2005 PONTIAC BONNEVILLE Owners Manual

Tire Size
The following illustration shows an example of a typical
passenger vehicle tire size.
(A) Passenger (P-Metric) Tire:The United States
version of a metric tire sizing system. The letter P as the
rst character in the tire size means a passenger
vehicle tire engineered to standards set by the U.S. Tire
and Rim Association.
(B) Tire Width:The three-digit number indicates the
tire section width in millimeters from sidewall to sidewall.
(C) Aspect Ratio:A two-digit number that indicates
the tire height-to-width measurements. For example, if
the tire size aspect ratio is 60, as shown in item C of the
illustration, it would mean that the tire’s sidewall is
60 percent as high as it is wide.(D) Construction Code:A letter code is used to
indicate the type of ply construction in the tire. The letter
R means radial ply construction; the letter D means
diagonal or bias ply construction; and the letter B means
belted-bias ply construction.
(E) Rim Diameter:Diameter of the wheel in inches.
(F) Service Description:These characters represent
the load range and speed rating of the tire. The load
index represents the load carry capacity a tire is certied
to carry. The load index can range from 1 to 279. The
speed rating is the maximum speed a tire is certied
to carry a load. Speed ratings range from A to Z.
Tire Terminology and Denitions
Air Pressure:The amount of air inside the tire pressing
outward on each square inch of the tire. Air pressure
is expressed in pounds per square inch (psi) or
kiloPascal (kPa).
Accessory Weight:This means the combined weight
of optional accessories. Some examples of optional
accessories are, automatic transmission, power steering,
power brakes, power windows, power seats, and air
conditioning.
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Aspect Ratio:The relationship of a tire’s height to
its width.
Belt:A rubber coated layer of cords that is located
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 Ination Pressure:The amount of air pressure in
a tire, measured in pounds per square inch (psi) or
kilopascals (kPa) before a tire has built up heat
from driving. SeeInation - Tire Pressure on page 5-80.
Curb Weight:This means 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
Identication Number (TIN), an alphanumeric designator
which can also identify the tire manufacturer, production
plant, brand and date of production.
GVWR:Gross Vehicle Weight Rating, seeLoading
Your Vehicle on page 4-29.
GAWR FRT:Gross Axle Weight Rating for the front
axle, seeLoading Your Vehicle on page 4-29.
GAWR RR:Gross Axle Weight Rating for the rear axle,
seeLoading Your Vehicle on page 4-29.
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.
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Load Index:An assigned number ranging from
1 to 279 that corresponds to the load carrying capacity
of a tire.
Maximum Ination Pressure:The maximum air
pressure to which a cold tire may be inated. The
maximum air pressure is molded onto the sidewall.
Maximum Load Rating:The load rating for a tire at the
maximum permissible ination pressure for that tire.
Maximum Loaded Vehicle Weight:The sum of curb
weight; accessory weight; vehicle capacity weight;
and production options weight.
Normal Occupant Weight:The number of occupants a
vehicle is designed to seat multiplied by 150 lbs (68 kg).
SeeLoading Your Vehicle on page 4-29.
Occupant Distribution:Designated seating positions.
Outward Facing Sidewall:The side of an
asymmetrical tire that has a particular side that faces
outward when mounted on a vehicle. The side of the tire
that contains a whitewall, bears white lettering or
bears manufacturer, brand, and/or model name molding
that is higher or deeper than the same moldings on
the other sidewall of the tire.Passenger (P-Metric) Tire:A tire used on passenger
cars and some light duty trucks and multipurpose
vehicles.
Recommended Ination Pressure:Vehicle
manufacturer’s recommended tire ination pressure and
shown on the tire placard. SeeInation - Tire Pressure
on page 5-80andLoading Your Vehicle on page 4-29.
Radial Ply Tire:A pneumatic tire in which the ply cords
that extend to the beads are laid at 90 degrees to the
centerline of the tread.
Rim:A metal support for a tire and upon which the tire
beads are seated.
Sidewall:The portion of a tire between the tread and
the bead.
Speed Rating:An alphanumeric code assigned to a
tire indicating the maximum speed at which a tire
can operate.
Traction:The friction between the tire and the road
surface. The amount of grip provided.
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Tread:The portion of a tire that comes into contact
with the road.
Treadwear Indicators:Narrow bands, sometimes
called “wear bars,” that show across the tread of a tire
when only 1/16 inch (1.6 mm) of tread remains. See
When It Is Time for New Tires on page 5-86.
UTQGS (Uniform Tire Quality Grading Standards):A
tire information system that provides consumers with
ratings for a tire’s traction, temperature, and treadwear.
Ratings are determined by tire manufacturers using
government testing procedures. The ratings are molded
into the sidewall of the tire. SeeUniform Tire Quality
Grading on page 5-87.
Vehicle Capacity Weight:The number of designated
seating positions multiplied by 150 lbs (68 kg) plus
the rated cargo load. SeeLoading Your Vehicle
on page 4-29.
Vehicle Maximum Load on the Tire:Load on an
individual tire due to curb weight, accessory weight,
occupant weight, and cargo weight.
Vehicle Placard:A label permanently attached to a
vehicle showing the vehicle’s capacity weight and
the original equipment tire size and recommended
ination pressure. See “Tire and Loading Information
Label” underLoading Your Vehicle on page 4-29.Ination - Tire Pressure
Tires need the correct amount of air pressure to operate
effectively.
Notice:Do not let anyone tell you that
under-ination or over-ination is all right. It is not.
If your tires do not have enough air (under-ination),
you can get the following:
Too much exing
Too much heat
Tire overloading
Premature or irregular wear
Poor handling
Reduced fuel economy
If your tires have too much air (over-ination), you
can get the following:
Unusual wear
Poor handling
Rough ride
Needless damage from road hazards
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A Tire and Loading Information label is attached to the
vehicle’s center pillar, below the driver’s door latch.
This label lists your vehicle’s original equipment
tires and shows the correct ination pressures for your
tires when they are cold. The recommended cold
tire ination pressure, shown on the label, is the
minimum amount of air pressure needed to support your
vehicle’s maximum load carrying capacity.
For additional information regarding how much weight
your vehicle can carry, and an example of the tire
and loading information label, seeLoading Your Vehicle
on page 4-29. How you load your vehicle affects
vehicle handling and ride comfort, never load your
vehicle with more weight than it was designed to carry.How to Check
Use a good quality pocket-type gage to check tire
pressure. You cannot tell if your tires are properly
inated simply by looking at them. Radial tires may look
properly inated even when they’re under-inated.
Check the tire’s ination pressure when the tires
are cold. Cold means your vehicle has been sitting
for at least three hours or driven no more than
1 mile (1.6 km).
Remove the valve cap from the tire valve stem. Press
the tire gage rmly onto the valve to get a pressure
measurement. If the cold tire ination pressure matches
the recommended pressure on the Tire and Loading
Information label, no further adjustment is necessary. If
the ination pressure is low, add air until you reach
the recommended amount.
If you overll the tire, release air by pushing on the
metal stem in the center of the tire valve. Re-check the
tire pressure with the tire gage.
Be sure to put the valve caps back on the valve
stems. They help prevent leaks by keeping out dirt
and moisture.
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High Speed Operation
{CAUTION:
Driving at high speeds, 100 mph (160 km/h) or
higher, puts an additional strain on tires.
Sustained high-speed driving, causes
excessive heat build up and can cause sudden
tire failure. You could have a crash and you or
others could be killed. Some high-speed rated
tires require ination pressure adjustment for
high speed operation. When speed limits and
road conditions are such, that a vehicle can be
driven at high speeds, make sure the tires are
rated for high speed operation, in excellent
condition and set to the correct cold tire
ination pressure for the vehicle load.If you’ll be driving at high speeds, speeds of 100 mph
(160 km/h) or higher, where it is legal, set the cold
ination pressure to the maximum ination pressure
shown on the tire sidewall, or to 35 psi (244 kPa),
whichever is lower. See the example below. When you
end this high-speed driving, return to the cold ination
pressure shown on the Tire and Loading Information
label. SeeLoading Your Vehicle on page 4-29.
Example:
You’ll nd maximum load and ination pressure molded
on the tire’s sidewall, in small letters near the rim
ange. It will read something like this: Maximum load
690 kg (1521 lbs) 300 kPa (44 psi) Max. Press.
For this example, you would set the ination pressure
for high-speed driving at 35 psi (244 kPa).
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Check Tire Pressure System
The check tire pressure system can alert you to a
large change in the pressure of one tire. The system
will not alert you before you drive that a tire is low or
at. You must begin driving before the system will
work properly.
The CHECK TIRE PRESSURE message will appear on
the Driver Information Center (DIC) or the system
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 compact spare tire is installed.
The tire treadwear is uneven.
Tire chains are being used.
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
Anti-Lock Brake System Warning Light on page 3-42.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 does not replace normal tire
maintenance. SeeTires on page 5-74.
When the CHECK TIRE PRESSURE message appears
on the Driver Information Center (DIC) or 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 at, seeIf a Tire Goes Flat on
page 5-92. Also check the tire pressure in all four tires
as soon as you can. SeeInation - Tire Pressure
on page 5-80.
Any time you adjust a tire’s pressure or have one or
more tires repaired or replaced, you will need to reset
(calibrate) the check tire pressure system. You will
also need to reset the system whenever you rotate
the tires, buy new tires and install or remove the
compact spare.
Do not reset the check tire pressure system without rst
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.
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To reset (calibrate) the system with a Driver Information
Center (DIC):
1. Turn the ignition switch to ON.
2. Using the MODE and SELECT buttons, change the
DIC to display TIRE PRESSURE.
3. Press and hold the RESET button for about
ve seconds.
4. The display should change to read TIRE
PRESSURE RESET. If TIRE PRESSURE
RESET does not appear on the display after about
ve 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:
1. Turn the ignition switch to ON.
2. Press and hold the TIRE PRESS RESET button for
about ve seconds.
3. The TIRE PRESS light on the systems monitor
should begin to ash. If the TIRE PRESS light
does not begin to ash after about ve seconds,
see your dealer for service.
4. Release the TIRE PRESS RESET button and the
system should reset. The TIRE PRESS light will
go 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).
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