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 TiresAir Conditioning Compressor Replacement (1.6L LDE, LXV, and 1.8L 2H0)
Preliminary Procedures
Recover the refrigerant. Refer to Refrigerant Rec . overy and
Recharging.
Remove drive belt. Refer to Drive Belt Replacement.
Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle.
Disconnect the A/C compressor electrical connector
Re ...
Exhaust Flexible Pipe Replacement (1.6L LXT)
Removal Procedure
Warning: Refer to Hot Exhaust System Warning in the Preface section.
Warning: Refer to Protective Goggles and Glove Warning in the Preface section.
Open the hood.
Raise the vehicle by its full height. Refer to Lifting and Jacking the
Vehicle.
Remove the heate ...
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 rear floor
panel filler as noted from the original
panel.
Clean and prepare the atta ...