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 TiresLamp Messages
AUTOMATIC LIGHT CONTROL ON
This message is displayed when the automatic light control has been turned on.
AUTOMATIC LIGHT CONTROL OFF
This message is displayed when the automatic light control has been turned off.
XXX TURN INDICATOR FAILURE
When one of the turn signals is out, this message disp ...
Power Steering
Specifications
Power Steering System Bleeding
Note:
Use clean, new power steering fluid type only. See the Maintenance
and Lubrication subsection for fluid specifications.
Hoses touching the frame, body or engine may cause system noise.
Verify that the hoses do not touch any ot ...
Child Restraint Systems
Rear-Facing Infant Seat
A rear-facing infant seat provides restraint with the seating surface against
the back of the infant.
The harness system holds the infant in place and, in a crash, acts to keep the
infant positioned in the restraint.
Forward-Facing Child Seat
A forward-facing chil ...