wheel size CADILLAC XLR 2004 1.G Owners Manual

(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

A low tire warning light also appears on the instrument
panel cluster when a low tire condition exists. The
DIC message, CHECK TIRE PRESSURE and the low
tire pressure warning light will be shown each time
the engine is started and stay on until the low tire
condition is corrected.
When the tire pressure
monitoring system warning
light is lit, one or more
of your tires is signi®cantly
under-in¯ated.
You should stop and check your tires as soon as
possible, and in¯ate them to the proper pressure as
indicated on the vehicle's tire information placard.
Driving on a signi®cantly under-in¯ated tire causes the
tire to overheat and can lead to tire failure.
Under-in¯ation also reduces fuel efficiency and tire tread
life, and may affect the vehicle's handling and stopping
ability. Each tire, including the spare, should be
checked monthly when cold and set to the
recommended in¯ation pressure as speci®ed in the
vehicle placard and owner's manual.The Tire and Loading Information Label (tire information
placard) is either on the rear edge of the driver's door
or the driver's door jamb near the latch. This label shows
the size of your vehicle's original tires and the correct
in¯ation pressure for your vehicle's tires when they
are cold. See
In¯ation - Tire Pressure on page 5-57.
Your vehicle's TPM system can alert you about a low or
high tire pressure condition but it does not replace
normal tire maintenance. See
Tire Inspection and
Rotation on page 5-60
Each TPM sensor has a unique identi®cation code that
is matched to one of the four tire positions on your
vehicle. The tire and wheel assembly positions are, left
front (LF); right front (RF); right rear (RR) and left
rear (LR). Any time you rotate your vehicle's tires or
replace one or more TPM sensors, the identi®cation
codes will need to be matched to the new tire and wheel
position. The TPM matching process is performed in
a speci®c sequence and time limit. A special tool is also
required. See your dealer for service.
The SVC TIRE MONITOR message is displayed when
the TPM system is malfunctioning. For example,
one or more TPM sensors may be inoperable or
missing. See your dealer for service.
5-59

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

Used Replacement Wheels
{CAUTION:
Putting a used wheel on your vehicle is
dangerous. You can't know how it's been used
or how far it's been driven. It could fail
suddenly and cause a crash. If you have to
replace a wheel, use a new GM original
equipment wheel.
Tire Chains
{CAUTION:
Don't use tire chains. There's not enough
clearance. Tire chains used on a vehicle
without the proper amount of clearance can
cause damage to the brakes, suspension or
other vehicle parts. The area damaged by the
tire chains could cause you to lose control of
your vehicle and you or others may be injured
in a crash. Use another type of traction device
only if its manufacturer recommends it for use
on your vehicle and tire size combination and
road conditions. Follow that manufacturer's
instructions. To help avoid damage to your
vehicle, drive slowly, readjust or remove the
device if it's contacting your vehicle, and don't
spin your wheels. If you do ®nd traction
devices that will ®t, install them on the
rear tires.
5-68

T
Tachometer....................................................3-41
TCS Warning Light..........................................3-46
Telescopic Steering Column, Power Tilt Wheel...... 3-5
Testing the Alarm............................................2-18
Theft-Deterrent, Radio.....................................3-71
Theft-Deterrent System....................................2-17
Theft-Deterrent Systems...................................2-17
Tire
Pressure Light.............................................3-48
Tire Sidewall Labeling......................................5-50
Tire Size Codes..............................................5-52
Tire Terminology and De®nitions........................5-53
Tires.............................................................5-50
Buying New Tires........................................5-63
Chains.......................................................5-68
If a Tire Goes Flat.......................................5-73
In¯ation - Tire Pressure................................5-57
Inspection and Rotation................................5-60
Lifting Your Vehicle......................................5-69
Pressure Monitor System..............................5-58
Run-Flat.....................................................5-56
Uniform Tire Quality Grading.........................5-64
Wheel Alignment and Tire Balance.................5-65
Wheel Replacement.....................................5-66
When It Is Time for New Tires......................5-62To Use the Engine Coolant Heater....................2-22
Top Strap......................................................1-27
Torque Lock...................................................2-29
Towing
Recreational Vehicle.....................................4-32
Towing a Trailer..........................................4-37
Your Vehicle...............................................4-32
Traction
Control System (TCS).................................... 4-9
Control System Warning Light.......................3-46
Limited-Slip Rear Axle..................................4-10
Magnetic Ride Control..................................4-10
Stabilitrak
žSystem......................................4-11
Transmission
Fluid, Automatic...........................................5-19
Transmission Operation, Automatic....................2-23
Transmission, Transaxle, Transfer Case Unit
Repair Manual............................................7-11
Transportation Options...................................... 7-7
Trip Computer
Oil Life Indicator..........................................3-70
Trip Odometer................................................3-41
Trunk............................................................2-11
Trunk Lock Release........................................2-12
Turn and Lane-Change Signals.......................... 3-6
Turn Signal/Multifunction Lever........................... 3-5
Twilight Sentinel
ž............................................3-24
12