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 TiresInstallation Procedure
Prepare all mating surfaces as necessary.
Align the front hinge pillar body reinforcement.
Drill 8 mm (5/16 in) for plug welding along the edges of the front hinge
pillar body as noted from the original
panel.
Clean and prepare the attaching surfaces for welding.
...
Drunk Driving
Death and injury associated with drinking and driving is a global tragedy.
WARNING
Drinking and then driving is very dangerous. Your reflexes, perceptions, attentiveness,
and judgment can be affected by even a small amount of alcohol. You can have a serious
— or even fatal — collision if you d ...
Loss of Control
Skidding
There are three types of skids that correspond to the vehicle's three control
systems:
• Braking Skid — wheels are not rolling.
• Steering or Cornering Skid — too much speed or steering in a curve causes tires
to slip and lose cornering force.
• Acceleration Skid — too much thro ...