Page 297 of 382

Vehicles equipped with 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 5-52.
Your vehicle’s original equipment
tires are listed on the Tire and
Loading Information Label.
SeeLoading the Vehicle
on page 4-35, 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
speci c wheel and tire systems
developed for your vehicle, and
have them properly installed by a
GM certi ed technician.
SeeBuying New Tires on page 5-59
andAccessories and Modifications
on page 5-3for additional
information.
Service and Appearance Care 5-61
Page 298 of 382

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 speci ed
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 signi cantly 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
speci ed government test
surfaces of asphalt and
concrete. A tire marked C may
have poor traction performance.
5-62 Service and Appearance Care
Page 299 of 382

{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.
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 speci ed 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 in ated and
not overloaded. Excessive
speed, underin ation, 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 might need to
be checked. If you notice your
vehicle vibrating when driving on a
smooth road, the tires and wheels
might need to be rebalanced.
See your dealer/retailer for
proper diagnosis.
Service and Appearance Care 5-63
Page 300 of 382

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/retailer if any of these
conditions exist.
Your dealer/retailer 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, wheel nuts,
or Tire Pressure Monitor System
(TPMS) sensors, replace them only
with new GM original equipment
parts. This way, you will be sure
to have the right wheel, wheel bolts,
wheel nuts, and TPMS sensors
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.
SeeChanging a Flat Tire on
page 5-66for more information.
Used Replacement Wheels
{CAUTION
Putting a used wheel on the
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.
5-64 Service and Appearance Care
Page 301 of 382

Tire Chains
{CAUTION
If your vehicle has LT285/75R16
or P265/65R18 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.
(Continued)
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 has a
tire size other than LT285/75R16
or P265/65R18 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.
Service and Appearance Care 5-65
Page 302 of 382

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
creates 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.
If a jack is provided with the
vehicle, it 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. If a jack
is provided with the vehicle, only
use it 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 3-5.
{CAUTION
Changing a tire can be dangerous.
The vehicle can slip off the jack
and roll over or fall on you or other
people. You and they could be
badly injured or even killed.
Find a level place to change your
tire. To help prevent the vehicle
from moving:
1. Set the parking brake rmly.
2. Put the shift lever in
P (Park).
(Continued)
5-66 Service and Appearance Care
Page 303 of 382

CAUTION (Continued)
3. If you have a
four-wheel-drive vehicle,
be sure the transfer case
is in a drive gear – not in
N (Neutral).
4. Turn off the engine and do
not restart while the vehicle
is raised.
5. Do not allow passengers to
remain in the vehicle.
To be even more certain the
vehicle will not move, put blocks
at the front and rear of the tire
farthest away from the one being
changed. That would be the tire
on the other side, at the opposite
end of the vehicle.When the vehicle has a at tire,
the wheel blocks need to be set up
before changing it. The wheel
blocks are located in the tool bag in
the swing-gate for H3 models or
below the rear seat for H3T models.
SeeRemoving the Spare Tire
and Tools (H3) on page 5-68or
Removing the Spare Tire and
Tools (H3T) on page 5-69for
more information.
To use the wheel blocks, lift the
wheel block and lock it into place.Use the following example as a
guide to assist in the placement of
the wheel blocks (A) when the
vehicle has a at tire (B).
A. Wheel Block
B. Flat Tire
The following information explains
how to use the jack and change
a tire.
Service and Appearance Care 5-67
Page 304 of 382

Removing the Spare Tire
and Tools (H3)
The equipment needed is located in
the swing-gate, behind a cover.
To remove the equipment:
1. Open the swing-gate.
SeeSwing-gate on page 2-9.
2. Remove the cover, located on
the inside of the swing-gate,
by lifting the two latches.
3. Turn the wing nut
counterclockwise to release
the jack tool bag and jack
and remove them.4. Undo the straps that secure the
jack tool bag to the jack.
5. Open the tool bag to nd the
following tools, which are
used to remove the spare tire
and at tire:
A. Wheel Wrench
B. Jack Handle Extensions
C. Jack Handle
D. Jack
E. Wheel BlocksThe spare tire is attached to the
outside of the swing-gate.
To remove the spare tire:
1. If the vehicle has a spare tire
cover release the latch by
pulling the latch straight back
and turning it away from
the cover at the same time.
Notice:Opening the endgate
before completely closing and
latching the spare tire cover may
result in damage to your vehicle.
Close and latch the spare tire
cover before opening the endgate
to avoid possible damage.
5-68 Service and Appearance Care