2012 GMC SIERRA 1500 tires

Black plate (15,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Driving and Operating 9-15
If it takes some time for help to
arrive, now and then when you run
the engine, push the accelerator
pedal slightly so the engine runs
faster than the idle speed. This
keeps the battery charged to restart
the vehicle and to signal for help
with the headlamps. Do this as little
as possible to save fuel.
If the Vehicle Is Stuck
Slowly and cautiously spin the
wheels to free the vehicle when
stuck in sand, mud, ice, or snow.
See“Rocking Your Vehicle to Get It
Out” later in this section.
If the vehicle has a traction system,
it can often help to free a stuck
vehicle. Refer to the vehicle's
traction system in the Index. If stuck
too severely for the traction system
to free the vehicle, turn the traction
system off and use the rocking
method.
{WARNING
If the vehicle's tires spin at high
speed, they can explode, and you
or others could be injured. The
vehicle can overheat, causing an
engine compartment fire or other
damage. Spin the wheels as little
as possible and avoid going
above 56 km/h (35 mph).
For information about using tire
chains on the vehicle, see Tire
Chains on page 10‑74.
Rocking Your Vehicle to Get
It Out
Turn the steering wheel left and
right to clear the area around the
front wheels. For four-wheel-drive
vehicles, shift into Four‐Wheel High. For vehicles with StabiliTrak
®, turn
the traction control part of the
system off. Shift back and forth
between R (Reverse) and a forward
gear, spinning the wheels as little as
possible. To prevent transmission
wear, wait until the wheels stop
spinning before shifting gears.
Release the accelerator pedal while
shifting, and press lightly on the
accelerator pedal when the
transmission is in gear. Slowly
spinning the wheels in the forward
and reverse directions causes a
rocking motion that could free the
vehicle. If that does not get the
vehicle out after a few tries, it might
need to be towed out. Recovery
hooks can be used, if the vehicle
has them. If the vehicle does need
to be towed out, see Towing the
Vehicle on page 10‑93.

Black plate (17,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Driving and Operating 9-17
WARNING (Continued)
vehicle handles. This could
cause loss of control and a
crash. Overloading can also
shorten the life of the vehicle.
Tire and Loading Information
Label
Label Example
A vehicle specific Tire and
Loading Information label is
attached to the center pillar
(B-pillar). With the driver door open, you will find the label
attached below the door lock
post (striker). The tire and
loading information label shows
the number of occupant seating
positions (A), and the maximum
vehicle capacity weight (B) in
kilograms and pounds.
The Tire and Loading
Information label also shows the
size of the original equipment
tires (C) and the recommended
cold tire inflation pressures (D).
For more information on tires
and inflation see
Tires on
page 10‑50 andTire Pressure
on page 10‑58.
There is also important loading
information on the vehicle
Certification/Tire label. It tells
you the Gross Vehicle Weight
Rating (GVWR) and the Gross
Axle Weight Rating (GAWR) for the front and rear axles. See
“Certification/Tire Label”
later in
this section.
Steps for Determining Correct
Load Limit
1.
Locate the statement
“The combined weight of
occupants and cargo should
never exceed XXX kg or
XXX lbs” on your vehicle's
placard.
2.Determine the combined
weight of the driver and
passengers that will be riding
in your vehicle.
3.Subtract the combined
weight of the driver and
passengers from XXX kg or
XXX lbs.

Black plate (19,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Driving and Operating 9-19
Example 3
A. Vehicle Capacity Weight for Example 3 = 453 kg (1,000 lbs)
B. Subtract Occupant Weight @ 91 kg (200 lbs) × 5 = 453 kg
(1,000 lbs)
C. Available Cargo Weight = 0 kg (0 lbs)
Refer to your vehicle's tire and
loading information label for
specific information about your
vehicle's capacity weight and
seating positions. The combined weight of the driver, passengers,
and cargo should never exceed
your vehicle's capacity weight.
Certification/Tire Label
A vehicle specific Certification/
Tire label is found on the rear
edge of the driver door. The
label shows the size of your
vehicle's original tires and the
inflation pressures needed
to obtain the gross weight
capacity of your vehicle.
This is called Gross Vehicle
Weight Rating (GVWR). The
GVWR includes the weight of
the vehicle, all occupants, fuel,
and cargo.
The Certification/Tire label also
tells you the maximum weights
for the front and rear axles,
called Gross Axle Weight
Rating (GAWR). To find out the
actual loads on your front and
rear axles, you need to go to a
weigh station and weigh your
vehicle. Your dealer can help
you with this. Be sure to spread
out your load equally on both
sides of the centerline.
Never exceed the GVWR for
your vehicle, or the GAWR for
either the front or rear axle.

Black plate (38,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
9-38 Driving and Operating
1 (First):For the Hydra-Matic
4-Speed transmission this position
reduces vehicle speed even more
than 2 (Second) without using the
brakes. You can use it on very steep
hills, or in deep snow or mud. If the
shift lever is put in 1 (First) while the
vehicle is moving forward, the
transmission does not shift into first
gear until the vehicle is going slowly
enough.
For an Allison Transmission or
Hydra-Matic 6-Speed transmission,
this position reduces vehicle speed
without using the brakes. You can
use it for major/severe downgrades
and off-road driving where the
vehicle would otherwise accelerate
due to steepness of grade. When
you shift to 1 (First) it provides the
lowest gear appropriate to current
road speed and continues to
downshift as the vehicle slows,
eventually downshifting to
1 (First) gear. Notice:
Spinning the tires
or holding the vehicle in one
place on a hill using only the
accelerator pedal may damage
the transmission. The repair will
not be covered by the vehicle
warranty. If you are stuck, do not
spin the tires. When stopping on
a hill, use the brakes to hold the
vehicle in place.
Manual Mode
Range Selection Mode
(Allison®Transmission or
Hydra-Matic®6-Speed
Transmission)
The vehicle may have a Range
Selection Mode. The Range
Selection Mode helps control the vehicle's transmission and vehicle
speed while driving down hill or
towing a trailer by letting you select
a desired range of gears.
To use this feature, do the following:
1. Move the shift lever to
M (Manual Mode).
2. Press the plus/minus buttons, located on the steering column
shift lever, to select the desired
range of gears for current driving
conditions.
When M (Manual Mode) is selected
a number displays next to the M,
indicating the current gear.
This number is the highest gear that
can be used. However, the vehicle
can automatically shift to lower
gears as it adjusts to driving
conditions. This means that all
gears below that number are
available. When 5 (Fifth) is selected,
1 (First) through 5 (Fifth) gears are
automatically shifted by the vehicle,
but 6 (Sixth) cannot be used until

Black plate (39,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Driving and Operating 9-39
the plus/minus button located on the
steering column lever is used to
change to the gear.
Grade Braking is not available when
Range Selection Mode is active.
SeeTow/Haul Mode on page 9‑39.
While using Range Selection Mode,
Cruise Control and the Tow/Haul
Mode can be used.
If the vehicle has an exhaust
brake, it can also be used, but will
not automatically downshift the
transmission. See Exhaust Brake in
the Duramax Diesel supplement.
Notice: Spinning the tires
or holding the vehicle in one
place on a hill using only the
accelerator pedal may damage
the transmission. The repair will
not be covered by the vehicle
warranty. If you are stuck, do not
spin the tires. When stopping on
a hill, use the brakes to hold the
vehicle in place.Low Traction Mode
If your vehicle has the Allison
Transmission, or the Hydra-Matic
6-Speed Automatic Transmission, it
has a Low Traction Mode that can
assist in vehicle acceleration when
road conditions are slippery, such
as with ice or snow. While the
vehicle is at a stop, select the
second gear range using Range
Selection Mode. This will limit
torque to the wheels after it detects
wheel slip, preventing the tires from
spinning.
Tow/Haul Mode
4-Speed Automatic Transmission
6-Speed Automatic Transmission
Vehicles with an automatic
transmission have a Tow/Haul
Mode. The Tow/Haul Mode adjusts
the transmission shift pattern to
reduce shift cycling, providing
increased performance, vehicle
control, and transmission cooling
when driving down steep hills or
Mountain grades, towing, or hauling
heavy loads.
The selector button is located on
the end of the shift lever. Turn
the Tow/Haul Mode on and off by
pressing the button. When the
Tow/Haul Mode is enabled, a light
on the instrument panel cluster will
come on.

Black plate (43,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Driving and Operating 9-43
WARNING (Continued)
before placing the transfer case in
N (Neutral). SeeParking Brake on
page 9‑54.
N (Neutral): Shift to this setting
only when the vehicle needs to be
towed. See Recreational Vehicle
Towing on page 10‑93 orTowing the
Vehicle on page 10‑93.
2
m(Two-Wheel Drive High): This
setting is used for driving in most
street and highway situations.
The front axle is not engaged in
two-wheel drive. This setting also
provides the best fuel economy.
4
m(Four-Wheel Drive High): Use
this setting when you need extra
traction, such as on snowy or icy
roads or in most off-road situations.
This setting also engages the front
axle to help drive your vehicle. This
is the best setting to use when
plowing snow. You can shift from Two-Wheel
Drive High to Four-Wheel Drive
High or Four-Wheel Drive High to
Two-Wheel Drive High while the
vehicle is moving. In extremely cold
weather, it may be necessary to
stop or slow the vehicle to shift into
Four-Wheel Drive High.
When Using the Manual
Transfer Case
.Shifts into or out of Four-Wheel
Drive Low or N (Neutral) should
be made using quick motions to
avoid excessive gear grinding.
Shifting slowly may make it more
difficult to shift.
.You may notice that it is harder
to shift when the vehicle is cold.
After the vehicle warms up the
shifting will return to normal.
.While in Four-Wheel High or
Four-Wheel Drive Low you
may experience reduced fuel
economy.
.Avoid driving in Four-Wheel
Drive on clean, dry pavement.
It may cause your tires to wear
faster, make the transfer case
harder to shift, and run noisier.
.If the transfer case shifter is in
the N (Neutral) position and you
have difficulty reaching the
selected transfer case mode,
with the engine running, shift the
transmission momentarily to
D (Drive) and then back to
N (Neutral). This will realign the
gear teeth in the transfer case
and allow you to complete the
shift.
Shifting from Two-Wheel Drive
High to Four-Wheel Drive High
.Shifts between Two-Wheel Drive
High and Four-Wheel Drive High
can be made at any vehicle
speed.
.Shift the transfer case lever in
one continuous motion into
either the Four-Wheel Drive
High or Two-Wheel Drive High
position.

Black plate (74,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
9-74 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 10‑93. For information on
towing the vehicle behind another vehicle such as a motor home, see
Recreational Vehicle Towing on
page 10‑93.
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 9‑94.
.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

Black plate (75,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Driving and Operating 9-75
Driving with a Trailer
{WARNING
When towing a trailer, exhaust
gases may collect at the rear of
the vehicle and enter if the
liftgate, trunk/hatch, or rear-most
window is open.
Engine exhaust contains Carbon
Monoxide (CO) which cannot be
seen or smelled. It can cause
unconsciousness and even death.
To maximize safety when towing
a trailer:
.Have the exhaust system
inspected for leaks and make
necessary repairs before
starting a trip.
.Never drive with the liftgate,
trunk/hatch, or rear-most
window open.(Continued)
WARNING (Continued)
.Fully open the air outlets on
or under the instrument
panel.
.Adjust the Climate Control
system to a setting that
brings in only outside air and
set the fan speed to the
highest setting. See Climate
Control System in the Index.
For more information about
Carbon Monoxide, see Engine
Exhaust on page 9‑33.
Towing a trailer requires a certain
amount of experience. The
combination you are driving is
longer and not as responsive as the
vehicle itself. Get acquainted with
the handling and braking of the rig
before setting out for the open road.
Before starting, check all trailer
hitch parts and attachments,
safety chains, electrical connectors, lamps, tires, and mirrors. If the
trailer has electric brakes, start the
combination moving and then apply
the trailer brake controller by hand
to be sure the brakes work.
During the trip, check occasionally
to be sure that the load is secure
and the lamps and any trailer
brakes still work.
Following Distance
Stay at least twice as far behind the
vehicle ahead as you would when
driving the vehicle without a trailer.
This can help to avoid heavy
braking and sudden turns.
Passing
More passing distance is needed
when towing a trailer. The
combination will not accelerate
as quickly and is longer so it is
necessary to go much farther
beyond the passed vehicle before
returning to the lane.