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.
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 TiresExterior Lighting Systems Description and Operation
Exterior Lamps
The exterior lighting system consists of the following lamps if equipped:
Headlamps
Daytime Running Lamps (DRL)
Front fog lamps
Rear fog lamps
Park, tail and license lamps
Turn signal lamps
Hazard warning lamps
Repeater lamps
Stop lamps
Backup lamps
Low Beam ...
Aluminum Wheel Porosity Repair
Remove the tire and wheel. Refer to Tire and Wheel Removal
and Installation.
Inflate the tire to the manufactures specified pressure as stated on the
tire.
Submerge the tire/wheel into a water bath in order to locate the leak.
Inscribe a mark on the wheel in order to indic ...
Installation Procedure
Clean and prepare the attaching surfaces for brazing.
Apply structural adhesive to the attaching surfaces.
Position the rear bumper impact bar stud plate on the vehicle.
Verify the fit of the rear bumper impact bar stud plate
Clamp the rear bumper impact bar stud plate into ...