2004 CADILLAC XLR tire type

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
ªoverdrivingº 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.
Remember: Any traction control system helps avoid only
the acceleration skid. If your TCS 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 Ð such as enough water, ice or packed snow
on the road to make a ªmirrored surfaceº Ð and slow
down when you have any doubt.
Remember: Any anti-lock brake system (ABS) helps
avoid only the braking skid.
4-17

Rocking Your Vehicle To Get It Out
First, turn your steering wheel left and right. That will
clear the area around your front wheels. Turn your
traction control system off; see
Traction Control System
(TCS) on page 4-9. Then shift back and forth between
REVERSE (R) and a forward gear, spinning the wheels
as little as possible. Release the accelerator pedal
while you shift, and press lightly on the accelerator pedal
when the transmission is in gear. By slowly spinning
your wheels in the forward and reverse directions, you
will cause a rocking motion that may free your
vehicle. If that does not get you out after a few tries,
you may need to be towed out. If you do need to
be towed out, see
Towing Your Vehicle on page 4-32.
Towing
Towing Your Vehicle
Consult your dealer or a professional towing service if
you need to have your disabled vehicle towed. See
Roadside Service on page 7-5.
Recreational Vehicle Towing
Recreational vehicle towing means towing your vehicle
behind another vehicle Ð such as behind a motorhome.
The two most common types of recreational vehicle
towing are known as ªdinghy towingº (towing your
vehicle with all four wheels on the ground) and ªdolly
towingº (towing your vehicle with two wheels on
the ground and two wheels up on a device known
as a ªdollyº).
Your vehicle was not designed to be towed with any of
its wheels on the ground. If your vehicle must be
towed, see ªTowing Your Vehicleº earlier in this section.
Loading Your Vehicle
It is very important to know how much weight your
vehicle can carry. This weight is called the vehicle
capacity weight and includes the weight of all occupants,
cargo and all nonfactory-installed options. Two labels
on your vehicle show how much weight it may properly
carry, the Tire and Loading Information label and the
Certi®cation label.
4-32

A. Tire Size
B. Tire Performance Criteria Speci®cation (TPC Spec)
C. Department of Transportation (DOT)
D. Tire Identi®cation Number (TIN)
E. Tire Ply Material
F. Uniform Tire Quality Grading (UTQG)
G. Maximum Cold In¯ation Load Limit
(A) Tire Size:The tire size code is a combination of
letters and numbers used to de®ne a particular
tire's width, height, aspect ratio, construction type and
service description. See the ªTire Size º illustration later
in this section for more detail.
(B) Tire Performance Criteria Speci®cation (TPC
Spec):Original equipment tires designed to GM's
speci®c tire performance criteria have a TPC
speci®cation code molded onto the sidewall. GM's TPC
speci®cations 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.
5-51

(D) Tire Identi®cation Number (TIN):The letters and
numbers following DOT code are the Tire Identi®cation
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 5-64.
(G) Maximum Cold In¯ation Load Limit:Maximum
load that can be carried and the maximum pressure
needed to support that load. For more information on
recommended tire pressure see
In¯ation - Tire Pressure
on page 5-57andLoading Your Vehicle on page 4-32.
Tire Size Codes
The following illustration shows an example of a typical
passenger car tire size.
A. P-Metric Tire
B. Tire Width
C. Aspect RatioD. Construction Code
E. Rim Diameter
F. Service Description
5-52

(A) P-Metric Tire:The United States version of a
metric tire sizing system. The letter ªPº 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 ª70,º as shown in item ªCº 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
ªRº means radial ply construction; the letter ªDº means
diagonal or bias ply construction; and the letter ªBº
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
certi®ed to carry. The load index can range from 1 to
279. The speed rating is the maximum speed a tire
is certi®ed to carry a load. Speed ratings range
from ªAº to ªZº.Tire Terminology and De®nitions
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.
Cold In¯ation Pressure:The amount of air pressure in
a tire, measured in pounds per square inch (psi)
before a tire has built up heat from driving. See
In¯ation - Tire Pressure on page 5-57.
5-53

When to Check
Check your tires once a month or more.
How to Check
Use a good quality pocket-type gage to check tire
pressure. You can't tell if your tires are properly in¯ated
simply by looking at them. Radial tires may look
properly in¯ated even when they're underin¯ated. Check
tire in¯ation pressure when the tire is 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 in¯ation pressure matches
the recommended pressure on the Tire and Loading
Information label, no further adjustment is necessary.
If the in¯ation pressure is low, add air until you reach the
recommended amount.
If you over®ll 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.
Tire Pressure Monitor (TPM)
Your vehicle has a Tire Pressure Monitor (TPM) that
sends tire pressure information to the Driver Information
Center (DIC). Using the DIC control buttons, the
driver is able to check tire pressure levels in all four
road tires. See
Tire Pressure Monitor System on
page 5-58andDIC Controls and Displays on page 3-55for additional information.
Tire Pressure Monitor System
The Tire Pressure Monitor (TPM) System on your
vehicle, uses radio and sensor technology to check tire
pressure levels. Sensors, mounted on each tire and
wheel assembly transmit tire pressure readings to
a receiver located in the vehicle. The TPM sensors
transmit tire pressure readings once every 60 seconds
while the vehicle is being driven and once every
60 minutes when the vehicle is stationary for more than
15 minutes. Using the Driver Information Center
(DIC), tire pressure levels can be viewed by the driver.
The TPM system also uses the DIC to warn the
driver when air pressure, in one or more tires, falls
below 25 psi (172 kPa) or is above 38 psi (262 kPa).
For additional information and details about the
DIC operation and displays see
DIC Controls and
Displays on page 3-55andDIC Warnings and Messages
on page 3-57.
5-58

Buying New Tires
To ®nd out what kind and size of tires you need, look at
the Tire and Loading Information label. For information
about this label and where to ®nd it, see
Loading
Your Vehicle on page 4-32.
The tires installed on your vehicle when it was new had
a Tire Performance Criteria Speci®cation (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, tire pressure monitoring system performance
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).
Whenever you 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.
If you replace your vehicle's tires with those not having a
TPC Spec number, the tire pressure monitoring
system may give an inaccurate low-pressure warning.
Non-TPC Spec tires may give a low-pressure warning
that is higher or lower than the proper warning level you
would get with TPC Spec numbered 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.
{CAUTION:
If you use bias-ply tires on your vehicle, the
wheel rim ¯anges 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.
5-63

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.
Treadwear
The treadwear grade is a comparative rating based on
the wear rate of the tire when tested under controlled
conditions on a speci®ed government test course.
For example, a tire graded 150 would wear one and
a half (1.5) 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 signi®cantly 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 speci®ed 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.
5-64