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 TiresTire Designations
Tire Size
The following is an example of a typical passenger vehicle tire size.
(1) Passenger (P-Metric) Tire: The United States version of a metric tire
sizing system. The letter P as the first character in the tire size means a passenger
vehicle tire engineered to standards set by the U.S. ...
Installation Procedure
Create 6 x 20 mm (4/16 x 12/16 in) slots for MIG-brazing along the edges
of the rear inner wheelhouse as noted from the original
panel.
Note: If the location of the original plug weld holes can
not be determined, space the slots every 40 mm (1½ in).
Clean and prepare the ...
Ultrasonic Parking Assist
The Ultrasonic Rear Parking Assist (URPA) system assists the driver with parking
and avoiding objects while in R (Reverse). URPA operates at speeds less than 8 km/h
(5 mph). The sensors on the rear bumper detect objects up to 2.5m (8 ft) behind
the vehicle, and at least 20 cm (8 in) off the gr ...