See also:

General Information
For service and parts needs, visit your dealer. You will receive genuine GM parts and GM-trained and supported service people. Genuine GM parts have one of these marks: ...

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 ...

Diagnostics
OnStar Vehicle Diagnostics will perform a vehicle check every month. It will check the engine, transmission, antilock brakes, and major vehicle systems. It also checks the tire pressures, if the vehic ...