Owner's Manual

If your vehicle has the 4.4L V8 engine (VIN Code D),
use premium unleaded gasoline with a posted
octane rating of 91 or higher. For best performance, use
premium unleaded gasoline with a posted octane
rating of 93. In an emergency, you can use regular
unleaded gasoline with an octane rating of 87 or higher.
If 87 octane fuel is used, do not perform any aggressive
driving maneuvers such as wide open throttle
applications. You may also hear audible spark knock
during acceleration. Refill your tank with premium fuel as
soon as possible to avoid damaging your engine. If
you are using gasoline rated at 91 octane or higher and
you hear heavy knocking, your engine needs service.
Gasoline Specifications
At a minimum, gasoline should meet ASTM
specification D 4814 in the United States or
CAN/CGSB-3.5 in Canada. Some gasolines may
contain an octane-enhancing additive called
methylcyclopentadienyl manganese tricarbonyl (MMT).
General Motors recommends against the use of
gasolines containing MMT. See Additives on page 5-6
for additional information.
California Fuel
If your vehicle is certified to meet California Emissions
Standards, it is designed to operate on fuels that
meet California specifications. See the underhood
emission control label. 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 3-67. 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. In most cases, 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.
5-6