VEHICLE CARE 287
Aspect Ratio:The relationship of
a tire's height to its width.
Belt
:A rubber coated layer of
cords between the plies and the
tread. Cords may be made from
steel or other reinforcing
materials.
Bead
:The tire bead contains steel
wires wrapped by steel cords that
hold the tire onto the rim.
Bias Ply Tire
:A pneumatic tire in
which the plies are laid at
alternate angles less than
90 degrees to the centerline of the
tread.
Cold Tire Pressure
:The amount
of air pressure in a tire, measured
in kPa (kilopascal) or psi (pounds
per square inch) before a tire has
built up heat from driving. See
Tire Pressure 0289.
Curb Weight
:The weight of a
motor vehicle with standard and
optional equipment including the maximum capacity of fuel, oil, and
coolant, but without passengers
and cargo.
DOT Markings
:A code molded
into the sidewall of a tire
signifying that the tire is in
compliance with the U.S.
Department of Transportation
(DOT) Motor Vehicle Safety
Standards. The DOT code includes
the Tire Identification Number
(TIN), an alphanumeric designator
which can also identify the tire
manufacturer, production plant,
brand, and date of production.
GVWR
:Gross Vehicle Weight
Rating. See Vehicle Load Limits
0 170.
GAWR FRT
:Gross Axle Weight
Rating for the front axle. See
Vehicle Load Limits 0170.
GAWR RR
:Gross Axle Weight
Rating for the rear axle. See
Vehicle Load Limits 0170. Intended Outboard Sidewall
:
The side of an asymmetrical tire
that must always face outward
when mounted on a vehicle.
Kilopascal (kPa)
:The metric unit
for air pressure.
Light Truck (LT-Metric) Tire
:A
tire used on light duty trucks and
some multipurpose passenger
vehicles.
Load Index
:An assigned number
ranging from 1 to 279 that
corresponds to the load carrying
capacity of a tire.
Maximum Inf lation Pressure
:
The maximum air pressure to
which a cold tire can be inflated.
The maximum air pressure is
molded onto the sidewall.
Maximum Load Rating
:The load
rating for a tire at the maximum
permissible inflation pressure for
that tire.
VEHICLE CARE 291
flange. It will read something like this:
Maximum load 690 kg (1,521 lbs)
300 kPa (44 psi) Max. Press.
Tire Pressure Monitor
System
The Tire Pressure Monitor System
(TPMS) uses radio and sensor
technology to check tire pressure
levels. The TPMS sensors monitor the
air pressure in your tires and transmit
tire pressure readings to a receiver
located in the vehicle.
Each tire, including the spare (if
provided), should be checked monthly
when cold and inflated to the
inflation pressure recommended by
the vehicle manufacturer on the
vehicle placard or tire inflation
pressure label. (If your vehicle has
tires of a different size than the size
indicated on the vehicle placard or tire
inflation pressure label, you should
determine the proper tire inflation
pressure for those tires.)
As an added safety feature, your
vehicle has been equipped with a tire
pressure monitoring system (TPMS)that illuminates a low tire pressure
telltale when one or more of your tires
is significantly under-inflated.
Accordingly, when the low tire
pressure telltale illuminates, you
should stop and check your tires as
soon as possible, and inflate them to
the proper pressure. Driving on a
significantly under-inflated tire causes
the tire to overheat and can lead to
tire failure. Under-inflation also
reduces fuel efficiency and tire tread
life, and may affect the vehicle's
handling and stopping ability.
Please note that the TPMS is not a
substitute for proper tire maintenance,
and it is the driver's responsibility to
maintain correct tire pressure, even if
under-inflation has not reached the
level to trigger illumination of the
TPMS low tire pressure telltale.
Your vehicle has also been equipped
with a TPMS malfunction indicator to
indicate when the system is not
operating properly. The TPMS
malfunction indicator is combined
with the low tire pressure telltale.
When the system detects a
malfunction, the telltale will flash forapproximately one minute and then
remain continuously illuminated. This
sequence will continue upon
subsequent vehicle start-ups as long
as the malfunction exists.
When the malfunction indicator is
illuminated, the system may not be
able to detect or signal low tire
pressure as intended. TPMS
malfunctions may occur for a variety
of reasons, including the installation
of replacement or alternate tires or
wheels on the vehicle that prevent the
TPMS from functioning properly.
Always check the TPMS malfunction
telltale after replacing one or more
tires or wheels on your vehicle to
ensure that the replacement or
alternate tires and wheels allow the
TPMS to continue to function
properly.
See
Tire Pressure Monitor Operation
0 292.
See Radio Frequency Statement 0358.
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
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 311
4. Turn the wing nut (4)counterclockwise to remove the
jack (1), wheel wrench (2), and
strap (3). Place the tool container
near the tire being changed.5. Remove the nut retaining thespare tire.
6. Remove the spare tire and place it next to the tire being changed.
Removing the Flat Tire and
Installing the Spare Tire
1. Do a safety check beforeproceeding. See If a Tire Goes Flat
0 302.
2. Turn the wheel wrench
counterclockwise to loosen all
the wheel nuts, but do not
remove them yet.
3. Place the jack near the flat tire.
Caution
Make sure that the jack lift head is
in the correct position or you may
damage your vehicle. The repairs
would not be covered by your
warranty.
316 VEHICLE CARE
standard tire repaired or replaced as
soon as convenient and return the
spare tire to the storage area.
When using a compact spare tire, the
AWD (if equipped), ABS, and Traction
Control systems may engage until the
spare tire is recognized by the vehicle,
especially on slippery roads. Adjust
driving to reduce possible wheel slip.
Caution
When the compact spare is
installed, do not take the vehicle
through an automatic car wash
with guide rails. The compact spare
can get caught on the rails which
can damage the tire, wheel, and
other parts of the vehicle.
Do not use the compact spare on
other vehicles.
Do not mix the compact spare tire or
wheel with other wheels or tires. They
will not fit. Keep the spare tire and its
wheel together.
Caution
Tire chains will not fit the compact
spare. Using them can damage the
vehicle and the chains. Do not use
tire chains on the compact spare.
Jump Starting
Jump Starting - North
America
For more information about the
vehicle battery, see Battery - North
America 0268.
If the battery has run down, try to use
another vehicle and some jumper
cables to start your vehicle. Be sure to
use the following steps to do it safely.
{Warning
WARNING: Battery posts,
terminals, and related accessories
contain lead and lead compounds,
chemicals known to the State of
California to cause cancer and birth
defects or other reproductive harm.
Batteries also contain other
chemicals known to the State of
California to cause cancer. WASH
HANDS AFTER HANDLING. For
more information go to
www.P65Warnings.ca.gov/
passenger-vehicle.
VEHICLE CARE 329
Cleaning High Gloss Surfaces
and Vehicle Information and
Radio Displays
Use a microfiber cloth on high gloss
surfaces or vehicle displays. First, use
a soft bristle brush to remove dirt that
can scratch the surface. Then gently
clean by rubbing with a microfiber
cloth. Never use window cleaners or
solvents. Periodically hand wash the
microfiber cloth separately, using mild
soap. Do not use bleach or fabric
softener. Rinse thoroughly and air dry
before next use.
Caution
Do not attach a device with a
suction cup to the display. This may
cause damage and would not be
covered by the vehicle warranty.
Instrument Panel, Leather, Vinyl,
Other Plastic Surfaces, Low
Gloss Paint Surfaces, and
Natural Open Pore Wood
Surfaces
Use a soft microfiber cloth dampened
with water to remove dust and loose
dirt. For a more thorough cleaning,
use a soft microfiber cloth dampened
with a mild soap solution.
Caution
Soaking or saturating leather,
especially perforated leather, as well
as other interior surfaces, may
cause permanent damage. Wipe
excess moisture from these surfaces
after cleaning and allow them to
dry naturally. Never use heat,
steam, or spot removers. Do not use
cleaners that contain silicone or
wax-based products. Cleaners
containing these solvents can
permanently change the appearance
and feel of leather or soft trim, and
are not recommended.Do not use cleaners that increase
gloss, especially on the instrument
panel. Reflected glare can decrease
visibility through the windshield
under certain conditions.
Caution
Use of air fresheners may cause
permanent damage to plastics and
painted surfaces. If an air freshener
comes in contact with any plastic
or painted surface in the vehicle,
blot immediately and clean with a
soft cloth dampened with a mild
soap solution. Damage caused by
air fresheners would not be covered
by the vehicle warranty.
Cargo Cover and
Convenience Net
If equipped, wash with warm water
and mild detergent. Do not use
chlorine bleach. Rinse with cold water,
and then dry completely.
Care of Seat Belts
Keep belts clean and dry.