wheel size CADILLAC CTS 2005 1.G Owners Manual

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, see
Buying New Tires on page 5-69.
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 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.
Aspect Ratio:The relationship of a tire’s height to
its width.
5-58

Tire Pressure Monitor System
(CTS-V)
The Tire Pressure Monitor (TPM) System uses radio
and sensor technology to check tire pressure levels.
If your vehicle has this feature, sensors are mounted
on each run-at tire and wheel assembly. The TPM
sensors transmit tire pressure readings to a receiver
located in the vehicle once every 60 seconds while the
vehicle is being driven, and once every 60 minutes
if the vehicle is stationary for more than 15 minutes.
Using the Message Center, tire pressure levels can be
viewed by the driver. For additional information about
the message center operation and displays, see
Message Center (CTS-V) on page 3-51.
When a low tire pressure condition is detected, a low
tire warning light, on the instrument panel cluster,
comes on to warn the driver.
When the tire pressure
monitoring system warning
light is lit, one or more
of your tires is signicantly
under-inated.You should stop and check your tires as soon as
possible, and inate them to the proper pressure as
indicated on the vehicle’s tire information placard.
Driving on a signicantly under-inated tire causes
the tire to overheat and can lead to tire failure.
Under-ination also reduces fuel efficiency and tire tread
life, and may affect the vehicle’s handling and stopping
ability. Each tire, should be checked monthly when
cold and set to the recommended ination pressure as
specied in the vehicle placard and owner’s manual.
The Tire and Loading Information label (tire information
placard) is attached, to either, the center pillar near
the driver’s door latch post or on the rear edge of the
driver’s side rear passenger door. The label shows
the size of your vehicle’s original tires and the correct
ination pressure for your vehicle’s tires when they
are cold. SeeInation - Tire Pressure on page 5-62and
Loading Your Vehicle on page 4-33for additional
information.
Your vehicle’s TPM system can alert you about a low
tire pressure condition but it does not replace normal
tire maintenance. SeeTire Inspection and Rotation
on page 5-67andTires on page 5-54.
Notice:Do not use a tire sealant if your vehicle is
equipped with Tire Pressure Monitors. The liquid
sealant can damage the tire pressure monitor
sensors.
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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.
{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 (CTS) on page 5-85.
{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.)
5-70

Tire Chains
{CAUTION:
Do not use tire chains. There is 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, re-adjust or remove
the device if it is contacting your vehicle,
and do not spin your wheels. If you do nd
traction devices that will t, install them on
the rear tires.
If a Tire Goes Flat
It is unusual for a tire to “blowout” while you’re driving,
especially if you maintain your tires properly. See
Tires on page 5-54. If air goes out of a tire, it’s much
more likely to leak out slowly. But if you should
ever have a “blowout”, here are a few tips about what
to expect and what to do:
If a front tire fails, the at tire will create a drag that
pulls the vehicle toward that side. Take your foot off the
accelerator pedal and grip the steering wheel rmly.
Steer to maintain lane position, and then gently brake
to a stop well out of the traffic lane.
A rear blowout, particularly on a curve, acts much like
a skid and may require the same correction you’d use
in a skid. In any rear blowout, remove your foot from
the accelerator pedal. Get the vehicle under control
by steering the way you want the vehicle to go. It may
be very bumpy and noisy, but you can still steer.
Gently brake to a stop — well off the road if possible.
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13. Tighten the wheel nuts
rmly in a crisscross
sequence as shown.
Notice:Wheel covers will not t on your compact
spare. If you try to put a wheel cover on the compact
spare, you could damage the cover or the spare.
Do not try to put a wheel cover on your compact spare
tire. It will note t. Store the wheel cover in the trunk
until you have the at tire repaired or replaced.Storing a Flat or Spare Tire and
Tools (CTS)
{CAUTION:
Storing a jack, a tire, or other equipment in the
passenger compartment of the vehicle could
cause injury. In a sudden stop or collision,
loose equipment could strike someone. Store
all these in the proper place.
After you’ve put the compact spare tire on your vehicle,
you will need to store the at tire in your trunk.
Remove the foam support so that the at tire will
t in the storage area. Place the at tire with the
appearance-side face down and store the jack container
in the center of the tire. See the diagram for more
information.
The compact spare is for temporary use only. Replace
the compact spare tire with a full-size tire as soon
as you can.
5-84

Use the following diagram as a guide for storing the
compact spare tire in the trunk:
A. Compact Spare Tire
Cover Wing Nut
B. Compact Spare
Tire Cover
C. Plastic Wing Nut
D. Retainer
E. Jack Container
with Wheel Wrench
and JackF. Flat Road Tire
G. Compact Spare Tire
H. Foam Insert
I. Bolt
J. Wheel Wrench
K. Jack
L. Jack ContainerCompact Spare Tire (CTS)
Although the compact spare tire was fully inated
when the vehicle was new, it can lose air after a time.
Check the ination pressure regularly. It should be
60 psi (420 kPa).
After installing the compact spare on the vehicle, stop
as soon as possible and make sure the spare tire
is correctly inated. The compact spare is made to
perform well at speeds up to 65 mph (105 km/h)
for distances up to 3,000 miles (5 000 km), so you can
nish your trip and have the full-size tire repaired or
replaced at your convenience. Of course, it is best
to replace the spare with a full-size tire as soon as
possible. The spare tire will last longer and be in good
shape in case it is needed again.
Notice:When the compact spare is installed, do
not take your vehicle through an automatic car
wash with guide rails. The compact spare can get
caught on the rails. That can damage the tire
and wheel, and maybe other parts of your vehicle.
Do not use the compact spare on other vehicles.
And do not mix the compact spare tire or wheel with
other wheels or tires. They will not t. Keep the
spare tire and its wheel together.
Notice:Tire chains will not t your compact spare.
Using them can damage your vehicle and can
damage the chains too. Do not use tire chains on
your compact spare.
5-85