2013 Chevrolet Impala Owner Manual - Page 257

Vehicle Care (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 420 kPa (60 psi). For more information on tire pressure and inflation see Tire Pressure on page 10‑38. (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. 10-35 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. (C) Aspect Ratio: A two‐digit number that indicates the tire height‐to‐width 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 belted‐bias ply construction. Tire Designations Tire Size The following is 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