1994 Oldsmobile Silhouette Owner's Manual - Page 211

Buying New Tires To find out whatkind and size of tires you need, look at the Certification/Tire label. The tiresinstalled on your vehicle when it was new had a Tire Performance Criteria Specification (TPC Spec) number oneach tire's sidewall. When you get new tires, get ones with that same TPC Spec number. That way, your vehicle willcontinue tohave 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 allseason treaddesign, the TPC number will be followedby a "MS" (for mud and snow). If you ever replace your tires with those not having a TPC Spec number, make sure they are the same load range, size, speed rating and construction type (bias, bias-belted or radial) as your original tires. i TREAD WEAR INDICATORS When It's Time for New Tires One way to tell when it's time for new tires is to check the treadwear indicators, whichwill appear whenyou. tires haveonly 2/32 inch (1.6 mm) or less of tread remaining. You need anew tire if: You can seethe indicators at three or more places around the tire. You can seecord or fabric showing through thetire's rubber. The tread or sidewall is cracked, cut or snagged deep enoughto show cord or fabric. The tire has a bump, bulge or split. The tire has a puncture, cut, other or damage that can't be repaired well because of the size or locationof the damage. Iz 209