2004 PONTIAC BONNEVILLE tire type

Loss of Control
Let us review what driving experts say about what
happens when the three control systems (brakes,
steering and acceleration) do not have enough friction
where the tires meet the road to do what the driver
has asked.
In any emergency, do not give up. Keep trying to steer
and constantly seek an escape route or area of less
danger.
Skidding
In a skid, a driver can lose control of the vehicle.
Defensive drivers avoid most skids by taking reasonable
care suited to existing conditions, and by not “overdriving”
those conditions. But skids are always possible.
The three types of skids correspond to your vehicle’s
three control systems. In the braking skid, your wheels
are not rolling. In the steering or cornering skid, too much
speed or steering in a curve causes tires to slip and lose
cornering force. And in the acceleration skid, too much
throttle causes the driving wheels to spin.A cornering skid is best handled by easing your foot off
the accelerator pedal.
If you have the traction control system, remember: It
helps avoid only the acceleration skid. If you do not have
traction control, or if the system is off, then an
acceleration skid is also best handled by easing your
foot off the accelerator pedal.
If your vehicle starts to slide, ease your foot off the
accelerator pedal and quickly steer the way you want
the vehicle to go. If you start steering quickly enough,
your vehicle may straighten out. Always be ready
for a second skid if it occurs.
If you have Stabilitrak®, you may see the STABILITY
SYSTEM ACTIVE message on the Driver Information
Center. See “Stability System Active Message”
underDIC Warnings and Messages on page 3-61.
Of course, traction is reduced when water, snow, ice,
gravel or other material is on the road. For safety,
you will want to slow down and adjust your driving to
these conditions. It is important to slow down on slippery
surfaces because stopping distance will be longer and
vehicle control more limited.
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Total Weight on Your Vehicle’s Tires
Be sure your vehicle’s tires are inated to the upper limit
for cold tires. You will nd these numbers on the
Tire-Loading Information label. SeeLoading Your
Vehicle on page 4-33. Then be sure you do not go over
the GVW limit for your vehicle, including the weight
of the trailer tongue.
Hitches
It is important to have the correct hitch equipment.
Crosswinds, large trucks going by and rough roads are
a few reasons why you will need the right hitch. Here
are some rules to follow:
The rear bumper on your vehicle is not intended for
hitches. Do not attach rental hitches or other
bumper-type hitches to it. Use only a frame-mounted
hitch that does not attach to the bumper.
Will you have to make any holes in the body of your
vehicle when you install a trailer hitch? If you do, then
be sure to seal the holes later when you remove the
hitch. If you do not seal them, deadly carbon
monoxide (CO) from your exhaust can get into your
vehicle. SeeEngine Exhaust on page 2-37. Dirt and
water can also enter the vehicle.
Safety Chains
You should always attach chains between your vehicle
and your trailer. Cross the safety chains under the tongue
of the trailer so that the tongue will not drop to the road if
it becomes separated from the hitch. Instructions about
safety chains may be provided by the hitch manufacturer
or by the trailer manufacturer. Follow the manufacturer’s
recommendation for attaching safety chains and do not
attach them to the bumper. Always leave just enough
slack so you can turn with your rig. And, never allow
safety chains to drag on the ground.
Trailer Brakes
Does your trailer have its own brakes? Be sure to read
and follow the instructions for the trailer brakes so you will
be able to install, adjust and maintain them properly.
Because you have anti-lock brakes, do not try to tap into
your vehicles brake system. If you do, both brake
systems will not work well, or at all.
Trailer Wiring Harness
All of the electrical circuits required for your trailer
lighting system can be accessed at the driver’s side rear
lamp connector. This connector is located under the
carpet in the rear corner of your trunk compartment.
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(A) Tire Size:The tire size code is a combination of
letters and numbers used to dene a particular
tire’s width, height, aspect ratio, construction type and
service description. See the “Tire Size” illustration
later in this section for more detail.
(B) Tire Performance Criteria Specication (TPC
Spec):Original equipment tires designed to GM’s
specic tire performance criteria have a TPC specication
code molded onto the sidewall. GM’s TPC specications
meet or exceed all federal safety guidelines.
(C) Department of Transportation (DOT):The
Department of Transportation (DOT) code indicates that
the tire is in compliance with the U.S. Department of
Transportation Motor Vehicle Safety Standards.
Passenger Car Tire Example
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(D) Tire Identication Number (TIN):The letters and
numbers following DOT code are the Tire Identication
Number (TIN). The TIN shows the manufacturer and
plant code, tire size, and date the tire was manufactured.
The TIN is molded onto both sides of the tire, although
only one side may have the date of manufacture.
(E) Tire Ply Material:The type of cord and number of
plies in the sidewall and under the tread.(F) Uniform Tire Quality Grading (UTQG):Tire
manufacturers are required to grade tires based on three
performance factors: treadwear, traction and
temperature resistance. For more information see
Uniform Tire Quality Grading on page 5-74.
(G) Maximum Cold Ination Load Limit:Maximum
load that can be carried and the maximum pressure
needed to support that load. For more information on
recommended tire pressure seeInation - Tire Pressure
on page 5-67andLoading Your Vehicle on page 4-33.
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(A) Temporary Use Only:The compact spare tire or
temporary use tire has a tread life of approximately
3,000 miles (5 000 km) and should not be driven
at speeds over 65 mph (105 km/h). The compact spare
tire is for emergency use when a regular road tire
has lost air and gone at. SeeCompact Spare Tire on
page 5-90andIf a Tire Goes Flat on page 5-79.
(B) Tire Ply Material:The type of cord and number of
plies in the sidewall and under the tread.
(C) Tire Identication Number (TIN):The Tire
Identication Number (TIN). The TIN shows the
manufacturer and plant code, tire size, and date the tire
was manufactured. The TIN is molded onto both
sides of the tire, although only one side may have the
date of manufacture.
(D) Maximum Cold Ination Load Limit:Maximum
load that can be carried and the maximum pressure
needed to support that load. SeeCompact Spare Tire
on page 5-90andLoading Your Vehicle on page 4-33.
Compact Spare Tire Example
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(E) Tire Ination:The temporary use tire or compact
spare tire should be inated to 60 psi (420 kPa).
For more information on tire pressure and ination see
Ination - Tire Pressure on page 5-67.
(F) Tire Size:A combination of letters and numbers
dene a tire’s width, height, aspect ratio, construction
type and service description. The letter “T” as the
rst character in the tire size means the tire is for
temporary use only.
(G) Tire Performance Criteria Specication (TPC
Spec):Original equipment tires designed to GM’s
specic tire performance criteria have a TPC specication
code molded onto the sidewall. GM’s TPC specications
meet or exceed all federal safety guidelines.Tire Size
The following illustration shows an example of a typical
passenger car tire size.
(A) 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.
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(C) Aspect Ratio:A two-digit number that indicates the
tire height-to-width measurements. For example, if
the tire size aspect ratio is “70,” as shown in item “C” of
the illustration, it would mean that the tire’s sidewall
is 70% 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 the speed rating of a tire. The load
range represents the load carrying 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.
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.
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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 inated
simply by looking at them. Radial tires may look
properly inated even when they’re underinated.
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. Be sure to put the valve caps
back on the valve stems. They help prevent leaks by
keeping out dirt and moisture.
If you overll the tire, release air by pushing on the
metal stem in the center of the tire valve. Recheck 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.
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 3-44.
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