2006 Cadillac STS-V Owner's Manual - Page 385

Your GM dealer can order these tires by part number. This way, your vehicle will continue to give the proper endurance, handling, traction, and ride as the original tires. Winter tires with the same speed rating as your original equipment tires may not be available for H, V, W, Y and ZR speed rated tires. If you choose snow tires with a lower speed rating, never exceed the tire's maximum speed capability. CAUTION: (Continued) Be sure to use the correct size, brand, and type of tires on all wheels. It is all right to drive with your vehicle's compact spare temporarily, it was developed for use on your vehicle. See Compact Spare Tire (STS Only) on page 5-93. {CAUTION: Mixing tires could cause you to lose control while driving. If you mix tires of different sizes (other than those originally installed on your vehicle), brands, or types (radial and bias-belted tires), the vehicle may not handle properly, and you could have a crash. Using tires of different sizes (other than those originally installed on your vehicle), brands, or types may also cause damage to your vehicle. CAUTION: (Continued) {CAUTION: If you use bias-ply tires on your vehicle, the wheel rim flanges could develop cracks after many miles of driving. A tire and/or wheel could fail suddenly, causing a crash. Use only radial-ply tires with the wheels on your vehicle. If you must replace your vehicle's tires with those that do not have a TPC Spec number, make sure they are the same size, load range, speed rating, and construction type (radial and bias-belted tires) as your vehicle's original tires. 5-73