gas mileage CHEVROLET IMPALA 2009 9.G Owners Manual

Keep a record with all parts receipts and list the mileage
and the date of any service work performed. See
Maintenance Record on page 6-15.
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
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 5-96.
If the vehicle has the 3.5L V6 engine (VIN Code K)
or the 3.9L V6 engine (VIN Code M), 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 engines, use only the unleaded
gasoline described underGasoline Octane on page 5-5.
Gasoline Octane
For all vehicles except those with the 5.3L V8 engine
(VIN Code C), 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.
5-5