2010 Buick LaCrosse Owner's Manual - Page 344

9-64 Vehicle Care The rubber in tires degrades over time. This is also true for the spare tire, if the vehicle has one, even if it is not being used. Multiple conditions affect how fast this aging takes place, including temperatures, loading conditions, and inflation pressure maintenance. With proper care and maintenance tires typically wear out before they degrade due to age. If you are unsure about the need to replace the tires as they get older, consult the tire manufacturer for more information. The vehicle needs new tires if any of the following statements are true: . Buying New Tires GM has developed and matched specific tires for your vehicle. The original equipment tires installed on your vehicle, when it was new, were designed to meet General Motors Tire Performance Criteria Specification (TPC Spec) system rating. If you need replacement tires, GM strongly recommends that you get tires with the same TPC Spec rating. This way, your vehicle will continue to have tires that are designed to give the same performance and vehicle safety, during normal use, as the original tires. You can see the indicators at three or more places around the tire. You can see cord or fabric showing through the tire's rubber. The tread or sidewall is cracked, cut, or snagged deep enough to show cord or fabric. The tire has a bump, bulge, or split. The tire has a puncture, cut, or other damage that cannot be repaired well because of the size or location of the damage. . . . .