See also:

Treadwear
The treadwear grade is a comparative rating based on the wear rate of the tire when tested under controlled conditions on a specified government test course. For example, a tire graded 150 would wear ...

Tire Rotation
Tires should be rotated every 12 000 km (7,500 mi). See Maintenance Schedule on page 11‑3. Tires are rotated to achieve a uniform wear for all tires. The first rotation is the most important. ...

Vehicle and Power Issues
OnStar services require a vehicle electrical system, wireless service, and GPS satellite technologies to be available and operating for features to function properly. These systems may not operate if ...