International Truck and Engine Corporation (International) of Fort Wayne, Indiana, has determined that approximately 801 vehicles produced from January 1, 1986, through January 16, 2001, do not comply with paragraph S5.1 of Federal Motor Vehicle Safety Standard (FMVSS) No. 120, “Tire Selection and Rims for Motor Vehicles other than Passenger Cars.” Pursuant to 49 U.S.C. 30118(d) and 30120(h), International petitioned for a determination that this noncompliance is inconsequential to motor vehicle safety and filed an appropriate report pursuant to 49 CFR part 573, “Defect and Noncompliance Reports.”

Notice of receipt of the application was published on August 24, 2001, with a 30-day comment period (66 FR 44663). ( printed page 19802) NHTSA received no comments on this application.

International built trucks, truck tractors, and buses with 295/75R22.5 tires mounted on 7.50 inch wide rims. Paragraph S5.1.1 of FMVSS No. 120 requires that vehicles be equipped with rims that are listed as suitable for use with the tires that are mounted on them in accordance with paragraph S5.1 of FMVSS No. 119, “New Pneumatic Tires for Vehicles other than Passenger Cars.” Paragraph S 5.1 of FMVSS No. 119 refers to the listing of rims that may be used with various tires in the “Tire and Rim Association, Inc. (T&RA) Yearbook”, or another designated publication. According to T&RA, the approved rim widths for 295/75/R22.5 tires are between 8.25 and 9.00 inches.

The T&RA approved rim widths are based on an engineering guideline stating that the rim width should be 70 to 80 percent of the tire section width. International cited a statement in the T&RA Yearbook that the effect of using rims of different than design rim width is to change the tire section width by 0.1 inch for each 0.25 inch change in rim width. The section width for the 295/75R22.5 tires is 11.43 inches when mounted on an 8.25 inch wide rim. The tire section width is reduced to 11.13 inches when the tires are mounted on a 7.5 inch wide rim, resulting in a rim width that is about 67 percent or the tire section width. Theoretically, a 7.9 inch wide rim, which is not available (not in production), would be required for the subject tires to meet the T&RA engineering guideline that the rim width be 70 percent of the tire width. International concluded, therefore, that the 7.5 inch wide rim is 95 percent as wide as the 7.9 inch wide rim that would be required for 295/75R22.5 size tires under the 70 percent guideline (but not the width specified in the Year Book).

International stated that the noncompliant mounting of the 295/75R22.5 tires on the 7.5 inch wide rims is inconsequential to motor vehicle safety for the following reasons:

1. International customers have operated vehicles of various model types for 15 years with this combination of tire and rim, with no reported problems.

2. International has corrected its tire wheel assembly instruction charts and as of 1/17/01, it will no longer produce this non-compliant tire and rim combination.

3. Many of these vehicles probably have gone through several tire replacement cycles without reported problems.

The agency believes that the true measure of inconsequentiality to motor vehicle safety in this case is the effect of the noncompliance on the safety of the vehicles on which the noncompliant tire and rim combination is mounted. According to International, the 801 heavy duty trucks, truck tractors, and buses with this FMVSS No. 120 noncompliance are not likely to develop safety consequences. International has recognized that, compared to tires mounted on correctly sized rims, the tires mounted on rims that are too narrow may experience a decrease in sidewall durability, and may also experience higher treadwear for tires mounted on the steering axle. Although International asserted that these differences in tire wear are small and not likely to reduce the safety performance of the vehicles, the agency does not agree.

The purpose of this section of FMVSS No. 120 is to ensure that trucks and buses are equipped with rims and tires that are properly matched. The failure of International to meet the tire and rim matching requirements is a serious violation of the design requirements of the standard. Granting of this petition would establish a precedent that the mismatching of tires and rims is acceptable and, therefore, would undermine the enforceability of these requirements.

In consideration of the foregoing, NHTSA has decided that the applicant has not met its burden of persuasion, and that the noncompliance may have an adverse effect on the safety of these vehicles. Accordingly, International's application is denied and the company must provide notification of the noncompliance, as required by 49 U.S.C. 30118. Also, International must provide a free remedy of the noncompliance for all vehicles bought by the first purchaser ten calendar years or less before notice is given, as required by 49 U.S.C. 30120(g).