2012 Cadillac SRX Owner Manual - Page 392
2012 Cadillac SRX Manual
Page 392 highlights
10-52 Vehicle Care (F) Tire Size: A combination of letters and numbers define a tire's width, height, aspect ratio, construction type, and service description. The letter T as the first character in the tire size means the tire is for temporary use only. (G) TPC Spec (Tire Performance Criteria Specification): Original equipment tires designed to GM's specific tire performance criteria have a TPC specification code molded onto the sidewall. GM's TPC specifications meet or exceed all federal safety guidelines. Tire Designations Tire Size The following is an example of a typical passenger vehicle tire size. (C) Aspect Ratio: A twodigit number that indicates the tire heighttowidth measurements. For example, if the tire size aspect ratio is 60, as shown in item C of the illustration, it would mean that the tire's sidewall is 60 percent as high as it is wide. (D) Construction Code: A letter code is used to indicate the type of ply construction in the tire. The letter R means radial ply construction; the letter D means diagonal or bias ply construction; and the letter B means beltedbias ply construction. (E) Rim Diameter : Diameter of the wheel in inches. (A) Passenger (PMetric) Tire: The United States version of a metric tire sizing system. The letter P as the first character in the tire size means a passenger vehicle tire engineered to standards set by the U.S. Tire and Rim Association. (B) Tire Width: The threedigit number indicates the tire section width in millimeters from sidewall to sidewall.