ground clearance GMC SIERRA 2021 Owner's Manual

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Driving and Operating 215
2. Turn the steering wheel aboutone-eighth of a turn, until the right front
tire contacts the pavement edge.
3. Turn the steering wheel to go straight down the roadway.
Loss of Control
Skidding
There are three types of skids that
correspond to the vehicle's three control
systems:
.Braking Skid —wheels are not rolling.
.Steering or Cornering Skid —too much
speed or steering in a curve causes tires
to slip and lose cornering force.
.Acceleration Skid —too much throttle
causes the driving wheels to spin.
Defensive drivers avoid most skids by taking
reasonable care suited to existing conditions,
and by not overdriving those conditions. But
skids are always possible.
If the vehicle starts to slide, follow these
suggestions:
.Ease your foot off the accelerator pedal
and steer the way you want the vehicle
to go. The vehicle may straighten out. Be
ready for a second skid if it occurs.
.Slow down and adjust your driving
according to weather conditions. Stopping
distance can be longer and vehicle control
can be affected when traction is reduced
by water, snow, ice, gravel, or other
material on the road. Learn to recognize
warning clues —such as enough water,
ice, or packed snow on the road to make
a mirrored surface —and slow down
when you have any doubt.
.Try to avoid sudden steering, acceleration,
or braking, including reducing vehicle
speed by shifting to a lower gear. Any
sudden changes could cause the tires to
slide.
Remember: Antilock brakes help avoid only
the braking skid.
Off-Road Driving
Four-wheel-drive vehicles can be used for
off-road driving. Vehicles without four-wheel
drive and vehicles not equipped with All
Terrain (AT) or On-Off Road (OOR) tires must
not be driven off-road except on a level,
solid surface. For contact information about
the original equipment tires, see the
warranty manual.
One of the best ways for successful off-road
driving is to control the speed.
{Warning
When driving off-road, bouncing and
quick changes in direction can easily
throw you out of position. This could
cause you to lose control and crash. You
and your passengers should always wear
seat belts.
Before Driving Off-Road
.Have all necessary maintenance and
service work completed.
.Fuel the vehicle, fill fluid levels, and check
inflation pressure in all tires, including the
spare, if equipped.
.Read all the information about
four-wheel-drive vehicles in this manual.
.Remove any underbody air deflector,
if equipped. Re-attach the air deflector
after off-road driving.
.Know the local laws that apply to off-road
driving.
To gain more ground clearance if needed, it
may be necessary to remove the front fascia
lower air dam, if equipped. However, driving
without the air dam reduces fuel economy.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Driving and Operating 299
MeasurementHeight Example 1500 (mm)
H1 1 000
H2 1 050
H2−H1 50
(H2−H1)/2 25
H2−[(H2−H1)/2] 1 025
Tires
.Do not tow a trailer while using a
compact spare tire on the vehicle.
.Tires must be properly inflated to support
loads while towing a trailer. SeeTires
0 360 for instructions on proper tire
inflation.
Fifth-Wheel and Gooseneck Trailering
Fifth-wheel and gooseneck trailers can be
used with many pickup models. These
trailers place a larger percentage of the
weight (kingpin weight) on the tow vehicle
than conventional trailers. Make sure this
weight does not cause the vehicle to exceed
GAWR or GVWR. Fifth-wheel or gooseneck
kingpin weight should be 15–25% of the
trailer weight up to the maximum amount specified in the trailering chart for the
vehicle. See
“Trailer Weight" under Trailer
Towing 0293.
The hitch should be in the pickup bed so
that its centerline is over or slightly in front
of the rear axle. Take care that it is not so
far forward that it will contact the back of
the cab in sharp turns. This is especially
important for short box pickups. Trailer pin
box extensions and sliding fifth-wheel hitch
assemblies may be used. There should be at
least 15 cm (6 in) of clearance between the
top of the pickup box and the bottom of the
trailer shelf that extends over the box.
Make sure the hitch is attached to the tow
vehicle frame rails. Do not use the pickup
box for support.
Safety Chains
Always attach safety chains between the
vehicle and the trailer. Instructions about
safety chains may be provided by the hitch
manufacturer or by the trailer manufacturer.
If the trailer being towed weighs up to
2 271 kg (5,000 lb) with a factory-installed
step bumper, safety chains may be attached
to the attaching points on the bumper;
otherwise, safety chains should be attached
to holes on the trailer hitch.
Cross the safety chains under the tongue of
the trailer to help prevent the tongue from
contacting the road if it becomes separated
from the hitch. Always leave enough slack in
the safety chains to allow the combination
to turn. Never allow safety chains to drag
on the ground.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Vehicle Care 379
Your dealer will know the kind of wheel that
is needed.
Each new wheel should have the same
load-carrying capacity, diameter, width,
offset, and be mounted the same way as
the one it replaces.
Replace wheels, wheel bolts, wheel nuts,
or Tire Pressure Monitor System (TPMS)
sensors with new GM original equipment
parts.
{Warning
Using the wrong replacement wheels,
wheel bolts, or wheel nuts can be
dangerous. It could affect the braking and
handling of the vehicle. Tires can lose air,
and cause loss of control, causing a crash.
Always use the correct wheel, wheel
bolts, and wheel nuts for replacement.
Caution
The wrong wheel can also cause
problems with bearing life, brake cooling,
speedometer or odometer calibration,
headlamp aim, bumper height, vehicle
ground clearance, and tire or tire chain
clearance to the body and chassis.
Used Replacement Wheels
{Warning
Replacing a wheel with a used one is
dangerous. How it has been used or how
far it has been driven may be unknown.
It could fail suddenly and cause a crash.
When replacing wheels, use a new GM
original equipment wheel.
Tire Chains
{Warning
If the vehicle has 275/50R22, 275/60R20,
LT265/60R20, LT265/70R17, or LT275/65R18
size tires, do not use tire chains. There is
not enough clearance. Tire chains used on
a vehicle without the proper amount of
clearance can cause damage to the
brakes, suspension, or other vehicle parts.
The area damaged by the tire chains
could cause loss of control and a crash.
Use another type of traction device only
if its manufacturer recommends it for the
vehicle's tire size combination and road
conditions. Follow that manufacturer's(Continued)
Warning (Continued)
instructions. To avoid vehicle damage,
drive slow and readjust or remove the
traction device if it is contacting the
vehicle. Do not spin the wheels.
If traction devices are used, install them
on the rear tires.
Caution
If the vehicle is equipped with a tire size
other than 275/50R22, 275/60R20,
LT265/60R20, LT265/70R17, or LT275/65R18
use tire chains only where legal and only
when necessary. Use chains that are the
proper size for the tires. Install them on
the tires of the rear axle. Do not use
chains on the tires of the front axle.
Tighten them as tightly as possible with
the ends securely fastened. Drive slowly
and follow the chain manufacturer's
instructions. If the chains contact the
vehicle, stop and retighten them. If the
contact continues, slow down until it
stops. Driving too fast or spinning the
wheels with chains on will damage the
vehicle.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Vehicle Care 399
.Spray nozzle with a 40 degree wide angle
spray pattern or wider must be used.
.Nozzle must be kept at least 30 cm (1 ft)
away from all surfaces.
Automatic Car Wash
Caution
Some automatic car washes can cause
damage to the vehicle, wheels and
ground effects. Automatic car washes are
not recommended, due to lack of
clearance for the undercarriage and/or
wide rear tires and wheels.
Caution
Automatic car washes can cause damage
to the vehicle, wheels, ground effects,
and convertible top (if equipped).
Do not use automatic car washes due to
lack of clearance for the undercarriage,
wide rear tires, and wheels.
If using an automatic car wash, follow with
the car wash instructions. The windshield
wiper and rear window wiper, if equipped, must be turned off. Remove any accessories
that may be damaged or interfere with the
car wash equipment.
See
Power Assist Steps 030 for cleaning
information.
Rinse the vehicle well, before washing and
after, to remove all cleaning agents
completely. If they are allowed to dry on
the surface, they could stain.
Dry the finish with a soft, clean chamois or
an all-cotton towel to avoid surface
scratches and water spotting.
Finish Care
Application of aftermarket clearcoat sealant/
wax materials is not recommended.
If painted surfaces are damaged, see your
dealer to have the damage assessed and
repaired. Foreign materials such as calcium
chloride and other salts, ice melting agents,
road oil and tar, tree sap, bird droppings,
chemicals from industrial chimneys, etc., can
damage the vehicle's finish if they remain
on painted surfaces. Wash the vehicle as
soon as possible. If necessary, use
non-abrasive cleaners that are marked safe
for painted surfaces to remove foreign
matter. Occasional hand waxing or mild polishing
should be done to remove residue from the
paint finish. See your dealer for approved
cleaning products.
Do not apply waxes or polishes to uncoated
plastic, vinyl, rubber, decals, simulated
wood, or flat paint as damage can occur.
Caution
Machine compounding or aggressive
polishing on a basecoat/clearcoat paint
finish may damage it. Use only
non-abrasive waxes and polishes that are
made for a basecoat/clearcoat paint finish
on the vehicle.
To keep the paint finish looking new, keep
the vehicle garaged or covered whenever
possible.
Protecting Exterior Bright Metal Moldings
Caution
Failure to clean and protect the bright
metal moldings can result in a hazy
white finish or pitting. This damage
would not be covered by the vehicle
warranty.