be estimated throughout the model year based on projected production volume of its vehicle fleet, the final compliance values would be based on the final model year production figures. A manufacturer's calculation of fleet average emissions at the end of the model year would be based on the production-weighted average emissions of each model in its fleet. The payload and towing capacity inputs used to determine manufacturer compliance with these proposed rules would be the advertised values.

The agencies propose to use the same general vehicle category definitions that are used in the current EPA HD chassis certification (See 40 CFR 86.1816-05). The new vehicle category definitions differ slightly from the EPA definitions for Heavy-duty Vehicle definitions for the existing program, as well as other EPA vehicle programs. Mainly, manufacturers would be able to test, and possibly model, more configurations of vehicles than were historically in a given test group. The existing criteria pollutant program requires the worst case configuration be tested for emissions certification. For HD chassis certification, this usually meant only testing the vehicle with the highest ALVW, road-load, and engine displacement within a given test group. This worst case configuration may only represent a small fraction of the test group production volume. By testing the worst case, albeit possibly small volume, vehicle configuration, the EPA had a reasonable expectation that all represented vehicles would pass the given emissions standards. Since CO2 standards are a fleet standard based on a combination of sales volume and work factor (i.e., payload and towing capability), it may be in a manufacturer's best interest to test multiple configurations within a given test group to more accurately estimate the fleet average CO2 emission levels and not accept the worst case vehicle test results as representative of all models. Additionally, vehicle models for which a manufacturer desires to use analytically derived fuel economy (ADFE) to estimate CO2 emission levels may need additional actual test data for vehicle models of similar but not identical configurations. The agencies are requesting comment on allowing the manufacturer to test as many configurations within a test group as the manufacturer requires in order to best represent the volumes of each configuration within that test group. The agencies are also requesting comment on using an ADFE approach similar to that used by light-duty vehicles, as explained in the light-duty vehicle/light-duty truck EPA guidance document CCD-04-06 titled “Updated Analytically Derived Fuel Economy (ADFE) Policy for 2005 MY and Later”, but expanded to a greater fraction of possible subconfigurations and using lower confidence limits than used for light-duty vehicles and light-duty trucks.

The agencies are proposing the use of ADFE similar to that allowed for light-duty vehicles in 40 CFR 600.006-08(e). This provision would allow EPA and NHTSA to accept analytical expressions to generate CO2 and fuel economy that have been approved in advance by the agencies.

For model years 2014 through 2017, or earlier if a manufacturer is certifying in order to generate early credits, EPA is proposing the equation and parameter values as expressed in Section II C or assigning a CO2 level to an individual vehicle's relevant attributes. These CO2 values would be production weighted to determine each manufacturer's fleet average. Each parameter would change on an annual basis, resulting in the annual increase in stringency. For the function used to describe the proposed standard, see Section II.C of this notice.

The GHG and fuel economy rulemaking for light-duty vehicles adopted a carbon balance methodology used historically to determine fuel consumption for the light-duty labeling and CAFE programs, whereby the carbon-related combustion products HC and CO are included on an adjusted basis in the compliance calculations, along with CO2. The resulting carbon-related exhaust emissions (CREE) of each test vehicle is calculated and it is this value, rather than simply CO2 emissions, that is used in compliance determinations. The difference between the CREE and CO2 is typically very small.

NHTSA and EPA are not proposing to adopt the CREE methodology for HD pickups and vans, and so are not proposing to adjust CO2 emissions to further account for additional HC and CO. The basis of the CREE methodology in historical labeling and CAFE programs is not relevant to HD pickups and vans, because these historical programs do not exist for HD vehicles. Furthermore, test data used in this proposal for standards-setting has not been adjusted for this effect, and so it would create an inconsistency, albeit a small one, to apply it for compliance with the numerical standards we are proposing. Finally, it would add complexity to the program with little real world benefit. We request comment on this proposed approach.

(ii) CO2 In-Use Standards and Testing

Section 202(a)(1) of the CAA requires emission standards to apply to vehicles throughout their statutory useful life. Section II.B(3)(b) of this proposal discusses in-use standards.

Currently, EPA regulations require manufacturers to conduct in-use testing as a condition of certification for heavy-duty trucks between 8,500 and 14,000 gross vehicle weight that are chassis certified. The vehicles are tested to determine the in-use levels of criteria pollutants when they are in their first and third years of service. This testing is referred to as the In-Use Verification Program, which was first implemented as part of EPA's CAP 2000 certification program (see 64 FR 23906, May 4, 1999).

EPA is requesting comment on applying the in-use program already set forth in the 2012-2016 MY light-duty vehicle rule to heavy-duty pickups and vans. The In-Use Verification Program for heavy-duty pickups and vans would follow the same general provisions of the light-duty program in regard to Start Printed Page 74263testing, vehicle selection, and reporting. See 75 FR 25474-25476.

(e) Cab-Chassis Vehicles and Complete Class 4 Vehicles

As discussed in Section I.C(2)(a), we are proposing to include most cab-chassis Class 2b and 3 vehicles in the complete HD pickup and van program. Because their numbers are relatively small, and to reduce the testing and compliance tracking burden to manufacturers, we would treat these vehicles as equivalent to the complete van or truck product they are derived from. The manufacturer would determine which complete vehicle configuration it produces most closely matches the cab-chassis product leaving its facility, and would include each of these cab-chassis vehicles in the fleet averaging calculations as though it were identical to the corresponding complete vehicle.

Any in-use testing of these vehicles would do likewise, with loading of the tested vehicle to a total weight equal to the ALVW of the corresponding complete vehicle configuration. If the secondary manufacturer had altered or replaced any vehicle components in a way that would substantially affect CO2 emissions from the tested vehicle (e.g., axle ratio has been changed for a special purpose vehicle), the vehicle manufacturer could request that EPA not test the vehicle or invalidate a test result. Secondary (finisher) manufacturers would not be subject to requirements under this provision, other than to comply with anti-tampering regulations. However, if they modify vehicle components in such a way that GHG emissions and fuel consumption are substantially affected, they become manufacturers subject to the standards under this proposal.

We realize that this approach does not capture the likely loss of aerodynamic efficiency involved in converting these vehicles from standard pickup trucks or vans to ambulances and the like, and thus it could assign them lower GHG emissions and fuel consumption than they deserve. However, we feel that this approach strikes a fair balance between the alternatives—grouping these vehicles with vocational vehicles subject only to engine standards and tire requirements, or creating a complex and burdensome program that forces vehicle manufacturers to track, and perhaps control, a plethora of vehicle configurations they currently do not manage. We request comment on this proposed provision and any suggestions for ways to improve it.

Some complete Class 4 trucks are very similar to complete Class 3 pickup truck models, including their overall vehicle architecture and use of the same basic engines. EPA and NHTSA request comment on whether these vehicles should be regulated as part of the HD pickup and van category and thereby be subject to that regulatory regime (i.e., standard stringency, chassis-based compliance for entire vehicle, credit opportunities limited to HD pickup and van subcategory, etc.), instead of as vocational vehicles as currently proposed. Comment is also requested on whether such chassis certification should be allowed as a manufacturer's option instead, and on whether vehicles so certified for GHG emissions and fuel consumption should also be allowed to certify to chassis-based criteria pollutant standards as well. Commenters are asked to address the environmental impacts of this potential change.

(2) Proposed Labeling Provisions

HD pickups and vans currently have vehicle emission control information labels showing compliance with criteria pollutant standards, similar to emission control information labels for engines. As with engines, we believe this label is sufficient.

(3) Other Certification Issues

(a) Carryover Certification Test Data

EPA's proposed certification program for vehicles allows manufacturers to carry certification test data over from one model year to the next, when no significant changes to models are made. EPA will also apply this policy to CO2, N2 O and CH4 certification test data.

(b) Compliance Fees

The CAA allows EPA to collect fees to cover the costs of issuing certificates of conformity for the classes of vehicles and engines covered by this proposal. On May 11, 2004, EPA updated its fees regulation based on a study of the costs associated with its motor vehicle and engine compliance program (69 FR 51402). At the time that cost study was conducted the current rulemaking was not considered.

At this time the extent of any added costs to EPA as a result of this proposal is not known. EPA will assess its compliance testing and other activities associated with the rule and may amend its fees regulations in the future to include any warranted new costs.

C. Heavy-Duty Engines

(1) Proposed Compliance Approach

Section 203 of the CAA requires that all motor vehicles and engines sold in the United States to carry a certificate of conformity issued by the U.S. EPA. For heavy-duty engines, the certificate specifies that the engine meets all requirements as set forth in the regulations (40 CFR part 86, subpart N, for criteria pollutants) including the requirement that the engine be compliant with emission standards. This demonstration is completed through emission testing as well as durability testing to determine the level of emissions deterioration throughout the useful life of the engine. In addition to compliance with emission standards, manufacturers are also required to warrant their products against emission defects, and demonstrate that a service network is in place to correct any such conditions. The engine manufacturer also bears responsibility in the event that an emission-related recall is necessary. Finally, the engine manufacturer is responsible for tracking and ensuring correct installation of any emission related components installed by a second party (i.e., vehicle manufacturer). EPA believes this compliance structure is also valid for administering the proposed GHG regulations for heavy-duty engines.

(a) Certification Process

In order to obtain a certificate of conformity, engine manufacturers must complete a compliance demonstration, normally consisting of test data from relatively new (low-hour) engines as well as supporting documentation, showing that their product meets emission standards and other regulatory requirements. To account for aging effects, low-hour test results are coupled with testing-based deterioration factors (DFs), which provide a ratio (or offset) of end-of-life emissions to low-hour emissions for each pollutant being measured. These factors are then applied to all subsequent low-hour test data points to predict the emissions behavior at the end of the useful life.

For purposes of this compliance demonstration and certification, engines with similar engine hardware and emission characteristics throughout their useful life may be grouped together in engine families, consistent with current criteria-pollutant certification procedures. Examples of such characteristics are the combustion cycle, aspiration method, and aftertreatment system. Under this system, the worst-case engine (“parent rating”) is selected based on having the highest fuel feed per engine stroke, and all emissions testing is completed on this model. All other models within the family (“child ratings”) are expected to have emissions at or below the parent model and therefore in compliance with emission standards. Any engine within the family Start Printed Page 74264can be subject to selective enforcement audits, in-use, confirmatory, or other compliance testing.

We are proposing to continue to use this approach for the selection of the worst-case engine (“parent rating”) for fuel consumption and GHG emissions as well. We believe this is appropriate because this worst case engine configuration would be expected to have the highest in-use fuel consumption and GHG emissions within the family. We note that lower engine ratings contained within this family would be expected to have a higher fuel consumption rate when measured over the Federal Test Procedures as expressed in terms of fuel consumption per brake horsepower hour. This higher fuel consumption rate is misleading in the context of comparing engines within a single engine family. This seeming contradiction can be most easily understood in terms of an example. For a typical engine family a top rating could be 500 horsepower with a number of lower engine ratings down to 400 horsepower or lower included within the family. When installed in identical trucks the 400 and 500 horsepower engines would be expected to operate identically when the demanded power from the engines is 400 horsepower or less. So in the case where in-use driving never included acceleration rates leading to horsepower demand greater than 400 horsepower, the two trucks with the 400 and 500 horsepower engines would give identical fuel consumption and GHG performance. When the desired vehicle acceleration rates were high enough to require more than 400 horsepower, the 500 horsepower truck would accelerate faster than the 400 horsepower truck resulting in higher average speeds and higher fuel consumption and GHG emissions measured on a per mile or per ton-mile basis. Hence, the higher rated engine family would be expected to have the highest in-use fuel consumption and CO2 emissions.

The reason that the lower engine ratings appear to have worse fuel consumption relates to our use of a brake specific work metric. The brake specific metric measures power produced from the engine and delivered to the vehicle ignoring the parasitic work internal to the engine to overcome friction and air pumping work within the engine. The fuel consumed and GHG emissions produced to overcome this internal work and to produce useful (brake) work are both measured in the test cycle but only the brake work is reflected in the calculation of the fuel consumption rate. This is desirable in the context of reducing fuel consumption as this approach rewards engine designs that minimize this internal work through better engine designs. The less work that is needed internal to the engine, the lower the fuel consumption will be. If we included the parasitic work in the calculation of the rate, we would provide no incentive to reduce internal friction and pumping losses. However, when comparing two engines within the very same family with identical internal work characteristics, this approach gives a misleading comparison between two engines as described above. This is the case because both engines have an identical fuel consumption rate to overcome internal work but different rates of brake work with the higher horsepower rating having more brake work because the test cycle is normalized to 100 percent of the engine's rated power. The fuel consumed for internal work can be thought of as a fixed offset identical between both engines. When this fixed offset is added to the fuel consumed for useful (brake) work over the cycle, it increases the overall fuel consumption (the numerator in the rate) without adding any work to the denominator. This fixed offset identical between the two engines has a bigger impact on the lower engine rating. In the extreme this can be seen easily. As the engine ratings decrease and approach zero, the brake work approaches zero and the calculated brake specific fuel consumption approaches infinity. For these reasons, we are proposing that the same selection criteria, as outlined in 40 CFR part 86, subpart N, be used to define a single engine family designation for both criteria pollutant and GHG emissions. Further, we are proposing that for fuel consumption and CO2 emissions only any selective enforcement audits, in-use, confirmatory, or other compliance testing would be limited to the parent rating for the family. This approach is being contemplated for administrative convenience and we seek comments on alternatives to address compliance testing. Consistent with the current regulations, manufacturers may electively subdivide a grouping of engines which would otherwise meet the criteria for a single family if they have evidence that the emissions are different over the useful life.

The agency utilizes a 12-digit naming convention for all mobile-source engine families (and test groups for vehicles). This convention is also shared by the California Air Resources Board which allows manufacturers to potentially use a single family name for both EPA and California ARB certification. Of the 12 digits, 9 are EPA-defined and provide identifying characteristics of the engine family. The first digit represents the model year, through use of a predefined code. For example, “A” corresponds to the 2010 model year and “B” corresponds to the 2011 model year. The 5th position corresponds to the industry sector code, which includes such examples as light-duty vehicle (V) and heavy-duty diesel engines (H). The next three digits are a unique alphanumeric code assigned to each manufacturer by EPA. The next four digits describe the displacement of the engine; the units of which are dependent on the industry segment and a decimal may be used when the displacement is in liters. For engine families with multiple displacements, the largest displacement is used for the family name. For on-highway vehicles and engines, the tenth character is reserved for use by California ARB. The final characters (including the 10th character in absence of California ARB guidance) left to the manufacturer to determine, such that the family name forms a unique identifying characteristic of the engine family.

This convention is well understood by the regulated industries, provides sufficient detail, and is flexible enough to be used across a wide spectrum of vehicle and engine categories. In addition, the current harmonization with other regulatory bodies reduces complications for affected manufacturers. For these reasons, we are not proposing any major changes to this naming convention for this proposal. There may be additional categories defined for the 5th character to address heavy-duty vehicle test groups, however that will be discussed later.

As with criteria pollutant standards, the heavy-duty diesel regulatory category is subdivided into three regulatory subcategories, depending on the GVW of the vehicle in which the engine will be used. These regulatory subcategories are defined as light-heavy-duty (LHD) diesel, medium heavy-duty (MHD) diesel, and heavy heavy-duty (HHD) diesel engines. All heavy-duty gasoline engines are grouped into a single subcategory. Each of these regulatory subcategories are expected to be in service for varying amounts of time, so they each carry different regulatory useful lives. For this reason, expectations for demonstrating useful life compliance differ by subcategory, particularly as related to deterioration factors.

Light heavy-duty diesel engines (and all gasoline heavy-duty engines) have Start Printed Page 74265the same regulatory useful life as a light-duty vehicle (110,000 miles), which is significantly shorter than the other heavy-duty regulatory subcategories. Therefore, we believe it is appropriate to maintain commonality with the light-duty GHG rule. During the light-duty GHG rulemaking, the conclusion was reached that no significant deterioration would occur over the useful life. Therefore, EPA is proposing to specify that manufacturers would use assigned DFs for CO2 and the values would be zero (for additive DFs) and one (for multiplicative DFs). EPA is interested in data that addresses this issue.

For the medium heavy-duty and heavy heavy-duty diesel engine segments, the regulatory useful lives are significantly longer (185,000 and 435,000 miles, respectively). For this reason, the agency is not convinced that engine/aftertreatment wear will not have a negative impact on GHG emissions. To address useful life compliance for MHD and HHD diesel engines certified to GHG standards, we believe the criteria pollutant approach for developing DFs is appropriate. Using CO2 as an example, many of the engine deterioration concerns previously identified will affect CO2 emissions. Reduced compression, as a result of wear, will cause higher fuel consumption and increase CO2 production. In addition, as aftertreatment devices age (primarily particulate traps), regeneration events may become more frequent and take longer to complete. Since regeneration commonly requires an increase in fuel rate, CO2 emissions would likely increase as well. Finally, any changes in EGR levels will affect heat release rates, peak combustion temperatures, and completeness of combustion. Since these factors could reasonably be expected to change fuel consumption, CO2 emissions would be expected to change accordingly.

HHD diesel engines may also require some degree of aftertreatment maintenance throughout their useful life. For example, one major heavy-duty engine manufacturer specifies that their diesel particulate filters be removed and cleaned at intervals between 200,000 and 400,000 miles, depending on the severity of service. Another major engine manufacturer requires servicing diesel particulate filters at 300,000 miles. This maintenance or lack thereof if service is neglected, could have serious negative implications to CO2 emissions. In addition, there may be emissions-related warranty implications for manufacturers to ensure that if rebuilding or specific emissions related maintenance is necessary, it will occur at the prescribed intervals. Therefore, it is imperative that manufacturers are detailed in their maintenance instructions. The agency currently seeks public comment on how to properly address this issue.

Lean-NOX aftertreatment devices may also facilitate GHG reductions by allowing engines to run with higher engine-out NOX levels in exchange for more efficient calibrations. In most cases, these aftertreatment devices require a consumable reductant, such as diesel exhaust fluid, which requires periodic maintenance by the vehicle operator. Without such maintenance, the emission control system may be compromised and compliance with emission standards may be jeopardized. Such maintenance is considered to be critical emission related maintenance and manufacturers must therefore demonstrate that it is likely to be completed at the required intervals. One example of such a demonstration is an engine power de-rate strategy that will limit engine power or vehicle speed in absence of this required maintenance.

If the manufacturer determines that maintenance is necessary on critical emission-related components within the useful life period, they must have a reasonable basis for ensuring that this maintenance will be completed as scheduled. This includes any adjustment, cleaning, repair, or replacement of critical emission-related components. Typically, the agency has only allowed manufacturers to schedule such maintenance if the manufacturer can demonstrate that the maintenance is reasonably likely to be done at the recommended intervals. This demonstration may be in the form of survey data showing at least 80 percent of in-use engines get the prescribed maintenance at the correct intervals. Another possibility is to provide the maintenance free of charge. We see no reason to depart from this approach for GHG-related critical emission-related components; however the agency welco