Tire Sidewall LabelingUseful information about a tire is molded into thesidewall. The following illustration is an exampleof a typical P-Metric tire sidewall.(A) Tire Size: The tire size code is a combinationof letters and numbers used to define a particulartire’s width, height, aspect ratio, constructiontype, and service description. See the “Tire Size”illustration later in this section for more detail.(B) TPC Spec (Tire Performance CriteriaSpecification): Original equipment tires designedto GM’s specific tire performance criteria havea TPC specification code molded onto the sidewall.GM’s TPC specifications meet or exceed allfederal safety guidelines.(C) DOT (Department of Transportation):The Department of Transportation (DOT) codeindicates that the tire is in compliance with theU.S. Department of Transportation Motor VehicleSafety Standards.(D) Tire Identification Number (TIN): The lettersand numbers following DOT code are the TireIdentification Number (TIN). The TIN showsthe manufacturer and plant code, tire size, anddate the tire was manufactured. The TIN is moldedonto both sides of the tire, although only oneside may have the date of manufacture.(E) Tire Ply Material: The type of cord and numberof plies in the sidewall and under the tread.(F) Uniform Tire Quality Grading (UTQG):Tire manufacturers are required to gradetires based on three performance factors:treadwear, traction, and temperature resistance.For more information, see Uniform Tire QualityGrading on page 6-73.Passenger (P-Metric) Tire6-57
