Gasoline Octane

Use regular unleaded gasoline with a posted octane rating of 87 or higher. If the octane rating is less than 87, you may notice an audible knocking noise when you drive, commonly referred to as spark knock. If this occurs, use a gasoline rated at 87 octane or higher as soon as possible.

If you are using gasoline rated at 87 octane or higher and you hear heavy knocking, your engine needs service.

    See also:

    Anti-theft Alarm System Messages
    THEFT ATTEMPTED This message displays if the vehicle detects a tamper condition. ...

    How to Inspect the Engine Air Cleaner/Filter
    To inspect the air cleaner/filter, remove the filter from the vehicle and lightly shake the filter to release loose dust and dirt. If the filter remains caked with dirt, a new filter is required ...

    Reactivation for Subsequent Owners
    Push and follow the prompts to speak to an Advisor as soon as possible after acquiring the vehicle. The Advisor will update vehicle records and will explain the OnStar service offers and opt ...