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 TiresBattery Negative Cable Disconnection and Reconnection
Removal Procedure
Turn on the radio and record all of the customer radio station presets.
Ensure that all lamps and accessories are turned off.
Turn the ignition OFF and remove the ignition key.
Warning: Refer to Battery Disconnect Warning in the Preface section.
Loosen the negati ...
Rear Bumper Fascia Replacement
Preliminary Procedure
Remove the tail lamps. Refer to Tail Lamp Replacement.
Rear Bumper Fascia Retainer (Qty: 2)
Rear Wheelhouse Liner Bolt (Qty: 6)
Caution: Refer to Fastener Caution in the Preface section.
Tighten
2.5 N·m (23 lb in)
Rear Bumper Fascia
Procedure
Pull th ...
Installation Procedure
Note: If the location of the original plug weld holes can not be
determined, space the plug weld holes every 40 mm (1½ in).
Drill 8 mm (5/16 in) for plug welding along the edges of the body rear
end panel as noted from the original panel.
Clean and prepare the attaching s ...