1993 Cadillac Seville Owner's Manual - Page 325

Buying New Tires To find out what kind and size of tires you need, look at theTire-Loading Information 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 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 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 thesame size, load range,speed rating and construction type (bias, bias-belted or radial) as your original tires. A CAUTION: Mixing tires could causeyou to lose control while driving.If you mix tires of different sizesor types (radial and bias-belted tires), the vehicle may not handle properly, you could havea and crash. Be sure to usethe same sizeand type tires on all four wheels. It's all right to drive with your compact spare, though. It was developed for use your vehicle. on Uniform Tire Quality Grading The following information relates to the system developedby the United States National Highway Traffic Safety Administration which grades tires by treadwear, traction and temperature performance. (This applies only to vehicles soldin the United States.) 311