2013 Chevrolet Volt Owner Manual - Page 291

Vehicle Care (2) 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. (3) 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. DOT Tire Date of Manufacture: The last four digits of the TIN indicate the tire manufactured date. The first two digits represent the week (01-52) and the last two digits, the year. For example, the third week of the year 2010 would have a four-digit DOT date of 0310. (4) Tire Identification Number (TIN): The letters and numbers following the 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. (5) Tire Ply Material : The type of cord and number of plies in the sidewall and under the tread. (6) Uniform Tire Quality Grading (UTQG): Tire manufacturers are required to grade tires based on three performance factors: treadwear, traction, and temperature 10-43 resistance. For more information see Uniform Tire Quality Grading on page 10‑56. (7) Maximum Cold Inflation Load Limit: Maximum load that can be carried and the maximum pressure needed to support that load. Tire Designations Tire Size The following is an example of a typical passenger vehicle tire size. (1) Passenger (P-Metric) Tire: The United States version of a metric tire sizing system. The letter P as the first character in