See also:

Defogging and Defrosting
Fog on the inside of windows is a result of high humidity (moisture) condensing on the cool window glass. This can be minimized if the climate control system is used properly. You can use either d ...

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 v ...

When to Add Engine Oil
If the oil is below the L mark for the L6 engine or the cross-hatched area at the tip of the dipstick for the V8 engine, you will need to add at least one quart/liter of oil. But you must use the ...