2005 PONTIAC GRAND PRIX tire type

Display Units:This menu allows selection of
measurements to be displayed in English or metric
units. The messages on the HUD, if equipped, and the
instrument panel cluster will also appear with the
type of measurement selected.
To set the measurement when Display Units is shown,
use the following procedure:
1. Press the set/reset button to select ENGLISH or
METRIC.
2. Press the options button again to advance to the
next screen.
DAYTIME DISPLAY ENHANCEMENTS:This menu
allows selection of the color of the display message.
When ON is selected for the daytime enhancement,
the messages will appear black on a red screen. This
combination makes it easier to see the DIC messages
during the daytime. When OFF is selected, or when
the headlamps are on, the messages will appear red
on a black background.
To set the daytime display enhancements, use the
following procedure:
1. Press the set/reset button to select OFF or ON.
2. Press the options button again to advance to
the next screen.ENGINE OIL MONITOR SYSTEM:This menu allows
the engine oil monitor system to be reset. See
Engine Oil Life System on page 5-18.
To reset the engine oil monitor system, use the following
procedure:
1. Press the set/reset button after an oil change to
reset the engine oil monitor system. The
conrmation, ENGINE OIL MONITOR SYSTEM
HAS BEEN RESET, will appear on the screen and
a chime will sound.
2. Press the options button again to advance to the
next screen.
Tire Ination Monitor System:If the vehicle has ABS,
this menu sets the tire ination monitor system. See “Tire
Ination Monitor System” underInation - Tire Pressure
on page 5-64for more information.
To set or reset the tire ination monitor system, use the
following procedure:
1. Press the set/reset button to reset the tire ination
monitor system. The message, TIRE INFLATION
HAS BEEN SET, will appear on the screen if
the Check Tire Pressure message, indicating
an irregularity in the pressure of one of the
tires, had previously appeared on the DIC.
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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 do not have the Enhanced Traction System or the
Traction Control System, 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.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.
While driving on a surface with reduced traction, try
your best to avoid sudden steering, acceleration,
or braking, including engine braking by shifting to a
lower gear. Any sudden changes could cause the tires
to slide. You may not realize the surface is slippery
until your vehicle is skidding. Learn to recognize warning
clues — such as enough water, ice, or packed snow
on the road to make a mirrored surface — and
slow down when you have any doubt.
If you have the anti-lock braking system, remember: It
helps avoid only the braking skid. If you do not have
anti-lock, then in a braking skid, where the wheels are
no longer rolling, release enough pressure on the brakes
to get the wheels rolling again. This restores steering
control. Push the brake pedal down steadily when
you have to stop suddenly. As long as the wheels are
rolling, you will have steering control.
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When using a weight-carrying hitch or a
weight-distributing hitch, the trailer tongue (A) should
weigh 10 to 15 percent of the total loaded trailer
weight (B).
After the trailer is loaded, weigh the trailer and then the
tongue, separately, to see if the weights are proper.
The correct weight could be achieved simply by moving
some items around in the trailer.
Total Weight on Your Vehicle’s Tires
Be sure the vehicle’s tires are inated to the upper limit
for cold tires. These numbers can be found on the
Tire Loading Information label, that is on the inside of
the trunk lid. SeeLoading Your Vehicle on page 4-33.
Be sure not to go over the GVW limit for the vehicle, or
the GAWR, including the weight of the trailer tongue.
If a weight distribution hitch is used, make sure not to go
over the rear axle limit before applying the weight
distribution spring bars.
Hitches
It is important to have the correct hitch equipment.
Crosswinds, large trucks going by, and rough roads are
a few reasons why the correct hitch is needed. Here
are some rules to follow:
The rear bumper on the 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.
If any holes need to be made in the body of the
vehicle to install a trailer hitch, then be sure to seal
the holes later when the hitch is removed. If the holes
are not sealed, deadly carbon monoxide (CO) from
the exhaust can get into the vehicle. SeeEngine
Exhaust on page 2-33. Dirt and water can, too.
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Tire Sidewall Labelling
Useful information about a tire is molded into its
sidewall. The examples below show a typical passenger
vehicle tire and a compact spare tire sidewall.
(A) Tire Size:The tire size 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) TPC Spec (Tire Performance Criteria
Specication):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) DOT (Department of Transportation):The
Department of Transportation (DOT) code indicates that
the tire is in compliance with the U.S. Department of
Transportation Motor Vehicle Safety Standards.
(D) Tire Identication Number (TIN):The letters and
numbers following DOT (Department of Transportation)
code is 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 5-69.
(G) Maximum Cold Ination Load Limit:Maximum
load that can be carried and the maximum pressure
needed to support that load. Passenger (P-Metric) Tire Example
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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. If your vehicle has a compact
spare tire, seeCompact Spare Tire on page 5-93
andIf a Tire Goes Flat on page 5-73.
(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 letters
and numbers following the DOT (Department of
Transportation) code is 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.
(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 5-64.
(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) TPC Spec (Tire Performance Criteria
Specication):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. Compact Spare Tire Example
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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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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 are 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.
Tire Pressure Monitor System
The vehicle has the tire ination monitor system, that
can alert the driver to a large change in the pressure of
one tire. It 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 5-58.
The system “learns” the pressure at each tire throughout
the operating speed range of the vehicle. The system
normally takes between 45 and 90 minutes of driving to
learn the tire pressures. This time may be longer
depending on 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 reset.
This symbol, along with the
CHECK TIRE PRESSURE
warning message will
appear in the Driver
Information Center (DIC) if
the pressure in one tire
becomes 12 psi (83 kPa)
lower than the other
three tires.
SeeDIC Warnings and Messages on page 3-69for
more information.
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When It Is 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 nd out what kind and size of tires your vehicle
needs, look at the tire and loading information label.
For more information about this label and its location on
your vehicle, seeLoading Your Vehicle on page 4-33.
The tires installed on your vehicle when it was new had
a Tire Performance Criteria Specication (TPC Spec)
number on each tire’s sidewall. When you get new
tires, GM recommends that you get tires 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, load range, 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 “MS” (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.
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