Buying New TiresGM has developed and matched specific tires for yourvehicle. The original equipment tires installed onyour vehicle, when it was new, were designed to meetGeneral Motors Tire Performance Criteria Specification(TPC spec) system rating. If you need replacementtires, GM strongly recommends that you get tires withthe same TPC Spec rating. This way, your vehiclewill continue to have tires that are designed to give thesame performance and vehicle safety, during normaluse, as the original tires.GM’s exclusive TPC Spec system considers over adozen critical specifications that impact the overallperformance of your vehicle, including brake systemperformance, ride and handling, traction control, and tirepressure monitoring performance. GM’s TPC Specnumber is molded onto the tire’s sidewall near the tiresize. If the tires have an all-season tread design, the TPCspec number will be followed by an MS for mud andsnow. See Tire Sidewall Labeling on page 5-55 foradditional information.GM recommends replacing tires in sets of four. This isbecause uniform tread depth on all tires will help keepyour vehicle performing most like it did when the tireswere new. Replacing less than a full set of tires can affectthe braking and handling performance of your vehicle.See Tire Inspection and Rotation on page 5-68 forinformation on proper tire rotation.{CAUTION:Mixing tires could cause you to lose controlwhile driving. If you mix tires of different sizes,brands, or types (radial and bias-belted tires),the vehicle might not handle properly, and youcould have a crash. Using tires of differentsizes, brands, or types could also causedamage to your vehicle. Be sure to use thesame size, brand, and type tires on all wheels.Your vehicle may have a different size sparethan the road tires (those originally installed onyour vehicle). When new, your vehicle includeda spare tire and wheel assembly with a similaroverall diameter as your vehicle’s road tires andwheels, so it is all right to drive on it. Becausethis spare was developed for use on yourvehicle, it will not affect vehicle handling.5-71
