1993 Buick Century Owner's Manual - Page 256

When It's Time for New Tires One way to tell when it's time for newtires is to check the treadwear indicators, which will appear when your tires have only 2/32 inch (1.6 mm) or less of tread remaining. You need a new tire if Buying New Tires To find out what kind and size tires you need, lookat of the Tire-Loading Information label. The tires installed on your vehicle when itnew .had a was Tire Performance Criteria Specification (TPC Spec) number on each tire's sidewall. When you get new tires, get ones with that same TPC number. That way, Spec 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 a "MS"(for mud by and snow). i You can see the indicators at threeplaces around ther . te i You can see cordor fabric showing through If you ever replace your tires with those not having a the tire's rubber. TPC Spec number, make sure they are the same size, load range, speed rating and construction type (bias, The tread or sidewall is cracked, cut snagged deep or bias-belted or radial) as your original tires. enough to show cordor fabric. The tirehas a bump, bulgeor split. The tirehas a puncture,cut, or other damage that can't be repaired well because of the size locationof the or damage. 254