296 VEHICLE CARE
.The tire has a bump, bulge,
or split.
.The tire has a puncture, cut,
or other damage that cannot
be repaired well because of the
size or location of the damage.
Tire Rotation
Tires should be rotated every
12 000 km (7,500 mi). See
Maintenance Schedule0332.
Tires are rotated to achieve a
more uniform wear for all tires.
The first rotation is the most
important.
Anytime unusual wear is noticed,
rotate the tires as soon as
possible, check for proper tire
inflation pressure, and check for
damaged tires or wheels. If the
unusual wear continues after the
rotation, check the wheel
alignment. See When It Is Time for
New Tires 0297 and
Wheel Replacement 0301.
Use this rotation pattern when
rotating the tires.
Do not include the compact spare
tire in the tire rotation.
Adjust the front and rear tires to
the recommended inflation
pressure on the Tire and Loading
Information label after the tires
have been rotated. See Tire
Pressure 0289 and
Vehicle Load Limits 0170.
Reset the Tire Pressure Monitor
System. See Tire Pressure Monitor
Operation 0292. Check that all wheel nuts are
properly tightened. See
“Wheel
Nut Torque ”under Capacities and
Specifications 0346, and
“Removing the Flat Tire and
Installing the Spare Tire ”under
Tire Changing 0310.
{Warning
Rust or dirt on a wheel, or on
the parts to which it is fastened,
can make wheel nuts become
loose after time. The wheel
could come off and cause a
crash. When changing a wheel,
remove any rust or dirt from
places where the wheel attaches
to the vehicle. In an emergency,
a cloth or a paper towel can be
used; however, use a scraper or
wire brush later to remove all
rust or dirt.
Lightly coat the inner diameter of
the wheel hub opening with wheel
bearing grease after a wheel
298 VEHICLE CARE
including brake system
performance, ride and handling,
traction control, and tire pressure
monitoring performance. GM's
TPC Spec number is molded onto
the tire's sidewall near the tire
size. If the tires have an all-season
tread design, the TPC Spec
number will be followed by MS for
mud and snow. SeeTire Sidewall
Labeling 0284.
GM recommends replacing worn
tires in complete sets of four.
Uniform tread depth on all tires
will help to maintain the
performance of the vehicle.
Braking and handling performance
may be adversely affected if all the
tires are not replaced at the same
time. If proper rotation and
maintenance have been done, all
four tires should wear out at
about the same time. See Tire
Rotation 0296. However, if it is
necessary to replace only one axle
set of worn tires, place the new
tires on the rear axle. Winter tires with the same speed
rating as the original equipment
tires may not be available for H, V,
W, Y and ZR speed rated tires.
Never exceed the winter tires’
maximum speed capability when
using winter tires with a lower
speed rating.
{Warning
Tires could explode during
improper service. Attempting to
mount or dismount a tire could
cause injury or death. Only your
dealer or authorized tire service
center should mount or
dismount the tires.
{Warning
Mixing tires of different sizes,
tread patterns, or types on the
same axle may cause loss of
control of the vehicle, resulting
(Continued)
Warning (Continued)
in a crash or other vehicle
damage. Use the same size, load
range, and type of tires as the
original tires.
{Warning
Using bias-ply tires on the
vehicle may cause the wheel rim
flanges to develop cracks after
many miles of driving. A tire
and/or wheel could fail suddenly
and cause a crash. Use only
radial-ply tires with the wheels
on the vehicle.
If the vehicle tires must be
replaced with a tire that does not
have a TPC Spec number, make
sure they are the same size, load
range, speed rating, and
construction (radial) as the
original tires.
VEHICLE CARE 299
Vehicles that have a tire pressure
monitoring system could give an
inaccurate low-pressure warning if
non-TPC Spec rated tires are
installed. SeeTire Pressure Monitor
System 0291.
The Tire and Loading Information
label indicates the original
equipment tires on the vehicle.
See Vehicle Load Limits 0170.
Different Size Tires and
Wheels
If wheels or tires are installed that are
a different size than the original
equipment wheels and tires, vehicle
performance, including its braking,
ride and handling characteristics,
stability, and resistance to rollover
may be affected. If the vehicle has
electronic systems such as antilock
brakes, rollover airbags, traction
control, electronic stability control,
or All-Wheel Drive, the performance
of these systems can also be affected.
{Warning
If different sized wheels are used,
there may not be an acceptable
level of performance and safety if
tires not recommended for those
wheels are selected. This increases
the chance of a crash and serious
injury. Only use GM specific wheel
and tire systems developed for the
vehicle, and have them properly
installed by a GM certified
technician.
See Buying New Tires 0297 and
Accessories and Modifications 0249.
Uniform Tire Quality
Grading
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 tires, compact 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.
Quality grades can be found where
applicable on the tire sidewall
between tread shoulder and
maximum section width. For
example:
300 VEHICLE CARE
Treadwear 200 Traction AA
Temperature A
All Passenger Car Tires Must
Conform to Federal Safety
Requirements In Addition To
These Grades.
Treadwear
The treadwear grade is a
comparative rating based on the
wear rate of the tire when tested
under controlled conditions on a
specified government test course.
For example, a tire graded
150 would wear one and one-half
(1½) 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 significantly from the norm
due to variations in driving habits,
service practices and differences
in road characteristics and
climate.Traction
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 specified
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.
Temperature
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
specified indoor laboratory test
wheel. Sustained high temperaturecan 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 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 inflated and not
overloaded. Excessive speed,
underinflation, 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 were aligned and
balanced at the factory to provide the
longest tire life and best overall
performance. Adjustments to wheel
VEHICLE CARE 301
alignment and tire balancing are not
necessary on a regular basis. Consider
an alignment check if there is unusual
tire wear or the vehicle is significantly
pulling to one side or the other. Some
slight pull to the left or right,
depending on the crown of the road
and/or other road surface variations
such as troughs or ruts, is normal.
If the vehicle is vibrating when driving
on a smooth road, the tires and
wheels may need to be rebalanced.
See your dealer for proper diagnosis.
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. Some aluminum wheels
can be repaired. See your dealer if any
of these conditions exist.
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 235/55R20 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
(Continued)
302 VEHICLE CARE
Warning (Continued)
traction device only if its
manufacturer recommends it for
the vehicle's tire size combination
and road conditions. Follow that
manufacturer's instructions. To
avoid vehicle damage, drive slow
and readjust or remove the traction
device if it contacts the vehicle. Do
not spin the wheels. If traction
devices are used, install them on
the front tires.
Caution
If the vehicle is equipped with a tire
size other than 235/55R20, use tire
chains only where legal and only
when necessary. Use low profile
chains that add no more than
12 mm thickness to the tire tread
and inner sidewall. Use chains that
are the proper size for the tires.
Install them on the tires of the(Continued)
Caution (Continued)
front axle. Do not use chains on the
tires of the rear 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.
If a Tire Goes Flat
It is unusual for a tire to blow out
while driving, especially if the tires are
maintained properly. See Tires0282.
If air goes out of a tire, it is much
more likely to leak out slowly. But if
there is ever a blowout, here are a few
tips about what to expect and what
to do:
If a front tire fails, the flat tire creates
a drag that pulls the vehicle toward
that side. Take your foot off the
accelerator pedal and grip the steering wheel firmly. Steer to maintain lane
position, and then gently brake to a
stop, well off the road, if possible.
A rear blowout, particularly on a
curve, acts much like a skid and may
require the same correction as used in
a skid. Stop pressing the accelerator
pedal and steer to straighten the
vehicle. It may be very bumpy and
noisy. Gently brake to a stop, well off
the road, if possible.
{Warning
Driving on a flat tire will cause
permanent damage to the tire.
Re-inflating a tire after it has been
driven on while severely
underinflated or flat may cause a
blowout and a serious crash. Never
attempt to re-inflate a tire that has
been driven on while severely
underinflated or flat. Have your
dealer or an authorized tire service
center repair or replace the flat tire
as soon as possible.
VEHICLE CARE 303
{Warning
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 flat
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
flat tire.
If a tire goes flat, avoid further tire
and wheel damage by driving slowly
to a level place, well off the road,
if possible. Turn on the hazard
warning flashers. See Hazard Warning
Flashers 0143.
{Warning
Changing a tire can be dangerous.
The vehicle can slip off the jack and
roll over or fall causing injury or
(Continued)
Warning (Continued)
death. Find a level place to change
the tire. To help prevent the vehicle
from moving:
1. Set the parking brake firmly.
2. Put an automatictransmission in P (Park) or a
manual transmission in
1 (First) or R (Reverse).
3. Turn off the engine and do not restart while the vehicle
is raised.
4. Do not allow passengers to remain in the vehicle.
5. Place wheel blocks, if equipped, on both sides of
the tire at the opposite corner
of the tire being changed.
This vehicle may come with a jack
and spare tire or a tire sealant and
compressor kit. To use the jacking
equipment to change a spare tire
safely, follow the instructions below.
Then see Tire Changing 0310. To use the tire sealant and compressor kit,
see
Tire Sealant and Compressor Kit
0 304.
When the vehicle has a flat tire (2),
use the following example as a guide
to assist you in the placement of
wheel blocks (1), if equipped.
1. Wheel Block (If Equipped)
2. Flat Tire
The following information explains
how to repair or change a tire.
304 VEHICLE CARE
Tire Sealant and
Compressor Kit
{Warning
Idling a vehicle in an enclosed area
with poor ventilation is dangerous.
Engine exhaust may enter the
vehicle. Engine exhaust contains
carbon monoxide (CO) which
cannot be seen or smelled. It can
cause unconsciousness and even
death. Never run the engine in an
enclosed area that has no fresh air
ventilation. For more information,
seeEngine Exhaust 0183.
{Warning
Overinflating a tire could cause the
tire to rupture and you or others
could be injured. Be sure to read
and follow the tire sealant and
compressor kit instructions and
(Continued)
Warning (Continued)
inflate the tire to its recommended
pressure. Do not exceed the
recommended pressure.
{Warning
Storing the tire sealant and
compressor kit or other equipment
in the passenger compartment of
the vehicle could cause injury. In a
sudden stop or collision, loose
equipment could strike someone.
Store the tire sealant and
compressor kit in its original
location.
If this vehicle has a tire sealant and
compressor kit, there may not be a
spare tire or tire changing equipment,
and on some vehicles there may not
be a place to store a tire. The tire sealant and compressor can
be used to temporarily seal punctures
up to 6 mm (0.25 in) in the tread area
of the tire. It can also be used to
inflate an underinflated tire.
If the tire has been separated from the
wheel, has damaged sidewalls, or has
a large puncture, the tire is too
severely damaged for the tire sealant
and compressor kit to be effective. See
Roadside Service
0353.
Read and follow all of the tire sealant
and compressor kit instructions.
The kit includes:
1. Sealant Canister Inlet Valve