Pontiac 2005 Grand Prix - Manual (Page 295)

Adding Equipment to the Outside
of Your Vehicle
Things you might add to the outside of your vehicle
can affect the airflow around it. This may cause
wind noise and affect windshield washer performance.
Check with your dealer before adding equipment to
the outside of your vehicle.
Fuel
The 8th digit of your vehicle identification number (VIN)
shows the code letter or number that identifies your
engine. You will find the VIN at the top left of the
instrument panel. See Vehicle Identification Number
(VIN) on page 5-102.
Gasoline Octane
If your vehicle has the 3800 V6 engine (VIN Code 2),
use regular unleaded gasoline with a posted octane
of 87 or higher. If the octane is less than 87, you may
get a heavy knocking noise when you drive. If it is
bad enough, it can damage your engine. A little pinging
noise when you accelerate or drive uphill is considered
normal. This does not indicate a problem exists or
that a higher-octane fuel is necessary.
If your vehicle has the 3800 Supercharged V6 engine
(VIN Code 4), use premium unleaded gasoline with
a posted octane of 91 or higher for best performance.
You may also use middle grade or regular unleaded
gasoline rated at 87 octane or higher, but your vehicle’s
acceleration may be slightly reduced. If the octane is
less than 87, you may get a heavy knocking noise when
you drive. If it is bad enough, it can damage your
engine.
Gasoline Specifications
It is recommended that gasoline meet specifications
which were developed by automobile manufacturers
around the world and contained in the World-Wide Fuel
Charter which is available from the Alliance of Automobile
Manufacturers at www.autoalliance.org/fuel_charter.htm.
Gasoline meeting these specifications could provide
improved driveability and emission control system
performance compared to other gasoline.
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