2007 GMC SIERRA Owner's Manual

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 Specications
At a minimum, gasoline should meet ASTM
specication 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. SeeAdditives
on page 490for additional information.
California Fuel
If your vehicle is certied to meet California
Emissions Standards, it is designed to operate on
fuels that meet California specications. 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
specications, but emission control system
performance may be affected. The malfunction
indicator lamp may turn on and your vehicle may
fail a smog-check test. SeeMalfunction Indicator
Lamp on page 260. 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.
489

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.
To help keep fuel injectors and intake valves clean,
or if your vehicle experiences problems due to
dirty injectors or valves, look for gasoline that is
advertised as TOP TIER Detergent Gasoline. Also,
your dealer has additives that will help correct
and prevent most deposit-related problems.
Gasolines containing oxygenates, such as ethers
and ethanol, and reformulated gasolines may
be available in your area. General Motors
recommends that you use these gasolines if they
comply with the specications 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:Your 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 your warranty.
Some gasolines that are not reformulated for low
emissions may contain an octane-enhancing
additive called methylcyclopentadienyl manganese
tricarbonyl (MMT); ask the attendant where you
buy gasoline whether the fuel contains MMT.
General Motors recommends against the use of
such gasolines. Fuels containing MMT can reduce
the life of spark plugs and the performance of
the emission control system may be affected. The
malfunction indicator lamp may turn on. If this
occurs, return to your dealer for service.
490

Fuel E85 (85% Ethanol)
The 8th digit of the Vehicle Identication Number
(VIN) shows the code letter or number that
identies your vehicle’s engine. The VIN is at the
top left of the instrument panel. SeeVehicle
Identication Number (VIN) on page 607.
If your vehicle has the 5.3L V8 engine (VIN
Code 0) or the 5.3L V8 engine (VIN Code 3), you
can use either regular unleaded gasoline or
ethanol fuel containing up to 85% ethanol (E85);
also seeFuel on page 488. In all other engines,
use only the unleaded gasoline described
underGasoline Octane on page 489.
Only vehicles that have the 5.3L V8 engine
(VIN Code 0) or the 5.3L V8 engine (VIN Code 3)
can use 85% ethanol fuel (E85). 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 nd 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%.
At a minimum, E85 should meet ASTM
Specication D 5798. By denition, this means
that fuel labeled E85 will have an ethanol content
between 70% and 85%. Filling the fuel tank
with fuel mixtures that do not meet ASTM
specications can affect driveability and could
cause the malfunction indicator lamp to come on.
491

To ensure quick starts in the wintertime, the E85
fuel must be formulated properly for your
climate according to ASTM specication D 5798.
If you have trouble starting on E85, it could
be because the E85 fuel is not properly formulated
for your climate. If this happens, switching to
gasoline or adding gasoline to the fuel tank can
improve starting. For good starting and heater
efficiency below 32°F (0°C), the fuel mix in the fuel
tank should contain no more than 70% ethanol.
It is best not to alternate repeatedly between
gasoline and E85. If you do switch fuels, it
is recommended that you add as much fuel as
possible — do not add less than three gallons
(11 L) when refueling. You should drive the vehicle
immediately after refueling for at least seven miles
(11 km) to allow the vehicle to adapt to the
change in ethanol concentration.
E85 has less energy per gallon than gasoline, so
you will need to rell the fuel tank more often
when using E85 than when you are using gasoline.
SeeFilling the Tank on page 493.Notice:Some additives are not compatible
with E85 fuel and can harm your vehicle’s fuel
system. Damage caused by additives would
not be covered by your new vehicle warranty.
Notice:Your 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 your 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 nd. 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 your
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.
492

Filling the Tank
If your vehicle has the DURAMAX®Diesel engine,
see the DURAMAX®Diesel manual for more
information.
{CAUTION:
Fuel vapor burns violently and a fuel re
can cause bad injuries. To help avoid
injuries to you and others, read and follow
all the instructions on the pump island.
Turn off your engine when you are
refueling. Do not smoke if you are near
fuel or refueling your vehicle. Do not use
cellular phones. Keep sparks, ames, and
smoking materials away from fuel. Do not
leave the fuel pump unattended when
refueling your vehicle. This is against the
law in some places. Do not re-enter the
vehicle while pumping fuel. Keep children
away from the fuel pump; never let
children pump fuel.The tethered fuel cap is located behind a hinged
fuel door on the driver’s side of the vehicle. If
the vehicle has E85 fuel capability, a yellow cap
with the words “E85 / Gasoline” can be seen.
493

To remove the fuel cap, turn it slowly
counterclockwise.
{CAUTION:
Fuel can spray out on you if you open the
fuel cap too quickly. If you spill fuel and
then something ignites it, you could be
badly burned. This spray can happen if
your tank is nearly full, and is more likely
in hot weather. Open the fuel cap slowly
and wait for any hiss noise to stop. Then
unscrew the cap all the way.
If your vehicle is a dual fuel tank chassis cab
model, and it runs out of fuel, refuel the front fuel
tank rst to ensure a quick restart.Be careful not to spill fuel. Do not top off or overll
the tank and wait a few seconds after you have
nished pumping before removing the nozzle.
Clean fuel from painted surfaces as soon as
possible. SeeWashing Your Vehicle on page 601.
When replacing the fuel cap, turn it clockwise until
it clicks. It will require more effort to turn the
fuel cap on the last turn as you tighten it. Make
sure the cap is fully installed. The diagnostic
system can determine if the fuel cap has been left
off or improperly installed. This would allow fuel
to evaporate into the atmosphere. SeeMalfunction
Indicator Lamp on page 260.
The TIGHTEN GAS CAP message will be
displayed on the Driver Information Center (DIC) if
the fuel cap is not properly installed. SeeDIC
Warnings and Messages on page 279for more
information.
494

{CAUTION:
If a re starts while you are refueling, do
not remove the nozzle. Shut off the ow of
fuel by shutting off the pump or by
notifying the station attendant. Leave the
area immediately.
Notice:If you need a new fuel cap, be sure to
get the right type. Your dealer/retailer can
get one for you. If you get the wrong type, it
may not t properly. This may cause your
malfunction indicator lamp to light and may
damage your fuel tank and emissions system.
SeeMalfunction Indicator Lamp on page 260.
Filling a Portable Fuel Container
{CAUTION:
Never ll a portable fuel container while it
is in your vehicle. Static electricity
discharge from the container can ignite the
gasoline vapor. You can be badly burned
and your vehicle damaged if this occurs.
To help avoid injury to you and others:
Dispense gasoline only into approved
containers.
Do not ll a container while it is inside a
vehicle, in a vehicle’s trunk, pickup
bed, or on any surface other than the
ground.
Bring the ll nozzle in contact with the
inside of the ll opening before
operating the nozzle. Contact should
be maintained until the lling is
complete.
Do not smoke while pumping gasoline.
Do not use a cellular phone while
pumping gasoline.
495

Checking Things Under
the Hood
{CAUTION:
An electric engine cooling fan can start
even when the engine is not running.
To avoid injury, always keep hands,
clothing, and tools away from any engine
cooling fan.
{CAUTION:
Things that burn can get on hot engine
parts and start a re. These include
liquids like fuel, oil, coolant, brake uid,
windshield washer and other uids, and
plastic or rubber. You or others could be
burned. Be careful not to drop or spill
things that will burn onto a hot engine.
496