Interpretation ID: aiam2474
House of Representatives
Washington
D.C. 20515;
Dear Mr. Quie: This is in reply to your letter of December 15, 1976, regarding complaint by Mr. Russ Fink, that tires marked within a certain size classification are not uniform.; Mr. Fink's letter does not report any actual tire dimensions and doe not fully explain the age of his tires, the amount of treadwear, the type of tread pattern, inflation pressures, and the width of the rims when he was making his measurements. All of these factors have an effect on tire size matching, and must be considered in making dimensional comparisons.; Contrary to Mr. Fink's claim, tire manufacturing is carefull controlled to meed rigid dimensional requirements. These requirements are a part of our Federal Motor Vehicle Safety Standards (FMVSS) No. 109 for new passenger car tires, No. 119 for other new motor vehicle tires, and No. 117 for retreaded passenger car tires. A copy of each is enclosed . Every effort is made in our standards enforcement program to assure that manufacturers and retreaders comply with the specified dimensional requirements.; Referring to the tables in Appendix AS of FMVSS No. 109, Mr. Fink ca see that there are differences is specifications for the three tires he mentions:; Tire Rim Max. Load Section Min. Size Size Width at 24 psi Width Facto H78-15 6'' 1450 8.55 36.50 7.60-15 5-1/2'' 1450 7.90 36.05 8.55-15 6'' 1510 8.45 36.57; In purchasing new or retreaded tires from a tire dealer, consumers ar entitled to dimensions held within specified tolerances, and when tires are found to exceed these tolerances we would appreciate being notified so that we may initiate investigation.; Sincerely, John W. Snow, Administrator