tire size CADILLAC STS 2006 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 5-56
andInation - Tire Pressure on page 5-64.
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. Label Example
4-33

Buying New Tires.........................................5-72
Different Size Tires and Wheels......................5-74
Uniform Tire Quality Grading..........................5-75
Wheel Alignment and Tire Balance..................5-76
Wheel Replacement......................................5-76
Tire Chains..................................................5-78
Lifting Your Vehicle (STS-V )..........................5-79
If a Tire Goes Flat........................................5-81
Changing a Flat Tire (STS Only).....................5-83
Removing the Spare Tire and Tools
(STS Only)...............................................5-85
Removing the Flat Tire and Installing
the Spare Tire (STS Only)..........................5-86
Storing a Flat or Spare Tire and Tools
(STS Only)...............................................5-92
Compact Spare Tire (STS Only).....................5-94
Appearance Care............................................5-94
Cleaning the Inside of Your Vehicle.................5-94
Fabric/Carpet...............................................5-96
Leather.......................................................5-96
Instrument Panel, Vinyl, and Other
Plastic Surfaces........................................5-97
Wood Panels...............................................5-97
Speaker Covers............................................5-97
Care of Safety Belts......................................5-97Weatherstrips...............................................5-97
Washing Your Vehicle...................................5-98
Cleaning Exterior Lamps/Lenses.....................5-98
Finish Care..................................................5-98
Windshield and Wiper Blades.........................5-99
Aluminum or Chrome-Plated Wheels................5-99
Tires.........................................................5-100
Sheet Metal Damage...................................5-100
Finish Damage...........................................5-101
Underbody Maintenance...............................5-101
Chemical Paint Spotting...............................5-101
Vehicle Care/Appearance Materials................5-102
Vehicle Identication.....................................5-103
Vehicle Identication Number (VIN)................5-103
Service Parts Identication Label...................5-103
Electrical System..........................................5-104
Add-On Electrical Equipment.........................5-104
Headlamp Wiring........................................5-104
Windshield Wiper Fuses...............................5-104
Power Windows and Other Power Options......5-105
Fuses and Circuit Breakers..........................5-105
Underhood Fuse Block................................5-106
Rear Underseat Fuse Block..........................5-110
Capacities and Specications........................5-116
Section 5 Service and Appearance Care
5-2

Low-Prole Performance Tires
If your vehicle has P255/45R18 99Y size tires on the
front wheels and P275/40R19 100Y size tires on the rear
wheels, 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 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 5-72.
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.
5-57

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.
(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
seeUniform 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. Passenger (P-Metric) Tire Example
5-58

(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 compact spare tire,
seeCompact Spare Tire (STS Only) on page 5-94and
If a Tire Goes Flat on page 5-81.(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 see
Ination - Tire Pressure on page 5-64.
(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. Compact Spare Tire Example
5-59

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.
5-60

Occupant Distribution:Designated seating positions.
Outward Facing Sidewall:The side of an
asymmetrical tire that has a particular side that faces
outward when mounted on a vehicle. The side of the
tire that contains a whitewall, bears white lettering,
or bears manufacturer, brand, and/or model name
molding that is higher or deeper than the same moldings
on the other sidewall of the tire.
Passenger (P-Metric) Tire:A tire used on passenger
cars and some light duty trucks and multipurpose
vehicles.
Recommended Ination Pressure:Vehicle
manufacturer’s recommended tire ination pressure as
shown on the tire placard. SeeInation - Tire Pressure on
page 5-64andLoading Your Vehicle on page 4-32.
Radial Ply Tire:A pneumatic tire in which the ply cords
that extend to the beads are laid at 90 degrees to the
centerline of the tread.
Rim:A metal support for a tire and upon which the tire
beads are seated.
Sidewall:The portion of a tire between the tread and
the bead.
Speed Rating:An alphanumeric code assigned to a
tire indicating the maximum speed at which a tire
can operate.Traction:The friction between the tire and the road
surface. The amount of grip provided.
Tread:The portion of a tire that comes into contact
with the road.
Treadwear Indicators:Narrow bands, sometimes
called wear bars, that show across the tread of a tire
when only 1/16 inch (1.6 mm) of tread remains.
SeeWhen It Is Time for New Tires on page 5-71.
UTQGS (Uniform Tire Quality Grading Standards):
A tire information system that provides consumers
with ratings for a tire’s traction, temperature, and
treadwear. Ratings are determined by tire manufacturers
using government testing procedures. The ratings are
molded into the sidewall of the tire. SeeUniform
Tire Quality Grading on page 5-75.
Vehicle Capacity Weight:The number of designated
seating positions multiplied by 150 lbs (68 kg) plus
the rated cargo load. SeeLoading Your Vehicle
on page 4-32.
Vehicle Maximum Load on the Tire:Load on an
individual tire due to curb weight, accessory weight,
occupant weight, and cargo weight.
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 4-32.
5-62

If a low tire pressure condition is detected, the TPMS
will display the CHECK TIRE PRESSURE warning
message on the DIC and, at the same time, illuminate
the low tire pressure warning symbol, on the instrument
panel cluster.
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.)
As an added safety
feature, your vehicle has
been equipped with a
tire pressure monitoring
system (TPMS) that
illuminates a low tire
pressure telltale when
one or more of your tires is
signicantly under-inated.
Accordingly, when the low tire pressure telltale
illuminates, you should stop and check your tires as soon
as possible, and inate them to the proper pressure.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.
Please note that the TPMS is not a substitute for proper
tire maintenance, and it is the driver’s responsibility to
maintain correct tire pressure, even if under-ination
has not reached the level to trigger illumination of
the TPMS low tire pressure telltale.
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 4-32for an example of the tire
and loading information label and its location on
your vehicle. Also seeInation - Tire Pressure on
page 5-64.
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 5-70andTires on page 5-56.
Notice:Do not use a tire sealant if your vehicle
has Tire Pressure Monitors. The liquid sealant can
damage the tire pressure monitor sensors.
5-67

Tire Inspection and Rotation
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.
P235/50R18 size tires on the front wheels and
P255/45R18 size tires on the rear wheels.
P255/45R18 size tires on the front wheels and
P275/40R19 size tires on the rear wheels.
Different tire sizes should not be rotated front to rear.
Each tire and wheel should only be used in the original
front or rear position it is in.
Tire rotation is recommended if your vehicle is equipped
with P235/50R17 size tires on all four wheel positions
or 255/45ZR18 size tires on all four wheel positions.
These tires should be rotated every 5,000 to 8,000 miles
(8 000 to 13 000 km)
Any time you notice unusual wear, rotate your tires as
soon as possible and check wheel alignment. Also
check for damaged tires or wheels. SeeWhen It Is Time
for New Tires on page 5-71andWheel Replacement
on page 5-76for more information.The purpose of regular rotation is to achieve more
uniform wear for all tires on the vehicle. The rst rotation
is the most important. SeeScheduled Maintenance
on page 6-4.
When rotating P235/50R17 size tires or 255/45ZR18
size tires, always use the correct rotation pattern
shown here.
If your vehicle has a compact spare tire, do not include
the compact spare tire in the tire rotation.
After the tires have been rotated, adjust the front and
rear ination pressures as shown on the Tire and
Loading Information label.
5-70

Vehicles that have the Tire Pressure Monitor System
(TPMS) will need to have the TPMS sensors reset after
a tire rotation, seeTire Pressure Monitor System on
page 5-66.
Make certain that all wheel nuts are properly tightened.
See “Wheel Nut Torque” underCapacities and
Specications on page 5-116.
{CAUTION:
Rust or dirt on a wheel, or on the parts to
which it is fastened, can make wheel nuts
become loose after a time. The wheel could
come off and cause an accident. When you
change a wheel, remove any rust or dirt from
places where the wheel attaches to the vehicle.
In an emergency, you can use a cloth or a
paper towel to do this; but be sure to use a
scraper or wire brush later, if needed, to get all
the rust or dirt off. SeeChanging a Flat Tire
(STS Only) on page 5-83.
When It Is Time for New Tires
One way to tell when it is
time for new tires is to
check the treadwear
indicators, which will
appear when your tires
have only 1/16 inch
(1.6 mm) or less of tread
remaining.
You need a new tire if any of the following statements
are true:
You can see the indicators at three or more places
around the tire.
You can see cord or fabric showing through the
tire’s rubber.
The tread or sidewall is cracked, cut, or snagged
deep enough to show cord or fabric.
The tire has a bump, bulge, or split.
The tire has a puncture, cut, or other damage that
cannot be repaired well because of the size or
location of the damage.
5-71