2004 Pontiac Vibe Owner's Manual - Page 274
2004 Pontiac Vibe Manual
Page 274 highlights
Tire Size The following illustration shows an example of a typical passenger car tire size. 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. Tire Width: The three-digit number indicates the tire section width in millimeters from sidewall to sidewall. Aspect Ratio: A two-digit number that indicates the tire height-to-width measurements. For example, if the tire size aspect ratio is "70," as shown in item "C" of the illustration, it would mean that the tire's sidewall is 70% as high as it is wide. Belt Rating: 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. Rim Diameter: Diameter of the wheel in inches. Load Range: The load range represents the load carry capacity a tire is certified to carry. Speed Rating: The maximum speed that a tire is certified to carry a load. Speed ratings range from "A" to "Z". A. B. C. D. E. F. G. Passenger (P-Metric) Tire Tire Width Aspect Ratio Belt Rating Rim Diameter Load Range Speed Rating 5-64