Fuel; Gasoline Octane; Gasoline Specifications; California Fuel - Buick 2009 Enclave Owner's Manual

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.

Gasoline Octane

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.
Gasoline Specifications
At a minimum, gasoline
should meet ASTM specification
D 4814 in the United States or
CAN/CGSB-3.5 or 3.511 in Canada.
Some gasolines contain an
octane-enhancing additive called
methylcyclopentadienyl manganese
tricarbonyl (MMT). We recommend
against the use of gasolines
containing MMT. See Additives on
page 5-5 for additional information.

California Fuel

If the 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, the vehicle will operate
satisfactorily on fuels meeting federal
specifications, but emission control
system performance might be
affected. The malfunction indicator
lamp could turn on and the vehicle
Service and Appearance Care
might fail a smog-check test. See
Malfunction Indicator Lamp on
page 3-37. If this occurs, return to
your authorized dealer/retailer for
diagnosis. If it is determined that the
condition is caused by the type of
fuel used, repairs might not be
covered by the vehicle warranty.

Additives

To provide cleaner air, all gasolines
in the United States are now required
to contain additives that help prevent
engine and fuel system deposits
from forming, allowing the emission
control system to work properly. In
most cases, you should not have to
add anything to the fuel. However,
some gasolines contain only the
minimum amount of additive required
to meet U.S. Environmental
Protection Agency regulations. To
help keep fuel injectors and intake
valves clean, or if the vehicle
experiences problems due to dirty
injectors or valves, look for gasoline
that is advertised as TOP TIER
Detergent Gasoline.
5-5