gas mileage GMC SIERRA 2009 Owner's Manual

This vehicle has an airbag system. Before attempting to
do your own service work, seeServicing Your
Airbag-Equipped Vehicle on page 1-88.
Keep a record with all parts receipts and list the mileage
and the date of any service work performed. See
Maintenance Record on page 6-19.
Adding Equipment to the Outside of
the Vehicle
Things added to the outside of the 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 the vehicle.
Fuel
For diesel engine vehicles, see “Diesel Fuel
Requirements and Fuel System” in the DURAMAX®
Diesel manual.
For vehicles with gasoline engines, please read this.
Gasoline
Use of the recommended fuel is an important part of the
proper maintenance of this 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 the
vehicle’s engine. The VIN is at the top left of the
instrument panel. SeeVehicle Identification Number
(VIN) on page 5-121.
If the vehicle has the 5.3L V8 engine (VIN Code 0), the
5.3L V8 engine (VIN Code 3), or the 6.2L V8 engine
(VIN Code 2), you can use either unleaded gasoline
or ethanol fuel containing up to 85% ethanol (E85).
SeeFuel E85 (85% Ethanol) on page 5-8. In all other
gasoline engines, use only unleaded gasoline.
SeeGasoline Octane on page 5-6.
Gasoline Octane
For all vehicles except those with the 6.2L V8 engine
(VIN Code 2), 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.
If the vehicle has the 6.2L V8 engine (VIN Code 2), use
premium unleaded gasoline with a posted octane rating
of 91 or higher. You can also use regular unleaded
gasoline rated at 87 octane or higher, but the vehicle’s
acceleration could be slightly reduced, and you might
5-6