CHEVROLET IMPALA 2002 8.G Owners Manual

6-42 Inflation -- Tire Pressure
The Tire-Loading Information label, which is on the
inside of the trunk lid, shows the correct inflation
pressures for your tires when they're cold. ªColdº
means your vehicle has been sitting for at least three
hours or driven no more than 1 mile (1.6 km).
NOTICE:
Don't let anyone tell you that underinflation or
overinflation is all right. It's not. If your tires
don't have enough air (underinflation), you
can get the following:

Too much flexing

Too much heat

Tire overloading

Bad wear

Bad handling

Bad fuel economy
NOTICE: (Continued)
NOTICE: (Continued)
If your tires have too much air (overinflation),
you can get the following:

Unusual wear

Bad handling

Rough ride

Needless damage from road hazards
When to Check
Check your tires once a month or more.
Don't forget your compact spare tire. It should be at
60 psi (420 kPa).
How to Check
Use a good quality pocket
-type gage to check tire
pressure. You can't tell if your tires are properly inflated
simply by looking at them. Radial tires may look
properly inflated even when they're underinflated.
Be sure to put the valve caps back on the valve stems.
They help prevent leaks by keeping out dirt and moisture.

6-43 Tire Inflation Monitor System
(If Equipped)
The tire inflation monitor system can alert you to a large
change in the pressure of one tire. The system ªlearnsº
the pressure at each tire throughout the operating speed
range of your vehicle. The system normally takes
between 45 and 90 minutes of driving to learn the tire
pressures. This time may be longer depending on your
individual driving habits. Learning need not be
accumulated during a single trip. Once learned, the
system will remember the tire pressures until the
system is recalibrated.
After the system has learned tire pressures with properly
inflated tires, the LOW TIRE PRESSURE message
will come on if the pressure in one tire becomes 12 psi
(83 kPa) lower than the other three tires. The tire
inflation monitor system won't alert you if the
pressure in more than one tire is low, if the system
is not properly calibrated, or if the vehicle is moving
faster than 70 mph (110 km/h).
The tire inflation monitor system detects differences
in tire rotation speeds that are caused by changes in
tire pressure. The system can alert you about a low
tire
-- but it doesn't replace normal tire maintenance.
See ªTiresº in the Index.When the LOW TIRE PRESSURE message comes on,
you should stop as soon as you can and check all your
tires for damage. (If a tire is flat, see ªIf a Tire Goes
Flatº in the Index.) Also check the tire pressure in all
four tires as soon as you can. See ªInflation
- Tire
Pressureº in the Index.
The LOW TIRE PRESSURE message will also be
displayed (while the ignition is on) until you reset
(calibrate) the system.
Don't reset the tire inflation monitor system without
first correcting the cause of the problem and checking
and adjusting the pressure in all four tires. If you reset
the system when the tire pressures are incorrect, the
system will not work properly and may not alert you
when a tire is low.
Any time you adjust a tire's pressure, rotate your tires,
or have one or more tires repaired or replaced, you'll
need to reset (calibrate) the tire inflation monitor
system. You'll also need to reset the system whenever
you buy new tires and whenever the vehicle's battery
has been disconnected.

6-44
To reset (calibrate) the system: The tire inflation
monitor system can be reset two ways. With the
ignition position at ON, pull the interior lamps
control to the ON and OFF settings three times.
It can also be reset through the radio using the
following steps:
1. Turn the ignition to ACC or ON and turn the
radio off.
2. Press and hold the TUNE DISP button on the radio for
at least five seconds until SETTINGS is displayed.
3. Press the SEEK PTYPE up or down arrow to scroll
through the main menu.
4. Scroll until TIRE MON appears on the display.
5. Press the 1 PREV or 2 NEXT button to enter the
submenu. RESET will be displayed.
6. Press the TUNE DISP button to reset. A chime will
be heard to verify the new setting and DONE will be
displayed for one second.
7. Once the monitor has been reset, scroll until EXIT
appears on the display.
8. Press the DISP button to exit programming. A chime
will be heard to verify exit.
The system completes the calibration process
during driving.The system normally takes 15 to 20 minutes of driving
in each of three speed ranges to ªlearnº tire pressures.
The speed ranges are 15 to 40 mph (25 to 65 km/h),
40 to 65 mph (65 to 105 km/h) and above 65 mph
(105 km/h). When learning is complete, the system
will alert you after two to eight minutes if a tire is 12 psi
(83 kPa) different from the other three tires. Detection
thresholds may be higher and detection times may be
longer on rough roads, curves and at high speeds. The
system is not capable of detection at speeds greater than
70 mph (110 km/h).
Tire Inspection and Rotation
Tires should be rotated every 6,000 to 8,000 miles
(10 000 to 13 000 km). Any time you notice unusual
wear, rotate your tires as soon as possible and check
wheel alignment. Also check for damaged tires or
wheels. See ªWhen It's Time for New Tiresº and
ªWheel Replacementº later in this section for
more information.
The purpose of regular rotation is to achieve more
uniform wear for all tires on the vehicle. The first
rotation is the most important. See ªScheduled
Maintenance Servicesº in the Index for scheduled
rotation intervals.

6-45
When rotating your tires, always use the correct rotation
pattern shown here.
Don't include the compact spare tire in your
tire rotation.
After the tires have been rotated, adjust the front and
rear inflation pressures as shown on the Tire
-Loading
Information label. Reset the tire inflation monitor.
See ªResetting the Tire Inflation Monitorº in the
Index. Make certain that all wheel nuts are properly
tightened. See ªWheel Nut Torqueº in the Index.
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
an accident. 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. See
ªChanging a Flat Tireº in the Index.

6-46
When It's Time for New Tires
One way to tell when it's
time for new tires is to
check the treadwear
indicators, which will
appear when your tires have
only 1/16 inch (1.6 mm) or
less of tread remaining.
You need a new tire if any of the following statements
are true:

You can see the indicators at three or more places
around the tire.

You can see cord or fabric showing through the
tire's rubber.

The tread or sidewall is cracked, cut or snagged deep
enough to show cord or fabric.
The tire has a bump, bulge or split.

The tire has a puncture, cut or other damage that
can't be repaired well because of the size or location
of the damage.
Buying New Tires
To find out what kind and size of tires you need, look at
the Tire
-Loading Information label.
The tires installed on your vehicle when it was new had
a Tire Performance Criteria Specification (TPC Spec)
number on each tire's sidewall. When you get new tires,
get ones with that same TPC Spec number. That way
your vehicle will continue to have tires that are designed
to give proper endurance, handling, speed rating,
traction, ride and other things during normal service on
your vehicle. If your tires have an all
-season tread
design, the TPC number will be followed by an ªMSº
(for mud and snow).
If you ever replace your tires with those not having
a TPC Spec number, make sure they are the same
size, load range, speed rating and construction type
(bias, bias
-belted or radial) as your original tires.

6-47
CAUTION:
Mixing tires could cause you to lose control
while driving. If you mix tires of different sizes
or types (radial and bias
-belted tires), the vehicle
may not handle properly, and you could have a
crash. Using tires of different sizes may also cause
damage to your vehicle. Be sure to use the same
size and type tires on all wheels.
It's all right to drive with your compact spare,
though. It was developed for use on your vehicle.
CAUTION:
If you use bias-ply tires on your vehicle, the
wheel rim flanges 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.
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, 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
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.

6-48
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
a half (1 1/2) 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
-- 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 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
-- 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 specified 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 inflated and
not overloaded. Excessive speed, underinflation, or
excessive loading, either separately or in combination,
can cause heat buildup and possible tire failure.

6-49 Wheel Alignment and Tire Balance
The wheels on your vehicle were aligned and balanced
carefully at the factory to give you the longest tire life
and best overall performance.
Scheduled wheel alignment and wheel balancing are
not needed. However, if you notice unusual tire wear or
your vehicle pulling one way or the other, the alignment
may need to be reset. If you notice your vehicle
vibrating when driving on a smooth road, your wheels
may need to be rebalanced.
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.

6-50
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.
See ªChanging a Flat Tireº in the Index for
more information.
Used Replacement Wheels
CAUTION:
Putting a used wheel on your vehicle is
dangerous. You can't know how it's been used
or how far it's 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
NOTICE:
Use tire chains only where legal and only when
you must. Use only SAE Class ªSº type chains
that are the proper size for your tires. Install
them on the front tires and 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.

6-51
Appearance Care
Remember, cleaning products can be hazardous. Some
are toxic. Others can burst into flame if you strike a
match or get them on a hot part of the vehicle. Some are
dangerous if you breathe their fumes in a closed space.
When you use anything from a container to clean your
vehicle, be sure to follow the manufacturer's warnings
and instructions. And always open your doors or
windows when you're cleaning the inside.
Never use these to clean your vehicle:

Gasoline

Benzene

Naphtha

Carbon Tetrachloride

Acetone

Paint Thinner

Turpentine

Lacquer Thinner

Nail Polish Remover
They can all be hazardous
-- some more than
others
-- and they can all damage your vehicle, too.Don't use any of these unless this manual says you can.
In many uses, these will damage your vehicle:

Alcohol

Laundry Soap

Bleach

Reducing Agents
Cleaning the Inside of Your Vehicle
Use a vacuum cleaner often to get rid of dust and loose
dirt. Wipe vinyl, leather, plastic and painted surfaces
with a clean, damp cloth.
Cleaning of Fabric/Carpet
Your dealer has cleaners for the cleaning of fabric and
carpet. They will clean normal spots and stains very
well. You can get GM
-approved cleaning products from
your dealer. See ªAppearance Care and Materialsº in
the Index.