
Different Size Tires and Wheels
If you add wheels or tires that are a different size
than your original equipment wheels and tires,
this may 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, 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 394and
Accessories and Modi cations on page 319
for additional information.
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.
396

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.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.
397

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.
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.
398

{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 clearance to the body
and chassis.
{CAUTION:
Rust or dirt on a wheel, or on the parts to
which it is fastened, can make wheel nuts
become loose after a time. The wheel could
come off and cause a crash. When you
change a wheel, remove any rust or dirt
from places where the wheel attaches to
the vehicle. In an emergency, you can use
a cloth or a paper towel to do this; but be
sure to use a scraper or wire brush later,
if you need to, to get all the rust or dirt off.
{CAUTION:
Never use oil or grease on studs or the
threads of the wheel nuts. If you do, the
wheel nuts might come loose and the
wheel could fall off, causing a crash.
399

Tightening Wheel Lug Nuts
{CAUTION:
Incorrect wheel nuts or improperly
tightened wheel nuts can cause the wheel
to become loose and even come off.
This could lead to a crash. Be sure to
use the correct wheel nuts. If you have
to replace them, be sure to get new GM
original equipment wheel nuts.
Notice:Improperly tightened wheel nuts can
lead to brake pulsation and rotor damage.
To avoid expensive brake repairs, evenly
tighten the wheel nuts in the proper sequence
and to the proper torque speci cation.Tighten the wheel
lug nuts rmly in a
crisscross sequence
as shown.
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.
400

Tire Chains
{CAUTION:
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 you to lose control
of your vehicle and you or others
may be injured in a crash.
CAUTION: (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, re-adjust or remove the
device if it is contacting your vehicle,
and do not spin your wheels. If you
do nd traction devices that will t,
install them on the rear tires.
401

Lifting Your Vehicle
{CAUTION:
Lifting a vehicle can cause an injury.
The vehicle can slip off the jack and roll
over you or other people. You and they
could be badly injured. Find a level place
to lift your vehicle. To help prevent the
vehicle from moving:
1. Set the parking brake rmly.
2. Put an automatic transmission
shift lever in PARK (P), or shift a
manual transmission to FIRST (1)
or REVERSE (R).
3. Turn off the engine.
To be even more certain the vehicle
won’t move, you can put blocks in
front of and behind the wheels.
{CAUTION:
Getting under a vehicle when it is jacked
up is dangerous. If the vehicle slips off
the jack, you could be badly injured or
killed. Never get under a vehicle when it
is supported only by a jack.
{CAUTION:
Raising your vehicle with the jack
improperly positioned can damage the
vehicle and even make the vehicle fall.
To help avoid personal injury and vehicle
damage, be sure to place the jack in the
proper location before raising the vehicle.
402