1996 Buick Century Owner's Manual

I\ CAUTION:Mixing tires could cause you to lose control whiledriving. If you mix tires of different sizes or types(radial and bias-belted tires), the vehicle may nothandle properly, and you could have a crash.Using tires of different sizes may also causedamage to your vehicle. Be sure to use the samesize and type tires on all wheels.It’s all right to drive with your compact spare,though. It was developed for use on your vehicle.Uniform Tire Quality GradingThe following information relates to the systemdeveloped by the United States National HighwayTraffic Safety Administration, which grades tires bytreadwear, traction and temperature performance. (Thisapplies only to vehicles sold in the United States.) Thegrades are molded on the sidewalls of most passengercar tires. The Uniform Tire Quality Grading system doesnot apply to deep tread, winter-type snow tires,space-saver or temporary use spare tires, tires withnominal rim diameters of 10 to 12 inches (25 to 30 cm),or to some limited-production tires.While the tires available on General Motors passengercars and light trucks may vary with respect to thesegrades, they must also conform to Federal safetyrequirements and additional General Motors TirePerformance Criteria (TPC) standards.6-42