2011 CHEVROLET IMPALA octane

Black plate (35,1)Chevrolet Impala Owner Manual - 2011
Driving and Operating 9-35
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.
Look for the TOP TIER label on the
fuel pump to ensure gasoline meets
enhanced detergency standards
developed by auto companies. A list
of marketers providing TOP TIER
Detergent Gasoline can be found at
www.toptiergas.com.
Vehicles that have a FlexFuel badge
and a yellow fuel cap can use either
unleaded gasoline or ethanol fuel
containing up to 85% ethanol (E85).
SeeFuel E85 (85% Ethanol) on
page 9‑37. For all other vehicles,
use only the unleaded gasoline
described under Recommended
Fuel on page 9‑35.
Recommended Fuel
Use regular unleaded gasoline with
a posted octane rating of 87 or
higher. If the octane rating is less
than 87, an audible knocking noise,
commonly referred to as spark
knock, might be heard when driving.
If this occurs, use a gasoline rated
at 87 octane or higher as soon as
possible. If heavy knocking is heard
when using gasoline rated at
87 octane or higher, the engine
needs service.

Black plate (36,1)Chevrolet Impala Owner Manual - 2011
9-36 Driving and Operating
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. SeeFuel Additives
on page 9‑36 for additional
information.
California Fuel
Requirements
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 might fail a smog‐check test.
See
Malfunction Indicator Lamp on
page 5‑17. If this occurs, return to
your authorized dealer 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.
Fuels in Foreign
Countries
If you plan on driving in another
country outside the United States or
Canada, the proper fuel might be
hard to find. Never use leaded
gasoline or any other fuel not
recommended in the previous text
on fuel. Costly repairs caused by
use of improper fuel would not be
covered by the vehicle warranty.
To check the fuel availability, ask an
auto club, or contact a major oil
company that does business in the
country where you will be driving.
Fuel 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, nothing
should have to be added 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. Look for the TOP TIER
label on the fuel pump to ensure
gasoline meets enhanced
detergency standards developed by
the auto companies. A list of
marketers providing TOP TIER
Detergent Gasoline can be found at
www.toptiergas.com.

Black plate (37,1)Chevrolet Impala Owner Manual - 2011
Driving and Operating 9-37
For customers who do not use TOP
TIER Detergent Gasoline regularly,
one bottle of GM Fuel System
Treatment PLUS, added to the fuel
tank at every engine oil change,
can help clean deposits from fuel
injectors and intake valves. GM Fuel
System Treatment PLUS is the only
gasoline additive recommended by
General Motors. It is available at
your dealer.
Gasolines containing oxygenates,
such as ethers and ethanol, and
reformulated gasolines might be
available in your area. We
recommend that you use these
gasolines, if they comply with the
specifications described earlier.
However, E85 (85% ethanol) and
other fuels containing more than
10% ethanol must not be used in
vehicles that were not designed
for those fuels.Notice:
This vehicle was not
designed for fuel that contains
methanol. Do not use fuel
containing methanol. It can
corrode metal parts in the fuel
system and also damage plastic
and rubber parts. That damage
would not be covered under the
vehicle warranty.
Some gasolines that are not
reformulated for low emissions can
contain an octane-enhancing
additive called
methylcyclopentadienyl manganese
tricarbonyl (MMT); ask the attendant
where you buy gasoline whether the
fuel contains MMT. We recommend
against the use of such gasolines.
Fuels containing MMT can reduce
the life of spark plugs and the
performance of the emission control
system could be affected. The
malfunction indicator lamp might
turn on. If this occurs, return to your
dealer for service.Fuel E85 (85% Ethanol)
Vehicles that have a FlexFuel badge
and a yellow fuel cap can use either
unleaded gasoline or ethanol fuel
containing up to 85% ethanol (E85).
For all other vehicles, use only the
unleaded gasoline described under
Recommended Fuel on page 9‑35.
We encourage the use of E85 in
vehicles that are designed to use it.
The ethanol in E85 is a “renewable”
fuel, meaning it is made from
renewable sources such as corn
and other crops.
Many service stations will not have
an 85% ethanol fuel (E85) pump
available. The U.S. Department of
Energy has an alternative fuels
website (www.eere.energy.gov/afdc/
infrastructure/locator.html) that can
help you find E85 fuel. Those
stations that do have E85 should
have a label indicating ethanol
content. Do not use the fuel if the
ethanol content is greater than 85%.