Recommended Fuel

Use regular unleaded gasoline with a posted octane rating of 87 or higher. If the octane rating is less than 87, an audible knocking noise, commonly referred to as spark knock, might be heard when driving.

If this occurs, use a gasoline rated at 87 octane or higher as soon as possible. If heavy knocking is heard when using gasoline rated at 87 octane or higher, the engine needs service.

    See also:

    Navigation
    OnStar navigation requires the Directions and Connections service plan. Push to receive directions or have them sent to the vehicle navigation screen. Destinations can also be forwarded to the vehic ...

    Trailer Brake Control Panel
    A. Manual Trailer Brake Apply Lever B. Trailer Gain Adjustment Buttons The ITBC system has a control panel located on the instrument panel to the left of the steering column. See Instrument Panel ...

    Reporting Safety Defects to General Motors
    In addition to notifying NHTSA (or Transport Canada) in a situation like this, please notify General Motors. Call 1-800-GMC-8782 (1-800-462-8782), or write: GMC Customer Assistance Center P.O. Box ...