tire size CADILLAC STS 2008 1.G Owners Manual

Tire and Loading Information Label
A vehicle specic Tire and Loading Information
label is attached to the vehicle’s center pillar
(B-pillar). With the driver’s door open, you will nd
the label attached below the door lock post (striker).
The Tire and Loading Information label shows the
number of occupant seating positions (A), and the
maximum vehicle capacity weight (B) in kilograms
and pounds.The Tire and Loading Information label also shows
the tire size of the original equipment tires (C) and
the recommended cold tire ination pressures (D).
For more information on tires and ination seeTires
on page 5-57andInflation - Tire Pressure on
page 5-66.
There is also important loading information on the
Certication label. It tells you the Gross Vehicle
Weight Rating (GVWR) and the Gross Axle Weight
Rating (GAWR) for the front and rear axle; see
“Certication Label” later in this section.
Steps for Determining Correct Load
Limit
1.Locate the statement “The combined weight of
occupants and cargo should never exceed
XXX kg or XXX lbs” on your vehicle’s placard.
2.Determine the combined weight of the driver
and passengers that will be riding in your
vehicle.
3.Subtract the combined weight of the driver
and passengers from XXX kg or XXX lbs.
Example Label
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Tire Pressure Monitor System.........................5-68
Tire Pressure Monitor Operation.....................5-70
Tire Inspection and Rotation...........................5-73
When It Is Time for New Tires.......................5-75
Buying New Tires.........................................5-76
Different Size Tires and Wheels......................5-78
Uniform Tire Quality Grading..........................5-79
Wheel Alignment and Tire Balance..................5-80
Wheel Replacement......................................5-80
Tire Chains..................................................5-82
Lifting Your Vehicle (STS-V)...........................5-83
If a Tire Goes Flat........................................5-86
Tire Sealant and Compressor Kit....................5-87
Changing a Flat Tire.....................................5-96
Removing the Spare Tire and Tools................5-98
Removing the Flat Tire and Installing
the Spare Tire..........................................5-99
Storing a Flat or Spare Tire and Tools...........5-104
Compact Spare Tire....................................5-106
Appearance Care..........................................5-107
Interior Cleaning.........................................5-107
Fabric/Carpet..............................................5-108
Leather......................................................5-109
Instrument Panel, Vinyl, and Other
Plastic Surfaces.......................................5-109
Wood Panels..............................................5-110Speaker Covers..........................................5-110
Care of Safety Belts....................................5-110
Weatherstrips.............................................5-110
Washing Your Vehicle..................................5-110
Cleaning Exterior Lamps/Lenses....................5-111
Finish Care................................................5-111
Windshield and Wiper Blades.......................5-112
Aluminum or Chrome-Plated Wheels and Trim . . .5-112
Tires.........................................................5-113
Sheet Metal Damage...................................5-113
Finish Damage...........................................5-114
Underbody Maintenance...............................5-114
Chemical Paint Spotting...............................5-114
Vehicle Care/Appearance Materials................5-115
Vehicle Identication.....................................5-116
Vehicle Identication Number (VIN)................5-116
Service Parts Identication Label...................5-116
Electrical System..........................................5-116
Add-On Electrical Equipment.........................5-116
Headlamp Wiring........................................5-117
Windshield Wiper Fuses...............................5-117
Power Windows and Other Power Options......5-117
Fuses and Circuit Breakers..........................5-117
Underhood Fuse Block................................5-118
Rear Underseat Fuse Block..........................5-121
Capacities and Specications........................5-128
Section 5 Service and Appearance Care
5-2

Low-Prole Performance Tires
If your vehicle has 255/45ZR18, P255/45R18 or
P275/40R19 size tires, they are classied as
low-prole performance tires. These tires are
designed for very responsive driving on wet or dry
pavement. You may also notice more road noise
with low-prole performance tires and that they tend
to wear faster. These performance tires are not
rated as all-season tires. Winter tires are
recommended for snow or ice covered roads.
Notice:If your vehicle has low-prole tires,
they 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
vehicle 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.
Winter tires, in general, are designed for increased
traction on snow and ice covered roads. With winter
tires, there may be decreased dry road traction,
increased road noise, and shorter tread life. After
switching to winter tires, be alert for changes in vehicle
handling and braking.
See your dealer/retailer for details regarding winter tire
availability and proper tire selection. Also, seeBuying
New Tires on page 5-76.
If you choose to use winter 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, Y,
and ZR speed rated tires. If you choose winter tires with
a lower speed rating, never exceed the tire’s maximum
speed capability.
5-58

Tire Sidewall Labeling
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. Passenger (P-Metric) Tire Example
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(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 seeInflation - Tire Pressure on
page 5-66.
(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.
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.
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(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.
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.
5-62

Vehicle Placard:A label permanently attached to
a vehicle showing the vehicle’s capacity weight
and the original equipment tire size and
recommended ination pressure. See “Tire and
Loading Information Label” underLoading
Your Vehicle on page 4-26.
Run-Flat Tires (STS-V)
If your vehicle has run-at tires, there is no spare tire
and no tire changing equipment. Your vehicle also has a
Tire Pressure Monitor System (TPMS) which will alert
you if there is a loss of tire pressure in any of the tires.
SeeTire Pressure Monitor System on page 5-68.
{CAUTION:
When the low tire warning light is displayed on
the instrument panel cluster, your vehicle’s
handling capabilities will be reduced during
severe maneuvers. If you drive too fast, you
could lose control of your vehicle. You or
others could be injured. Do not drive over
55 mph (90 km/h) when the low tire warning
light is displayed. Drive cautiously and check
your tire pressures as soon as you can.If a tire goes at, you will not need to stop on the side
of the road to change the tire. You can just keep on
driving. The vehicle’s run-at tires can operate effectively
with no air pressure for up to 50 miles (80 km) at
speeds up to 55 mph (90 km/h). The shorter the
distance you drive and the slower the speed, the greater
the chance that the tire will not have to be replaced.
When a tire is lled with air, it provides a cushion
between the road and the wheel. Because you will not
have this cushion when driving on a deated run-at
tire, try to avoid potholes that could damage your wheel
and require replacement of it.
Some road hazards can damage a tire beyond repair.
This damage could occur even before you have
driven on the tire in a deated condition. When a tire
has been damaged, or if you have driven any distance
on a deated run-at tire, check with an authorized
run-at tire service center, as soon as possible,
to determine whether the tire can be repaired or should
be replaced. To maintain your vehicle’s run-at
feature, all replacement tires must be self-supporting
tires. To locate the nearest GM or authorized run-at
servicing facility, call Roadside Service. SeeRoadside
Service on page 7-6for details.
5-65

High-Speed Operation
{CAUTION:
Driving at high speeds, 100 mph (160 km/h) or
higher, puts an additional strain on tires.
Sustained high-speed driving causes
excessive heat build up and can cause sudden
tire failure. You could have a crash and you or
others could be killed. Some high-speed rated
tires require ination pressure adjustment for
high speed operation. When speed limits and
road conditions are such that a vehicle can be
driven at high speeds, make sure the tires are
rated for high speed operation, in excellent
condition, and set to the correct cold tire
ination pressure for the vehicle load.
If you will be driving at high speeds, speeds of
100 mph (160 km/h) or higher, where it is legal, set the
cold ination pressure to the maximum ination
pressure shown on the tire sidewall, or 38 psi (265 kPa),
whichever is lower. See the example following. When
you end this high-speed driving, return the tires tothe cold ination pressure shown on the Tire and
Loading Information label. SeeLoading Your Vehicle on
page 4-26.
Example:
You will nd the maximum load and ination pressure
molded on the tire’s sidewall, in small letters, near
the rim ange. It will read something like this: Maximum
load 690 kg (1521 lbs) 300 kPa (44 psi) Max. Press.
For this example, you would set the ination pressure for
high-speed driving at 38 psi (265 kPa).
Tire Pressure Monitor System
The Tire Pressure Monitor System (TPMS) uses radio
and sensor technology to check tire pressure levels.
The TPMS sensors monitor the air pressure in
your vehicle’s tires and transmit tire pressure readings
to a receiver located in the vehicle.
Each tire, including the spare (if provided), should be
checked monthly when cold and inated to the ination
pressure recommended by the vehicle manufacturer
on the vehicle placard or tire ination pressure label.
(If your vehicle has tires of a different size than the size
indicated on the vehicle placard or tire ination
pressure label, you should determine the proper tire
ination pressure for those tires.)
5-68

The low tire pressure warning light may come on in cool
weather when the vehicle is rst started, and then
turn off as you start to drive. This could be an early
indicator that the air pressure in the tire(s) are getting
low and need to be inated to the proper pressure.
A Tire and Loading Information label, attached to your
vehicle, shows the size of your vehicle’s original
equipment tires and the correct ination pressure for your
vehicle’s tires when they are cold. SeeLoading Your
Vehicle on page 4-26for an example of the Tire and
Loading Information label and its location on your vehicle.
Also seeInflation - Tire Pressure on page 5-66.
Your vehicle’s TPMS can warn you about a low tire
pressure condition but it does not replace normal
tire maintenance. SeeTire Inspection and Rotation on
page 5-73andTires on page 5-57.
Your vehicle, when new, may have included a
factory-installed Tire Inator Kit. This kit uses a GM
approved liquid tire sealant. SeeTire Sealant and
Compressor Kit on page 5-87.
Notice:Using non-approved tire sealants could
damage the Tire Pressure Monitor System (TPMS)
sensors. TPMS sensor damage caused by using
an incorrect tire sealant is not covered by the
vehicle warranty. Always use the GM approved tire
sealant available through your dealer/retailer.TPMS Malfunction Light and Message
The TPMS will not function properly if one or more of the
TPMS sensors are missing or inoperable. When the
system detects a malfunction, the low tire warning light
ashes for about one minute and then stays on for
the remainder of the ignition cycle. A DIC warning
message is also displayed. The low tire warning light
and DIC warning message come on at each ignition
cycle until the problem is corrected. Some of the
conditions that can cause the malfunction light and
DIC message to come on are:
One of the road tires has been replaced with the
spare tire. The spare tire does not have a TPMS
sensor. The DIC message should go off once
you re-install the road tire containing the TPMS
sensor.
The TPMS sensor matching process was started
but not completed or not completed successfully
after rotating the vehicle’s tires. The DIC message
and TPMS malfunction light should go off once
the TPMS sensor matching process is performed
successfully. See “TPMS Sensor Matching Process”
later in this section.
5-71

The TPM matching process is outlined below:
1. Set the parking brake.
2. Press the push-button ignition switch to Acc.
3. Using the keyless access transmitter, lock and
unlock the vehicle’s doors.
4. Press the lock and unlock buttons, at the same
time, on the keyless access transmitter. A single
horn chirp will sound, indicating that the TPMS
is ready, and the sensor matching process
can begin.
5. Start with the driver side front tire.
6. Remove the valve cap from the valve stem.
Activate the TPMS sensor by increasing or
decreasing the tire’s air pressure for ve seconds,
or until a horn chirp sounds. The horn chirp,
which may take up to 30 seconds to sound,
conrms that the sensor identication code has
been matched to this tire position.
7. Proceed to the passenger side front tire, and repeat
the procedure in Step 6.
8. Proceed to the passenger side rear tire, and repeat
the procedure in Step 6.
9. Proceed to the driver side rear tire, and repeat the
procedure in Step 6.10. After hearing the conrming single horn chirp for the
driver side rear tire, a double horn chirp will sound to
signal the tire matching mode is no longer active.
Press the push-button ignition switch to Acc.
11. Set all four tires to the recommended air pressure
level as indicated on the tire and loading information
label.
12. Put the valve caps back on the valve stems.
Tire Inspection and Rotation
We recommend that you regularly inspect your
vehicle’s tires, including the spare tire, for signs of
wear or damage. SeeWhen It Is Time for New
Tires on page 5-75for more information.
Tire rotation is not recommended if your vehicle
has the following performance tire combinations:
P235/50R17 size tires on the front wheels
and P255/45R17 size tires on the rear wheels.
P235/50ZR18 size tires on the front wheels
and P255/45ZR18 size tires on the rear
wheels.
P255/45R18 size tires on the front wheels and
P275/40R19 size tires on the rear wheels.
5-73