1998 Chevrolet Astro Owner's Manual - Page 308

Buying New Tires To find out what kind and of tires you need, look at size the CertificationRire label. The tires installed on your vehicle when it 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 TPC Spec number. That way your vehicle willcontinue to have tires that are designed to giveproper 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 an "MS" (for mud andsnow). If you ever replace your tires withthose 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 contrc while driving. If you mix tires of different sizes or types (radial and bias-belted tires), the vehicle may not handle properly, andyou could have a crash. Using tires of different sizes may also cause damage to your vehicle. Be sure touse the same size and type tireson all wheels. It's all right to drive with your compact spare, though. It was developed for use your vehicle. on --- If you use bias-ply tires on your vehil ,the wheel rim flanges could develop cracks after many miles of driving. A tire and/orwheel could fail suddenly, causing crash. Use only radial-ply a tires with the wheels on your vehicle. 6-46