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:

    Shifting Out of Four-Wheel Drive Low
    To shift from Four-Wheel Drive Low to Four-Wheel Drive High, or Two-Wheel Drive High, the vehicle must be stopped or moving less than 5 km/h (3 mph) with the transmission in N (Neutral) and the igniti ...

    Manual Seats
    To adjust the seat: 1. Lift the bar to unlock the seat. 2. Slide the seat to the desired position and release the bar. 3. Try to move the seat back and forth to be sure the seat is locked in pl ...

    Under the Hood
    The Yukon is available with either rear- or four-wheel drive. The Yukon Denali can have an all-wheel-drive system that's distinct from the available part-time four-wheel drive on the regular Yukon ...