2007 CADILLAC STS wheel size

Tires............................................................ 421
Winter Tires.............................................. 422
Tire Sidewall Labeling............................... 423
Tire Terminology and Denitions............... 426
Run-Flat Tires (STS-V).............................. 429
Ination - Tire Pressure............................. 431
High-Speed Operation............................... 432
Tire Pressure Monitor System................... 433
Tire Inspection and Rotation...................... 438
When It Is Time for New Tires.................. 440
Buying New Tires...................................... 441
Different Size Tires and Wheels................ 443
Uniform Tire Quality Grading..................... 444
Wheel Alignment and Tire Balance............ 445
Wheel Replacement.................................. 445
Tire Chains............................................... 447
Lifting Your Vehicle (STS-V)...................... 448
If a Tire Goes Flat.................................... 451
Tire Inator Kit.......................................... 452
Changing a Flat Tire................................. 464
Removing the Spare Tire and Tools.......... 465
Removing the Flat Tire and Installing
the Spare Tire....................................... 466Storing a Flat or Spare Tire and Tools...... 473
Compact Spare Tire.................................. 475
Appearance Care........................................ 476
Cleaning the Inside of Your Vehicle.......... 476
Fabric/Carpet............................................. 477
Leather...................................................... 478
Instrument Panel, Vinyl, and Other
Plastic Surfaces..................................... 479
Wood Panels............................................. 479
Speaker Covers........................................ 479
Care of Safety Belts.................................. 479
Weatherstrips............................................ 480
Washing Your Vehicle............................... 480
Cleaning Exterior Lamps/Lenses................ 480
Finish Care............................................... 481
Windshield and Wiper Blades.................... 481
Aluminum or Chrome-Plated Wheels......... 482
Tires......................................................... 483
Sheet Metal Damage................................. 483
Finish Damage.......................................... 483
Underbody Maintenance............................ 483
Chemical Paint Spotting............................ 484
Vehicle Care/Appearance Materials............ 484
Section 5 Service and Appearance Care
360

Low-Prole Performance Tires
If your vehicle has 255/45ZR18, P255/45R18 or
P275/40R19 100Y 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 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 overallperformance 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 for details regarding winter tire
availability and proper tire selection. Also,
seeBuying New Tires on page 441.
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.
422

(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/transaxle, 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.
426

Your vehicle has also been equipped with a TPMS
malfunction indicator to indicate when the
system is not operating properly. The TPMS
malfunction indicator is combined with the low tire
pressure telltale. When the system detects a
malfunction, the telltale will ash for approximately
one minute and then remain continuously
illuminated. This sequence will continue upon
subsequent vehicle start-ups as long as the
malfunction exists.
When the malfunction indicator is illuminated, the
system may not be able to detect or signal low
tire pressure as intended. TPMS malfunctions may
occur for a variety of reasons, including the
installation of replacement or alternate tires or
wheels on the vehicle that prevent the TPMS from
functioning properly. Always check the TPMS
malfunction telltale after replacing one or more
tires or wheels on your vehicle to ensure that the
replacement or alternate tires and wheels allow
the TPMS to continue to function properly.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 349
for an example of the Tire and Loading
Information label and its location on your vehicle.
Also seeInation - Tire Pressure on page 431.
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 438andTires on page 421.
Notice:Your vehicle has a Tire Pressure
Monitor System (TPMS). Use only the
GM-provided tire sealant. Other liquid tire
sealants may damage the tire pressure
sensors.
435

This device complies with RSS-210 of Industry
Canada. Operation is subject to the following
two conditions:
1. This device may not cause interference.
2. This device must accept any interference
received, including interference that may
cause undesired operation of the device.
Changes or modications to this system by other
than an authorized service facility could void
authorization to use this equipment.
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 440
andWheel Replacement on page 445for
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 505.
438

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.
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 433.Make certain that all wheel nuts are properly
tightened. See “Wheel Nut Torque” under
Capacities and Specications on page 498.
{CAUTION:
Rust or dirt on a wheel, or on the parts to
which it is fastened, can make wheel nuts
become loose after 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 on page 464.
439

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
snow tires with a lower speed rating, never exceed
the tire’s maximum speed capability.
{CAUTION:
Mixing tires could cause you to lose
control while driving. If you mix tires of
different sizes (other than those originally
installed on your vehicle), brands, or
types (radial and bias-belted tires), the
vehicle may not handle properly, and you
could have a crash. Using tires of
different sizes (other than those originally
installed on your vehicle), brands, or
types may also cause damage to your
vehicle. Be sure to use the correct size,
brand, and type of tires on all wheels. It is
all right to drive with your vehicle’s
compact spare temporarily, it was
developed for use on your vehicle. See
Compact Spare Tire on page 475.
{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.
If you must replace your vehicle’s tires with those
that do not have a TPC Spec number, make
sure they are the same size, load range, speed
rating, and construction type (radial and
bias-belted tires) as your vehicle’s original tires.
Vehicles that have a tire pressure monitoring
system may give an inaccurate low-pressure
warning if non-TPC Spec rated tires are installed
on it. Non-TPC Spec rated tires may give a
low-pressure warning that is higher or lower than
the proper warning level you would get with
TPC Spec rated tires. SeeTire Pressure Monitor
System on page 433.
442

Your vehicle’s original equipment tires are listed
on the Tire and Loading Information label.
This label is attached to the vehicle’s center pillar
(B-pillar). SeeLoading Your Vehicle on page 349,
for more information about the Tire and Loading
Information label and its location on your vehicle.
Vehicles that have performance tires
P235/50R17 95V (front axle) and P255/45R17 98V
(rear axle) are mounted on wheels with different
rim widths. The front axle tires are mounted
on rims 7.5 inches (19.05 cm) wide and the rear
axle tires require wheels with a minimum rim width
of 8 inches (20.32 cm). The original equipment
wheels designed for P255/45R17 98V size
tires are etched with the words REAR ONLY.
When replacing P255/45R17 98V size tires have
them mounted on wheels with a minimum width of
8 inches (20.32 cm) and marked REAR ONLY.
SeeWheel Replacement on page 445.
Different Size Tires and Wheels
If you add wheels or tires that are a different size
than your original equipment wheels and tires,
this may affect the way your vehicle performs,
including its braking, ride and handling
characteristics, stability, and resistance to rollover.Additionally, if your vehicle has electronic systems
such as, anti-lock brakes, traction control, and
electronic stability control, the performance
of these systems can be affected.
{CAUTION:
If you add different sized wheels, your
vehicle may not provide an acceptable
level of performance and safety if tires not
recommended for those wheels are
selected. You may increase the chance
that you will crash and suffer serious
injury. Only use GM specic wheel and
tire systems developed for your vehicle,
and have them properly installed by a GM
certied technician.
SeeBuying New Tires on page 441and
Accessories and Modications on page 363for
additional information.
443