Page 377 of 588

Black plate (83,1)Chevrolet Silverado Owner Manual - 2011
Driving and Operating 9-83
Fuel
For diesel engine vehicles, see
“Fuel for Diesel Engines”in the
Duramax Diesel Supplement.
For Vehicles with gasoline engines,
please read this.
Gasoline
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.
The 8th digit of the Vehicle
Identification Number (VIN) shows
the code letter or number that identifies the vehicle's engine.
The VIN is at the top left of the
instrument panel. See
Vehicle
Identification Number (VIN)
on
page 12‑1.
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).
See Fuel E85 (85% Ethanol)
on
page 9‑86. For all other vehicles,
use only the unleaded gasoline
described under Recommended
Fuel on page 9‑84.
Page 378 of 588

Black plate (84,1)Chevrolet Silverado Owner Manual - 2011
9-84 Driving and Operating
Recommended Fuel
For all vehicles except those with
the 6.2L V8 engine (VIN Code 2),
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.
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 sparkknock, 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
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
Fuel Additives
on page 9‑85for 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 5‑27. 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.
Page 379 of 588

Black plate (85,1)Chevrolet Silverado Owner Manual - 2011
Driving and Operating 9-85
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 DetergentGasoline. 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.
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.
Page 380 of 588

Black plate (86,1)Chevrolet Silverado Owner Manual - 2011
9-86 Driving and Operating
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 9‑84.
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.
Page 381 of 588

Black plate (87,1)Chevrolet Silverado Owner Manual - 2011
Driving and Operating 9-87
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 Specification D 5798.
By definition, 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
specifications can affect driveability
and could cause the malfunction
indicator lamp to come on.
To ensure quick starts in the
wintertime, the E85 fuel must be
formulated properly for your climate
according to ASTM specification
D 5798. If you have trouble starting
on E85, it could be because theE85 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 0°C
(32°F), 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
11 L (three gallons) when refueling.
You should drive the vehicle
immediately after refueling for at
least 11 km (seven miles) 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
refill the fuel tank more often when
using E85 than when you are using
gasoline. See
Filling the Tank
on
page 9‑88.
Notice: Some additives are not
compatible with E85 fuel and can
harm the vehicle's fuel system.
Do not add anything to E85.
Damage caused by additives
would not be covered by the
vehicle warranty.
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.
Page 382 of 588

Black plate (88,1)Chevrolet Silverado Owner Manual - 2011
9-88 Driving and Operating
Filling the Tank
If the vehicle has a diesel engine,
see the Duramax diesel supplement
for more information.
{WARNING
Fuel vapor burns violently and a
fuel fire can cause bad injuries.
To help avoid injuries to you and
others, read and follow all the
instructions on the fuel pump
island. Turn off the engine when
refueling. Do not smoke near
fuel or when refueling the vehicle.
Do not use cellular phones. Keep
sparks, flames, and smoking
materials away from fuel. Do not
leave the fuel pump unattended
when refueling the 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 side of the vehicle. If the
vehicle has E85 fuel capability,
the fuel cap will be yellow and state
that E85 or gasoline can be used.
SeeFuel E85 (85% Ethanol)
on
page 9‑86.
To remove the fuel cap, turn it
slowly counterclockwise.
{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
“Washing the Vehicle” in Exterior
Cleaning.
Page 383 of 588

Black plate (89,1)Chevrolet Silverado Owner Manual - 2011
Driving and Operating 9-89
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 5‑27.
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 5‑48for 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 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 5‑27.
Filling a Portable Fuel
Container
{WARNING
Never fill a portable fuel container
while it is in the vehicle. Static
electricity discharge from the
container can ignite the fuel
vapor. You can be badly burned
(Continued)
WARNING (Continued)
and the vehicle damaged if this
occurs. To help avoid injury to you
and others:
.Dispense fuel only into
approved containers.
.Do not fill 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 fill nozzle in contact
with the inside of the fill
opening before operating the
nozzle. Contact should be
maintained until the filling is
complete.
.Do not smoke while
pumping fuel.
.Do not use a cellular phone
while pumping fuel.
Page 384 of 588

Black plate (90,1)Chevrolet Silverado Owner Manual - 2011
9-90 Driving and Operating
Towing
General Towing
Information
Only use towing equipment that
has been designed for the vehicle.
Contact your dealer or trailering
dealer for assistance with preparing
the vehicle for towing a trailer.
See the following trailer towing
information in this section:
.For information on driving while
towing a trailer, see“Driving
Characteristics and
Towing Tips.”
.For maximum vehicle and trailer
weights, see “Trailer Towing.”
.For information on equipment
to tow a trailer, see “Towing
Equipment.” For information on towing a disabled
vehicle, see
Towing the Vehicle
on
page 10‑101. For information on
towing the vehicle behind another
vehicle such as a motorhome, see
Recreational Vehicle Towing
on
page 10‑101.
Driving Characteristics
and Towing Tips
Pulling a Trailer
Important points for pulling a trailer:
.There are many different laws,
including speed limit restrictions,
having to do with trailering.
Make sure the rig will be legal,
not only where you live but
also where you will be driving.
A good source for this
information can be state
or provincial police.
.Consider using a sway control.
See “Hitches” underTowing
Equipment on page 9‑111.
.Do not tow a trailer at all during
the first 800 km (500 miles)
the new vehicle is driven.
The engine, axle, or other
parts could be damaged.
.During the first 800 km
(500 miles) that a trailer is
towed, do not drive over
80 km/h (50 mph) and do
not make starts at full throttle.
This helps the engine and other
parts of the vehicle wear in at
the heavier loads.
.Vehicles can tow in D (Drive).
Shift the transmission to a lower
gear if the transmission shifts
too often under heavy loads
and/or hilly conditions.
Important considerations that have
to do with weight:
.Weight of the trailer
.Weight of the trailer tongue
.Weight on the vehicle's tires
.Weight of the trailering
combination