1998 Pontiac Grand Prix Owner's Manual - Page 323
1998 Pontiac Grand Prix Manual
Page 323 highlights
Buying New Tires To find out what kind and size tires you need, look at of the Tire-Loading Information label. The tires installedon your vehicle whenit was new had a Tire Performance Criteria Specification (TPC Spec) number on each tire's sidewall. When you get new tires, get ones with that same Spec number. That way TPC your vehicle will continue to have tires that are designed to give proper endurance, handling, speed rating, traction, ride and other things during normal service on your vehicle.If your tires have an all-season tread design, the TPC number will be followed by"MS" an (for mud and snow). If you ever replace your tires with those not having a TPC Spec number, make sure they are the same size, load range, speed rating and construction type (bias, bias-belted or radial) as your original tires. I A CAUTION: Mixing tires could cause you to lose control while or driving. If you mix tires of different sizes types (radial andbias-belted tires), the vehicle may not handle properly, and you could havea crash. Using tires of different sizes may also cause damage to your vehicle. Be sure touse the same size and type tires on wheels. all It's all right to drive with your compact spare, though. It was developed for use on your vehicle. A CAUTION: If you usebias-ply tires on your vehicle, the wheel rim flanges could develop cracksafter many miles of driving. A tire and/or wheel could fail suddenly, causing crash. Use only radial-ply a tires with the wheels on your vehicle. 6-48