2007 Chevrolet Cobalt Owner's Manual - Page 336
2007 Chevrolet Cobalt Manual
Page 336 highlights
Tire Sidewall Labeling Useful information about a tire is molded into its sidewall. The examples below show a typical passenger vehicle tire and a compact spare tire sidewall. (A) Tire Size: The tire size is a combination of letters and numbers used to define a particular tire's width, height, aspect ratio, construction type and service description. See the "Tire Size" illustration later in this section for more detail. (B) 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. If your vehicle has 205/55R16 size tires, they meet the GM TPC Spec rating, but the TPC Spec code has not been molded onto the tire's sidewall. (C) 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. Passenger (P-Metric) Tire Example 336