Black plate (85,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-85
If the vehicle has the 6.2L V8 engine
(VIN Code 2), use premium
unleaded gasoline with a posted
octane rating of 91 or higher.
You can also use regular unleaded
gasoline rated at 87 octane or
higher, but the vehicle's acceleration
could be slightly reduced, and
a slight audible knocking noise,
commonly referred to as spark
knock, might be heard. If the octane
is less than 87, you might notice
a heavy knocking noise when you
drive. If this occurs, use a gasoline
rated at 87 octane or higher as soon
as possible. Otherwise, you could
damage the engine. If heavy
knocking is heard when using
gasoline rated at 87 octane or
higher, the engine needs service.Gasoline Specifications
(U.S. and Canada Only)
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 9‑86 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 5‑25. 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.
Black plate (89,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-89
{WARNING
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 the 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 the vehicle is a dual fuel tank
chassis cab model, and it runs out
of fuel, refuel the front fuel tank first
to ensure a quick restart.
Be careful not to spill fuel. Do not
top off or overfill the tank and wait a
few seconds after you have finished pumping before removing the
nozzle. Clean fuel from painted
surfaces as soon as possible.
See
Exterior Care on page 10‑108.
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. See Malfunction
Indicator Lamp on page 5‑25.
The TIGHTEN GAS CAP message
displays on the Driver Information
Center (DIC) if the fuel cap is not
properly installed. See Fuel System
Messages on page 5‑46 for more
information.
{WARNING
If a fire starts while you are
refueling, do not remove the
nozzle. Shut off the flow of fuel
by shutting off the pump or by
notifying the station attendant.
Leave the area immediately.
Notice: If a new fuel cap is
needed, be sure to get the right
type of cap from your dealer.
The wrong type of fuel cap might
not fit properly, might cause the
malfunction indicator lamp to
light, and could damage the
fuel tank and emissions system.
See Malfunction Indicator Lamp
on page 5‑25.
