gas mileage GMC YUKON 2008 Owner's Manual

Your vehicle has an airbag system. Before attempting to
do your own service work, seeServicing Your
Airbag-Equipped Vehicle on page 1-90.
You should keep a record with all parts receipts and list
the mileage and the date of any service work you
perform. SeeMaintenance Record on page 6-17.
Adding Equipment to the Outside of
Your Vehicle
Things you might add to the outside of your vehicle can
affect the airow around it. This can cause wind
noise and can affect fuel economy and windshield
washer performance. Check with your dealer/retailer
before adding equipment to the outside of your vehicle.
Fuel
Use of the recommended fuel is an important part of the
proper maintenance of your vehicle. To help keep the
engine clean and maintain optimum vehicle
performance, we recommend the use of gasoline
advertised as TOP TIER Detergent Gasoline.The 8th digit of the Vehicle Identication Number (VIN)
shows the code letter or number that identies your
vehicle’s engine. The VIN is at the top left of the
instrument panel. SeeVehicle Identification Number
(VIN) on page 5-116.
If your vehicle has the 5.3L V8 engine (VIN Code 0) or the
5.3L V8 engine (VIN Code 3), you can use either regular
unleaded gasoline or ethanol fuel containing up to
85% ethanol (E85); also seeFuel E85 (85% Ethanol) on
page 5-7. In all other engines, use only regular unleaded
gasoline.
Gasoline Octane
Use regular unleaded gasoline with a posted octane
rating of 87 or higher. If the octane rating is less than 87,
you might 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, the
engine needs service.
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