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 TiresRear Compartment Lid Emblem/Nameplate Replacement (LT or LTZ)
Rear Compartment Lid Emblem Assembly
Caution: Refer to Exterior Trim Emblem Removal Caution in the
Preface section.
Procedure
The part and surface should be 21°C (70°F) prior to installation. The
vehicle should remain 21°C (70°F) for
one hour after assembly to allow adhesive to deve ...
Installation Procedure
Drill 8 mm (5/16 in) for plug welding along the edges of the service
panel as noted from the original panel.
Clean and prepare the attaching surfaces for welding.
Apply one-part windshield urethane adhesive as noted
from the original panel.
Position the roof ...
Adding Equipment to the Airbag-Equipped Vehicle
Adding accessories that change the vehicle's frame, bumper system, height, front
end, or side sheet metal, may keep the airbag system from working properly. The
operation of the airbag system can also be affected by changing or moving any parts
of the front seats, safety belts, the airbag ...