Engine Oil Additives/Engine Oil Flushes

Do not add anything to the oil. The recommended oils with the dexos specification and displaying the dexos certification mark are all that is needed for good performance and engine protection.

Engine oil system flushes are not recommended and could cause engine damage not covered by the vehicle warranty.

    See also:

    When to Check and Change AutomaticTransmission Fluid
    A good time to check your automatic transmission fluid level is when the engine oil is changed. Change the fluid and filter at the intervals listed in Additional Required Services on page 482, and ...

    California Fuel Requirements
    If the vehicle is certified to meet California Emissions Standards, it is designed to operate on fuels that meet California specifications. See the underhood emission control label. If this ...

    TTY Users
    OnStar has the ability to communicate to the deaf, hard-of-hearing, or speech-impaired customers while in the vehicle. The available dealer-installed TTY system can provide in-vehicle acce ...