2011 Chevrolet Impala Owner's Manual - Page 314

10-58 Vehicle Care Vehicle Storage Tires age when stored normally mounted on a parked vehicle. Park a vehicle that will be stored for at least a month in a cool, dry, clean area away from direct sunlight to slow aging. This area should be free of grease, gasoline, or other substances that can deteriorate rubber. Parking for an extended period can cause flat spots on the tires that may result in vibrations while driving. When storing a vehicle for at least a month, remove the tires or raise the vehicle to reduce the weight from the tires. See Tire Inspection on page 10‑56 and Tire Rotation on page 10‑56 for more information. The rubber in tires ages over time. This also applies for the spare tire, if the vehicle has one, even if it is never used. Multiple conditions including temperatures, loading conditions, and inflation pressure maintenance affect how fast aging takes place. Tires will typically need to be replaced due to wear before they may need to be replaced due to age. Consult the tire manufacturer for more information on when tires should be replaced. Buying New Tires GM has developed and matched specific tires for the vehicle. The original equipment tires installed on the 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, the vehicle will continue to have tires that are designed to give the same performance and vehicle safety, during normal use, as the original tires.