2004 CADILLAC CTS 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.Remember: Any traction control system helps avoid only
the acceleration skid. If your traction control 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.
Remember: Any anti-lock brake system (ABS) helps
avoid only the braking skid.
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Notice:If your vehicle has P245/45R18 size
tires, they are classied as low-prole tires.
Low-prole tires are more susceptible to damage
from road hazards or curb impact than standard
prole tires. Tire and or wheel assembly damage can
occur when coming into contact with road hazards
like, potholes or sharp edged objects or when
sliding into a curb. Your GM warranty does not
cover this type of damage. Keep tires set to
the correct ination pressure and, when possible
avoid contact with curbs, potholes and other
road hazards.Winter Tires
If you expect to drive on snow or ice covered roads
often, you may want to get winter tires for your vehicle.
All season tires provide good overall performance on
most surfaces but they may not offer the traction
you would like or the same level of performance as
winter tires on snow or ice covered roads.
See your dealer for details regarding winter tire
availability and proper tire selection. Also, seeBuying
New Tires on page 5-74
If you choose to use snow tires:
Use tires of the same brand and tread type on
all four wheel positions.
Use only radial ply tires of the same size,
load range, and speed rating as the original
equipment tires.
Winter tires with the same speed rating as your original
equipment tires may not be available for H, V, W
and ZR speed rated tires. If you choose snow tires with
a lower speed rating, never exceed the tire’s maximum
speed capability.
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Tire Sidewall Labeling
Useful information about a tire is molded into its
sidewall. The examples below show a typical passenger
car tire and a compact spare tire sidewall.
(A) Tire Size Code: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.
(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 5-75.
(G) Maximum Cold Ination Load Limit:Maximum
load that can be carried and the maximum pressure
needed to support that load. For information on
recommended tire pressure seeInation - Tire Pressure
on page 5-67andLoading Your Vehicle on page 4-34. Passenger Car 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 spare
tire, seeCompact Spare Tire on page 5-91andIf 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 5-91andLoading Your Vehicle on page 4-34.
(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
seeInation - 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. Compact Spare Tire Example
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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.(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 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”.
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A Tire and Loading Information label is attached to the
vehicle’s center pillar, below the driver’s door latch
or on the rear edge of the driver’s side, rear passenger
door. This label lists your vehicle’s original equipment
tires and their recommended cold tire ination pressures.
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 4-34. How you load your vehicle affects
vehicle handling and ride comfort, never load your
vehicle with more weight than it was designed to carry.
When to Check
Check your tires once a month or more. Do not forget to
check the compact spare tire. If your vehicle has one,
it should be at 60 psi (420 kPa). For additional
information regarding the compact spare tire,
seeCompact Spare Tire on page 5-91.
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. 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. 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.
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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 4-34.
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, 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 “MS” (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.
Winter tires with the same speed rating as your original
equipment tires may not be available for H, V, W,
and ZR speed rated tires. If you choose snow tires with
a lower speed rating, never exceed the tire’s maximum
speed capability.
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.
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{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.
It’s all right to drive with your compact spare
temporarily, it was developed for use on your
vehicle. SeeCompact Spare Tire on page 5-91.
{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.
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.
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