1993 Pontiac Grand Prix Owner's Manual - Page 258

When It's Time forNew Tires One way to tell when it's time for new tires isto check the treadwear indicators, which will appear when your tires have only 2/32 inch (1.6mm) or less of tread remaining. You need a newtire if: You can see the indicators at three places around the tire. You can see cord or fabric showing through the tire's rubber. The tread or sidewall is cracked, cut or snagged deep enough show cord to or fabric. The tire has a bump, bulge or split. The tire has a puncture, cut, or other damage that can't be repaired well because of the size or locationof the damage. Buying New Tires If you ever replace your tires with those not having aTPC Spec number, make To find out what kind and size of tires sure they are the same size, load range, you need, look at the Tire-Loading speed rating and construction type Information label. The tires installed on (bias, bias-belted or radial) as your your vehiclewhen itwas new had a Tire original tires. Performance Criteria Specification (TPC Spec) number on each tire's sidewall. When you get new tires, get ' 1 Mixing tires could cause you ones with that same TPC Spec number. A to lose control while driving. That way, your vehicle will continue to If you mix tires of different sizes or have tires thatare designed to give types (radial and bias-belted tires), proper endurance, handling, speed the vehicle may not handle rating, traction, ride and otherthings properly, and you could have a during normal serviceon your vehicle. crash. Be sure to use the same size If your tires have an all-season tread and type tires on all wheels. It's all design, the TPC number will be right to drive with yourcompact followed by a "MS" (for mud and spare, though. It was developed for snow). limited use on vour vehicle. 257 r = a