2006 Chevrolet Cobalt Owner's Manual - Page 305
2006 Chevrolet Cobalt Manual
Page 305 highlights
Tire size 205/55R16 91 H, used on some vehicles, meets the General Motors Tire Performance Criteria Specification (TPC Spec) rating, but the TPC Spec code has not been molded onto the tire's sidewall. If your vehicle has these tires, and you need to replace them, you can still get these TPC Spec rated tires by asking your GM dealer. 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 winter tires with a lower speed rating, never exceed the tire's maximum speed capability. {CAUTION: Mixing tires could cause you to lose control while driving. If you mix tires of different sizes, 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, brands, or types may also cause damage to your vehicle. Be sure to use the correct size, brand, and type of tires on all wheels. It is all right to drive with your compact spare temporarily, as it was developed for use on your vehicle. See Compact Spare Tire on page 5-83. 5-65