2004 Cadillac XLR Owner's Manual - Page 275

A. B. C. D. E. F. G. Tire Size Tire Performance Criteria Specification (TPC Spec) Department of Transportation (DOT) Tire Identification Number (TIN) Tire Ply Material Uniform Tire Quality Grading (UTQG) Maximum Cold Inflation Load Limit (A) Tire Size: The tire size code 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) Tire Performance Criteria Specification (TPC Spec): 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. (C) Department of Transportation (DOT): The Department of Transportation (DOT) code indicates that the tire is in compliance with the U.S. Department of Transportation Motor Vehicle Safety Standards. 5-51