Buick 2005 Park Avenue - Manual (Page 237)

If your vehicle has the 3800 Supercharged V6 engine
(VIN Code 1), use only premium unleaded gasoline with
a posted octane of 91 or higher. In an emergency,
you may be able to use a lower octane — as low as
87 — if heavy knocking does not occur. Refill your tank
with premium fuel as soon as possible. Otherwise,
you might damage your engine. If you are using
91 octane or higher-octane fuel and you hear heavy
knocking, your engine needs service.
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.
California Fuel
If your vehicle is certified to meet California Emission
Standards (see the underhood emission control label), it
is designed to operate on fuels that meet California
specifications. If this fuel is not available in states
adopting California emissions standards, your vehicle
will operate satisfactorily on fuels meeting federal
specifications, but emission control system performance
may be affected. The malfunction indicator lamp may
turn on and your vehicle may fail a smog-check test. See
Malfunction Indicator Lamp on page 3-40. If this
occurs, return to your authorized GM dealer for
diagnosis. If it is determined that the condition is caused
by the type of fuel used, repairs may not be covered
by your warranty.
Additives
To provide cleaner air, all gasolines in the United States
are now required to contain additives that will help
prevent engine and fuel system deposits from forming,
allowing your emission control system to work
properly. You should not have to add anything to your
fuel. However, some gasolines contain only the
minimum amount of additive required to meet U.S.
Environmental Protection Agency regulations. General
Motors recommends that you buy gasolines that
are advertised to help keep fuel injectors and intake
valves clean. If your vehicle experiences problems
due to dirty injectors or valves, try a different brand
of gasoline.
Gasolines containing oxygenates, such as ethers and
ethanol, and reformulated gasolines may be available in
your area to contribute to clean air. General Motors
recommends that you use these gasolines, particularly if
they comply with the specifications described earlier.
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