2007 Cadillac STS Owner's Manual - Page 425

(B) Tire Ply Material: The type of cord and number of plies in the sidewall and under the tread. (C) Tire Identification Number (TIN): The letters and numbers following the DOT (Department of Transportation) code is the Tire Identification Number (TIN). The TIN shows the manufacturer and plant code, tire size, and date the tire was manufactured. The TIN is molded onto both sides of the tire, although only one side may have the date of manufacture. (D) Maximum Cold Inflation Load Limit: Maximum load that can be carried and the maximum pressure needed to support that load. (E) Tire Inflation: The temporary use tire or compact spare tire should be inflated to 60 psi (420 kPa). For more information on tire pressure and inflation see Inflation - Tire Pressure on page 431. (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 Size The following illustration shows an example of a typical passenger vehicle tire size. (A) Passenger (P-Metric) 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 three-digit number indicates the tire section width in millimeters from sidewall to sidewall. 425