2000 PONTIAC BONNEVILLE tires

6-34
If your vehicle is damaged in an accident, the headlamp
aim may be affected. Aim adjustment to the low beam
may be necessary if it is difficult to see lane markers
(for horizontal aim), or if oncoming drivers flash their
high beams at you (for vertical aim). If you believe your
headlamps need to be re
-aimed, we recommend that you
take your vehicle to your dealer for service. However, it
is possible for you to re
-aim your headlamps as
described in the following procedure.
NOTICE:
To make sure your headlamps are aimed
properly, read all the instructions before
beginning. Failure to follow these instructions
could cause damage to headlamp parts.
The vehicle should be properly prepared as follows:

The vehicle should be placed so the headlamps are
25 ft. (7.6 m) from a light colored wall or other
flat surface.
The vehicle must have all four tires on a perfectly
level surface which is level all the way to the wall or
other flat surface.

The vehicle should be placed so it is perpendicular to
the wall or other flat surface.

The vehicle should not have any snow, ice or mud
attached to it.

The vehicle should be fully assembled and all other
work stopped while headlamp aiming is being done.

The vehicle should be normally loaded with a full
tank of fuel and one person or 160 lbs. (75 kg) on the
driver's seat.

Tires should be properly inflated.
Headlamp aiming is done with the vehicle low beam
lamps. The high beam lamps will be correctly aimed if
the low beam lamps are aimed properly.
The headlamp aiming devices are under the hood near
the headlamps.

6-42
Tires
Your new vehicle comes with high-quality tires made by
a leading tire manufacturer. If you ever have questions
about your tire warranty and where to obtain service,
see your Pontiac Warranty booklet for details.
CAUTION:
Poorly maintained and improperly used tires
are dangerous.

Overloading your tires can cause
overheating as a result of too much friction.
You could have an air
-out and a serious
accident. See ªLoading Your Vehicleº in
the Index.
CAUTION: (Continued)
CAUTION: (Continued)

Underinflated tires pose the same danger as
overloaded tires. The resulting accident
could cause serious injury. Check all tires
frequently to maintain the recommended
pressure. Tire pressure should be checked
when your tires are cold.

Overinflated tires are more likely to be
cut, punctured or broken by a sudden
impact
-- such as when you hit a pothole.
Keep tires at the recommended pressure.

Worn, old tires can cause accidents. If your
tread is badly worn, or if your tires have
been damaged, replace them.
Inflation -- Tire Pressure
The Tire-Loading Information label, which is on the
rear edge of the driver's door, 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).

6-43
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.
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.
Check Tire Pressure System
The check tire pressure system can alert you to a large
change in the pressure of one tire. The system won't
alert you before you drive that a tire is low or flat.
You must begin driving before the system will
work properly.

6-44
The CHECK TIRE PRESSURE message will appear on
the Driver Information Center (DIC) and the systems
monitor TIRE PRESS light will come on if pressure
difference (low pressure) is detected in one tire. The
check tire pressure system may not alert you if:

more than one tire is low,

the vehicle is moving faster than 65 mph (105 km/h),

the system is not yet calibrated,

the tire treadwear is uneven,

the compact spare tire is installed,

tire chains are being used, or

the vehicle is being driven on a rough or frozen road.
If the anti
-lock brake system warning light comes on,
the check tire pressure system may not be working
properly. See your dealer for service. (Also, see
ªAnti
-Lock Brake System Warning Lightº in the Index.)
The check tire pressure 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 CHECK TIRE PRESSURE message appears
on the Driver Information Center and the systems
monitor TIRE PRESS light 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.
Any time you adjust a tire's pressure or have one or
more tires repaired or replaced, you'll need to reset
(calibrate) the check tire pressure system. You'll also
need to reset the system whenever you rotate the tires,
buy new tires, install or remove the compact spare, and
whenever the vehicle's battery has been disconnected.
Don't reset the check tire pressure 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 check
tire pressure system will not work properly and may not
alert you when a tire is low or high.
To reset (calibrate) the system:
1. Turn the ignition switch to RUN.
2. Using the MODE and SELECT buttons, change the
DIC to display TIRE PRESSURE.
3. Press and hold the RESET button for about five seconds.

6-45
4. The display should change to read TIRE PRESSURE
RESET. If TIRE PRESSURE RESET does not
appear on the display after about five seconds,
see your dealer for service.
5. When you release the button after seeing the TIRE
PRESSURE RESET message, the display will
change to read TIRE PRESSURE NORMAL.
To reset (calibrate) the system with a systems monitor:

Turn the ignition switch to RUN.

Press and hold the TIRE PRESS RESET button for
about five seconds.

The TIRE PRESS light on the systems monitor
should begin to flash. If the TIRE PRESS light does
not begin to flash after about five seconds, see your
dealer for service.

Release the TIRE PRESS RESET button and the
system should reset (the TIRE PRESS telltale light
goes out).
The system completes the calibration process during
driving. Calibration time can take 45 to 90 minutes,
depending on your driving habits. After the system
has been calibrated, the system will alert the driver
that a tire is low, up to a maximum speed of
65 mph (105 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.
When rotating your tires, always use the correct rotation
pattern shown here.

6-46
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 Check Tire Pressure
System. See ªCheck Tire Pressure Systemº 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.)
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.

6-47 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.
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.

6-48 Uniform Tire Quality Grading
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.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.