2010 Chevrolet Avalanche Owner's Manual - Page 472
2010 Chevrolet Avalanche Manual
Page 472 highlights
Tire Size The following examples show the different parts of a tire size. (C) Aspect Ratio : A two‐digit number that indicates the tire height‐to‐width measurements. For example, if the tire size aspect ratio is 75, as shown in item C of the tire illustration, it would mean that the tire's sidewall is 75 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. (E) Rim Diameter : Diameter of the wheel in inches. (F) Service Description : These characters represent the load index and speed rating of the tire. The load index represents the load carry capacity a tire is certified to carry. The speed rating is the maximum speed a tire is certified to carry a load. Passenger (P‐Metric) Tire (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. 6-58