1996 Pontiac Firebird Owner's Manual - Page 290

Buying New Tires To find out what kind and size tires you need, look at of the Tire-Loading Information label. it was The tires installed on your vehicle when 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 TPC Spec number. That way your vehicle will continue to have tires that are designed to give proper endurance, handling, speed rating, traction, ride and other things during normal serviceon your vehicle.If your tires have an all-season tread design, the TPC number be followedby an "MS" will (for mud and snow). If you ever replace your tires with those not having a TPC Spec number, make sure they are same size, the load range, speed rating and construction type (bias, bias-belted or radial) as your original tires. I A. > Mixing tires could cause you lose control while to driving. If you mix tires of different sizes or types (radial and bias-belted tires),the vehicle maynot handle properly, and you could have a crash. Using tires of different sizes may also cause damage toyour vehicle. Besure to use the same size and type tires on all wheels. It's all right to drive with your compact spare, though. It was developed for use onyour vehicle. .. . -. I ' , . 6-49