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 TiresHeated Oxygen and Oxygen Sensor Caution
Caution: Do not remove the pigtail from either the heated oxygen
sensor (HO2S) or the oxygen sensor (O2S). Removing the pigtail or the
connector will affect sensor operation.
Handle the oxygen sensor carefully. Do not drop the HO2S. Keep the in-line
electrical connector and the louvered end fr ...
Steering Wheel and Column Description and Operation
The steering wheel and column has 4 primary functions:
Vehicle steering
Vehicle security
Driver convenience
Driver safety
Vehicle Steering
The steering wheel is the first link between the driver and the vehicle. The
steering wheel is fastened to a steering shaft within the
column. A ...
Hill and Mountain Roads
Driving on steep hills or through mountains is different than driving on flat
or rolling terrain. Tips for driving in these conditions include:
• Keep the vehicle serviced and in good shape.
• Check all fluid levels and brakes, tires, cooling system, and transmission.
• Shift to a lower g ...