1993 Oldsmobile 88 Owner's Manual - Page 251

Sewice & Appearance Care Buying New Tires 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 (bias Idormation label. The tires installed on bias-belted or radial) as your original your vehicle whenit was new had a Tire tires. Performance Criteria Specification (TPC Spec) numberon 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 thatare designed to give proper endurance, handling, speed rating, traction, ride and other things during normal service your vehicle. on If your tires have an all-season tread design, the TPC number willfollowed be by a "MS" (for mud and snow). If you ever replace your tires with those not having aTPC Spec number, make 250 Unifomt Xire Quality Grading The following information relates the to system developed by theU i e States ntd National Highway Traffic Safety Administration which grades tires by treadwear, traction and temperature performance. (This applies only to vehicles sold in the United States.) Tmaciwear The treadwear grade is a comparative rating based on the wear rate of tire the when tested under controlled conditions on a specified government test course. 5 For example, a tire graded 1 0 would (1%) times as well wear one and a half on thegovernment course as a tire graded 100. The relative performance of tires depends upon the actual conditions