
Black plate (16,1)GMC Sierra Owner Manual - 2011
9-16 Driving and Operating
Driving Across an Incline
An off-road trail will probably go
across the incline of a hill. To decide
whether to try to drive across the
incline, consider the following:
{WARNING
Driving across an incline that is
too steep will make your vehicle
roll over. You could be seriously
injured or killed. If you have any
doubt about the steepness of the
incline, do not drive across it.
Find another route instead.
.A hill that can be driven straight
up or down might be too steep
to drive across. When going
straight up or down a hill, the
length of the wheel base—the
distance from the front wheels to
the rear wheels —reduces the
likelihood the vehicle will tumble end over end. But when driving
across an incline, the narrower
track width
—the distance
between the left and right
wheels —might not prevent the
vehicle from tilting and rolling
over. Driving across an incline
puts more weight on the downhill
wheels which could cause a
downhill slide or a rollover.
.Surface conditions can be a
problem. Loose gravel, muddy
spots, or even wet grass can
cause the tires to slip sideways,
downhill. If the vehicle slips
sideways, it can hit something
that will trip it —a rock, a rut,
etc. —and roll over.
.Hidden obstacles can make the
steepness of the incline even
worse. If you drive across a rock
with the uphill wheels, or if the
downhill wheels drop into a rut
or depression, the vehicle can tilt
even more. For these reasons, carefully
consider whether to try to drive
across an incline. Just because
the trail goes across the incline
does not mean you have to drive it.
The last vehicle to try it might have
rolled over.
If you feel the vehicle starting
to slide sideways, turn downhill.
This should help straighten out
the vehicle and prevent the side
slipping. The best way to prevent
this is to
“walk the course” first, so
you know what the surface is like
before driving it.

Black plate (17,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-17
Stalling on an Incline
{WARNING
Getting out on the downhill (low)
side of a vehicle stopped across
an incline is dangerous. If the
vehicle rolls over, you could be
crushed or killed. Always get out
on the uphill (high) side of the
vehicle and stay well clear of the
rollover path.
If the vehicle stalls when crossing
an incline, be sure you, and
any passengers, get out on the
uphill side, even if the door there
is harder to open. If you get out on
the downhill side and the vehicle
starts to roll over, you will be right
in its path.
If you have to walk down the slope,
stay out of the path the vehicle will
take if it does roll over.
Driving in Mud, Sand, Snow,
or Ice
When you drive in mud, snow,
or sand, the wheels do not get
good traction. Acceleration is not
as quick, turning is more difficult,
and braking distances are longer.
It is best to use a low gear when
in mud —the deeper the mud, the
lower the gear. In really deep mud,
keep the vehicle moving so it does
not get stuck.
When driving on sand, wheel
traction changes. On loosely packed
sand, such as on beaches or sand
dunes, the tires will tend to sink into
the sand. This affects steering,
accelerating, and braking. Drive at
a reduced speed and avoid sharp
turns or abrupt maneuvers. Hard packed snow and ice offer
the worst tire traction. On these
surfaces, it is very easy to lose
control. On wet ice, for example,
the traction is so poor that you
will have difficulty accelerating.
And, if the vehicle does get moving,
poor steering and difficult braking
can cause it to slide out of control.
{WARNING
Driving on frozen lakes, ponds,
or rivers can be dangerous.
Underwater springs, currents
under the ice, or sudden thaws
can weaken the ice. Your vehicle
could fall through the ice and
you and your passengers could
drown. Drive your vehicle on safe
surfaces only.

Black plate (18,1)GMC Sierra Owner Manual - 2011
9-18 Driving and Operating
Driving in Water
{WARNING
Driving through rushing water can
be dangerous. Deep water can
sweep your vehicle downstream
and you and your passengers
could drown. If it is only shallow
water, it can still wash away the
ground from under your tires, and
you could lose traction and roll
the vehicle over. Do not drive
through rushing water.
Heavy rain can mean flash flooding,
and flood waters demand extreme
caution. Find out how deep the water is
before driving through it. Do not
try it if it is deep enough to cover
the wheel hubs, axles, or exhaust
pipe
—you probably will not get
through. Deep water can damage
the axle and other vehicle parts.
If the water is not too deep, drive
slowly through it. At faster speeds,
water splashes on the ignition
system and the vehicle can stall.
Stalling can also occur if you get the
tailpipe under water. If the tailpipe is
under water, you will never be able
to start the engine. When going
through water, remember that when
the brakes get wet, it might take
longer to stop. See Driving on Wet
Roads on page 9‑19.
After Off-Road Driving
Remove any brush or debris that
has collected on the underbody,
chassis, or under the hood. These
accumulations can be a fire hazard.
After operation in mud or sand,
have the brake linings cleaned and
checked. These substances can
cause glazing and uneven braking.
Check the body structure, steering,
suspension, wheels, tires, and
exhaust system for damage and
check the fuel lines and cooling
system for any leakage.
The vehicle requires more frequent
service due to off-road use. Refer
to the Maintenance Schedule for
additional information.

Black plate (21,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-21
{WARNING
Coasting downhill in N (Neutral)
or with the ignition off is
dangerous. The brakes will
have to do all the work of slowing
down and they could get so hot
that they would not work well.
You would then have poor braking
or even none going down a hill.
You could crash. Always have the
engine running and the vehicle in
gear when going downhill.
.Stay in your own lane. Do not
swing wide or cut across the
center of the road. Drive at
speeds that let you stay in
your own lane.
.Top of hills: Be alert—
something could be in your
lane (stalled car, accident).
.Pay attention to special road
signs (falling rocks area, winding
roads, long grades, passing or
no-passing zones) and take
appropriate action.
Winter Driving
Driving on Snow or Ice
Drive carefully when there is snow
or ice between the tires and the
road, creating less traction or grip.
Wet ice can occur at about 0°C
(32°F) when freezing rain begins to
fall, resulting in even less traction.
Avoid driving on wet ice or in
freezing rain until roads can be
treated with salt or sand.
Drive with caution, whatever the
condition. Accelerate gently so
traction is not lost. Accelerating too
quickly causes the wheels to spin
and makes the surface under the
tires slick, so there is even less
traction. Try not to break the fragile traction.
If you accelerate too fast, the drive
wheels will spin and polish the
surface under the tires even more.
The
Antilock Brake System (ABS)
on page 9‑68 improves vehicle
stability during hard stops on
slippery roads, but apply the brakes
sooner than when on dry pavement.
Allow greater following distance on
any slippery road and watch for
slippery spots. Icy patches can
occur on otherwise clear roads in
shaded areas. The surface of a
curve or an overpass can remain
icy when the surrounding roads
are clear. Avoid sudden steering
maneuvers and braking while
on ice.
Turn off cruise control on slippery
surfaces.

Black plate (23,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-23
To save fuel, run the engine for only
short periods as needed to warm
the vehicle and then shut the engine
off and close the window most of
the way to save heat. Repeat this
until help arrives but only when you
feel really uncomfortable from the
cold. Moving about to keep warm
also helps.
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 55 km/h
(35 mph).
For information about using tire
chains on the vehicle, see Tire
Chains on page 10‑83.

Black plate (24,1)GMC Sierra Owner Manual - 2011
9-24 Driving and Operating
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 10‑103.
Recovery Hooks
{WARNING
These hooks, when used, are
under a lot of force. Always pull
the vehicle straight out. Never pull
on the hooks at a sideways angle.
The hooks could break off and
you or others could be injured
from the chain or cable
snapping back.Notice: Never use recovery
hooks to tow the vehicle.
Your vehicle could be damaged
and it would not be covered by
warranty.
For vehicles with recovery hooks at
the front of the vehicle, you can use
them if you are stuck off-road and
need to be pulled to some place
where you can continue driving.

Black plate (30,1)GMC Sierra Owner Manual - 2011
9-30 Driving and Operating
If you put things inside your
vehicle—like suitcases,
tools, packages, or anything
else —they go as fast as the
vehicle goes. If you have to
stop or turn quickly, or if there
is a crash, they will keep going.
{WARNING
Things you put inside the
vehicle can strike and injure
people in a sudden stop or
turn, or in a crash.
.Put things in the cargo
area of the vehicle. Try to
spread the weight evenly.
.Never stack heavier
things, like suitcases,
inside the vehicle so that
some of them are above
the tops of the seats.
(Continued)
WARNING (Continued)
.Do not leave an
unsecured child restraint
in the vehicle.
.When you carry something
inside the vehicle, secure
it whenever you can.
.Do not leave a seat folded
down unless you need to.
There is also important loading
information for off-road driving in
this manual. See “Loading Your
Vehicle for Off-Road Driving“
under Off-Road Driving on
page 9‑7. Two-Tiered Loading
Depending on the model of your
pick‐up, an upper load platform
can be created by positioning
three or four 5 cm (2 inches) by
15 cm (6 inches) wooden planks
across the width of the pickup
box. The planks must be
inserted in the pickup box
depressions.
When using this upper load
platform, be sure the load is
securely tied down to prevent it
from shifting. The load's center
of gravity should be positioned
in a zone over the rear axle.
The zone is located in the area
between the front of each wheel
well and the rear of each wheel
well. The center of gravity height
must not extend above the top
of the pickup box flareboard.

Black plate (34,1)GMC Sierra Owner Manual - 2011
9-34 Driving and Operating
When the truck‐camper is
loaded, drive to a scale and
weigh on the front and on the
rear wheels separately to
determine axle loads. Individual
axle loads should not exceed
either of the gross axle weight
ratings (GAWR). The total axle
loads should not exceed your
vehicle's gross vehicle weight
rating (GVWR). These ratings
are given on the vehicle
certification label attached to
the rear edge of the driver door.
See“Certification/Tire Label”
under Vehicle Load Limits on
page 9‑25. If weight ratings
are exceeded, move or remove
items to bring all weights below
the ratings.
See your dealer for more
information on curb weights,
cargo weights, Cargo Weight
Rating and the correct center
of gravity zone.Starting and
Operating
New Vehicle Break-In
Notice: The vehicle does not
need an elaborate break-in. But it
will perform better in the long run
if you follow these guidelines:
.Keep the vehicle speed at
88 km/h (55 mph) or less for
the first 805 km (500 miles).
.Do not drive at any one
constant speed, fast or
slow, for the first 805 km
(500 miles). Do not make
full-throttle starts. Avoid
downshifting to brake or
slow the vehicle.
.Avoid making hard stops for
the first 322 km (200 miles)
or so. During this time the
new brake linings are not
yet broken in. Hard stops
with new linings can mean
premature wear and earlier
replacement. Follow this
breaking-in guideline every
time you get new brake
linings.
.Do not tow a trailer during
break-in. See Trailer
Towing on page 9‑95 for the
trailer towing capabilities
of the vehicle and more
information.
Following break‐in, engine speed
and load can be gradually
increased.