Buick 2004 Park Avenue - Manual (Page 249)

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.
Gasoline meeting these specifications could provide
improved driveability and emission control system
performance compared to other gasoline.
In Canada, look for the
“Auto Makers’ Choice”
label on the pump.
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 (see Malfunction Indicator Lamp on page 3-41 )
and your vehicle may fail a smog-check test. 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.
Canada Only
5-5