2008 GMC Sierra 1500 Pickup Owner's Manual - Page 373

(C) Dual Tire Maximum Load: Maximum load that can be carried and the maximum pressure needed to support that load when used in a dual configuration. For information on recommended tire pressure see Inflation - Tire Pressure on page 5-65 and Loading Your Vehicle on page 4-34. (D) DOT (Department of Transportation): The Department of Transportation (DOT) code indicates that the tire is in compliance with the U.S. Department of Transportation Motor Vehicle Safety Standards. (E) Tire Identification Number (TIN): The letters and numbers following DOT code are 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. (F) Tire Ply Material: The type of cord and number of plies in the sidewall and under the tread. (G) Single Tire Maximum Load: Maximum load that can be carried and the maximum pressure needed to support that load when used as a single. For information on recommended tire pressure see Inflation - Tire Pressure on page 5-65 and Loading Your Vehicle on page 4-34. Tire Size The following examples show the different parts of a tire size. Passenger (P-Metric) Tire Light Truck (LT-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. 5-61