2007 GMC SIERRA Owner's Manual

{CAUTION:
Mixing tires could cause you to lose
control while driving. If you mix tires of
different sizes, brands, or types (radial
and bias-belted tires), the vehicle may not
handle properly, and you could have a
crash. Using tires of different sizes,
brands or types may also cause damage
to your vehicle. Be sure to use the same
size, brand, and type tires on all wheels.
Your vehicle may have a different size
spare than the road tires (those originally
installed on your vehicle). When new, your
vehicle included a spare tire and wheel
assembly with a similar overall diameter
as your vehicle’s road tires and wheels,
so it is all right to drive on it. Because
this spare was developed for use on your
vehicle, it will not affect vehicle handling.
{CAUTION:
If you use bias-ply tires on your vehicle,
the wheel rim anges could develop
cracks after many miles of driving. A tire
and/or wheel could fail suddenly, causing
a crash. Use only radial-ply tires with the
wheels on your vehicle.
If you must replace your vehicle’s tires with those
that do not have a TPC Spec number, make
sure they are the same size, load range, speed
rating, and construction type (radial and
bias-belted tires) as your vehicle’s original tires.
Vehicles that have a tire pressure monitoring
system may give an inaccurate low-pressure
warning if non-TPC spec rated tires are installed
on your vehicle. Non-TPC Spec rated tires
may give a low-pressure warning that is higher or
lower than the proper warning level you would
get with TPC Spec rated tires. SeeTire Pressure
Monitor System on page 561.
569

Your vehicle’s original equipment tires are listed
on the Tire and Loading Information Label.
This label is attached to the vehicle’s center pillar
(B-pillar). SeeLoading Your Vehicle on page 425,
for more information about the Tire and Loading
Information Label and its location on your vehicle.
Different Size Tires and Wheels
If you add wheels or tires that are a different size
than your original equipment wheels and tires,
this could affect the way your vehicle performs,
including its braking, ride and handling
characteristics, stability, and resistance to rollover.
Additionally, if your vehicle has electronic
systems such as anti-lock brakes, rollover airbags,
traction control, and electronic stability control,
the performance of these systems can be affected.
{CAUTION:
If you add different sized wheels, your
vehicle may not provide an acceptable
level of performance and safety if tires not
recommended for those wheels are
selected. You may increase the chance
that you will crash and suffer serious
injury. Only use GM specic wheel and
tire systems developed for your vehicle,
and have them properly installed by a GM
certied technician.
SeeBuying New Tires on page 568and
Accessories and Modications on page 486for
additional information.
570

Uniform Tire Quality Grading
Quality grades can be found where applicable on
the tire sidewall between tread shoulder and
maximum section width. For example:
Treadwear 200 Traction AA Temperature A
The following information relates to the system
developed by the United States National Highway
Traffic Safety Administration (NHTSA), which
grades tires by treadwear, traction, and
temperature performance. This applies only to
vehicles sold in the United States. The grades are
molded on the sidewalls of most passenger car
tires. The Uniform Tire Quality Grading (UTQG)
system does not apply to deep tread, winter-type
snow tires, space-saver, or temporary use
spare tires, tires with nominal rim diameters of
10 to 12 inches (25 to 30 cm), or to some
limited-production tires.
While the tires available on General Motors
passenger cars and light trucks may vary with
respect to these grades, they must also conform
to federal safety requirements and additional
General Motors Tire Performance Criteria (TPC)
standards.
Treadwear
The treadwear grade is a comparative rating
based on the wear rate of the tire when tested
under controlled conditions on a specied
government test course. For example, a tire
graded 150 would wear one and a half (1.5) times
as well on the government course as a tire
graded 100. The relative performance of tires
depends upon the actual conditions of their use,
however, and may depart signicantly from
the norm due to variations in driving habits, service
practices, and differences in road characteristics
and climate.
Traction – AA, A, B, C
The traction grades, from highest to lowest, are
AA, A, B, and C. Those grades represent the tire’s
ability to stop on wet pavement as measured
under controlled conditions on specied
government test surfaces of asphalt and concrete.
A tire marked C may have poor traction
performance.
Warning:The traction grade assigned to this tire
is based on straight-ahead braking traction
tests, and does not include acceleration, cornering,
hydroplaning, or peak traction characteristics.
571

Temperature – A, B, C
The temperature grades are A (the highest), B,
and C, representing the tire’s resistance to
the generation of heat and its ability to dissipate
heat when tested under controlled conditions on a
specied indoor laboratory test wheel. Sustained
high temperature can cause the material of the tire
to degenerate and reduce tire life, and excessive
temperature can lead to sudden tire failure.
The grade C corresponds to a level of performance
which all passenger car tires must meet under
the Federal Motor Vehicle Safety Standard
No. 109. Grades B and A represent higher levels
of performance on the laboratory test wheel
than the minimum required by law.
Warning:The temperature grade for this tire is
established for a tire that is properly inated
and not overloaded. Excessive speed,
under-ination, or excessive loading, either
separately or in combination, can cause heat
buildup and possible tire failure.
Wheel Alignment and Tire Balance
The tires and wheels on your vehicle were aligned
and balanced carefully at the factory to give you
the longest tire life and best overall performance.
Adjustments to wheel alignment and tire
balancing will not be necessary on a regular basis.
However, if you notice unusual tire wear or your
vehicle pulling to one side or the other, the
alignment may need to be checked. If you notice
your vehicle vibrating when driving on a smooth
road, your tires and wheels may need to be
rebalanced. See your dealer/retailer for proper
diagnosis.
572

Wheel Replacement
Replace any wheel that is bent, cracked, or badly
rusted or corroded. If wheel nuts keep coming
loose, the wheel, wheel bolts and wheel nuts
should be replaced. If the wheel leaks air, replace
it (except some aluminum wheels, which can
sometimes be repaired). See your dealer if any of
these conditions exist.
Your dealer will know the kind of wheel you need.
Each new wheel should have the same
load-carrying capacity, diameter, width, offset
and be mounted the same way as the one
it replaces.
If you need to replace any of your wheels, wheel
bolts or wheel nuts, replace them only with
new GM original equipment parts. This way, you
will be sure to have the right wheel, wheel
bolts and wheel nuts for your vehicle.{CAUTION:
Using the wrong replacement wheels,
wheel bolts, or wheel nuts on your vehicle
can be dangerous. It could affect the
braking and handling of your vehicle,
make your tires lose air and make you
lose control. You could have a collision in
which you or others could be injured.
Always use the correct wheel, wheel bolts,
and wheel nuts for replacement.
Notice: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.
573

Whenever a wheel, wheel bolt or wheel nut is
replaced on a dual wheel setup, check the wheel
nut torque after 100, 1,000 and 6,000 miles
(160, 1 600 and 10 000 km) of driving. For proper
torque, see “Wheel Nut Torque” underCapacities
and Specications on page 616.
SeeChanging a Flat Tire on page 576for more
information.
Used Replacement Wheels
{CAUTION:
Putting a used wheel on your vehicle is
dangerous. You cannot know how it has
been used or how far it has been driven. It
could fail suddenly and cause a crash. If
you have to replace a wheel, use a new
GM original equipment wheel.
Tire Chains
{CAUTION:
If your vehicle has dual wheels or
P265/65R18, P275/55R20 or LT265/70R17
size tires, do not use tire chains. They can
damage your vehicle because 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 you to lose control of
your vehicle and you or others may be
injured in a crash.
CAUTION: (Continued)
574

CAUTION: (Continued)
Use another type of traction device only if
its manufacturer recommends it for use
on your vehicle and tire size combination
and road conditions. Follow that
manufacturer’s instructions. To help avoid
damage to your vehicle, drive slowly,
readjust, or remove the device if it is
contacting your vehicle, and do not spin
your vehicle’s wheels.
If you do nd traction devices that will t,
install them on the rear tires.Notice:If your vehicle does not have dual
wheels and has a tire size other than
P265/65R18, P275/55R20 or LT265/70R17, use
tire chains only where legal and only when
you must. Use chains that are the proper size
for your 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 you can hear the chains
contacting your 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 your
vehicle.
575

If a Tire Goes Flat
It is unusual for a tire to blowout while you are
driving, especially if you maintain your vehicle’s
tires properly. If air goes out of a tire, it is
much more likely to leak out slowly. But if you
should ever have a blowout, here are a few tips
about what to expect and what to do:
If a front tire fails, the at tire will create a drag
that pulls the vehicle toward that side. Take your
foot off the accelerator pedal and grip the
steering wheel rmly. Steer to maintain lane
position, and then gently brake to a stop well out
of the traffic lane.
A rear blowout, particularly on a curve, acts much
like a skid and may require the same correction
you would use in a skid. In any rear blowout
remove your foot from the accelerator pedal. Get
the vehicle under control by steering the way
you want the vehicle to go. It may be very bumpy
and noisy, but you can still steer. Gently brake
to a stop, well off the road if possible.{CAUTION:
Lifting a vehicle and getting under it to do
maintenance or repairs is dangerous
without the appropriate safety equipment
and training. The jack provided with your
vehicle is designed only for changing a
at tire. If it is used for anything else, you
or others could be badly injured or killed
if the vehicle slips off the jack. Use the
jack provided with your vehicle only for
changing a at tire.
If a tire goes at, the next part shows how to use
the jacking equipment to change a at tire safely.
Changing a Flat Tire
If a tire goes at, avoid further tire and wheel
damage by driving slowly to a level place. Turn on
your hazard warning ashers. SeeHazard
Warning Flashers on page 211for more
information.
576