Factors such as maintenance, temperatures, driving speeds, vehicle loading, and road conditions affect the wear rate of the tires.

Treadwear indicators are one way to tell when it is time for new tires. Treadwear indicators appear when the tires have only 1.6mm (1/16 in) or less of tread remaining. See Tire Inspection and Tire Rotation.
The rubber in tires ages over time. This also applies to the spare tire, if the vehicle has one, even if it is never used. Multiple factors including temperatures, loading conditions, and inflation pressure maintenance affect how fast aging takes place. GM recommends that tires, including the spare if equipped, be replaced after six years, regardless of tread wear. The tire manufacturer date is the last four digits of the DOT Tire Identification Number (TIN) which is molded into one side of the tire sidewall. The first two digits represent the week (01–52) and the last two digits, the year. For example, the third week of the year 2010 would have a four-digit DOT date of 0310.
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.
Tire Rotation
Buying New TiresLiftgate Window Replacement
Special Tools
BO-24402-A Glass Sealant Remover (Cold Knife)
BO-39032 Stationary Glass Removal Tool
Use an adhesive that is approved by GM
For equivalent regional tools, refer to Special Tools
Removal Procedure
Warning: Refer to Cracked Window Warning.
Note ...
Front End Upper Tie Bar Replacement
Removal Procedure
Warning: Refer to Approved Equipment for Collision Repair
Warning.
Warning: Refer to Glass and Sheet Metal Handling Warning.
Disable the SIR System. Refer to SIR Disabling and Enabling.
Disconnect the negative battery cable. Refer ...
Transmission Fluid Cooler Flushing and Flow Test
GM studies indicate that plugged or restricted transmission oil coolers and pipes
cause insufficient transmission lubrication and elevated operating temperatures
which can lead to premature transmission failure. Many repeat repair cases could
have been prevented by following published procedur ...