Interpretation ID: aiam2436
Commander
Engineering Section
Department of California Highway Patrol
P.O. Box 898
Sacramento
California 95804;
Dear Mr. Commander Heath: This responds to your September 16, 1976, question whether any Federa regulation required that the maximum load rating assigned to a passenger car tire be reduced by approximately 10 percent in calculating its maximum load rating for use on a multipurpose passenger vehicle (MPV), truck, or bus.; The answer to your question is yes. Standard No. 120, *Tire Selectio and Rims for Motor Vehicles Other than Passenger Cars*, became effective September 1, 1976, and provides for the reduced maximum load rating you describe. Section S5.1.2 of the standard provides in part that '[w]hen a tire listed in [the passenger car tire standard] is installed on a multipurpose passenger vehicle, truck, bus, or trailer, the tire's load rating shall be reduced by dividing by 1.10 before calculating the sum [that must at least equal the axle system's gross axle weight rating].' A copy of the standard, with subsequent amendments, is enclosed for your information.; Sincerely, Frank A. Berndt, Acting Chief Counsel