2007 CADILLAC STS tires

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

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 (NHTSA), 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 (UTQG)
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.
Treadwear
The treadwear grade is a comparative rating based
on the wear rate of the tire when tested under
controlled conditions on a specied government
test course. For example, a tire graded 150 would
wear one and a half (1.5) times as well on the
government course as a tire graded 100. The
relative performance of tires depends upon the
actual conditions of their use, however, and may
depart signicantly from the norm due to variations
in driving habits, service practices, and differences
in road characteristics and climate.
Traction – AA, A, B, C
The traction grades, from highest to lowest, are
AA, A, B, and C. Those grades represent the tire’s
ability to stop on wet pavement as measured under
controlled conditions on specied government test
surfaces of asphalt and concrete. A tire marked
C may have poor traction performance.
Warning:The traction grade assigned to this tire
is based on straight-ahead braking traction
tests, and does not include acceleration, cornering,
hydroplaning, or peak traction characteristics.
444

Temperature – A, B, C
The temperature grades are A (the highest),
B, and C, representing the tire’s resistance to the
generation of heat and its ability to dissipate
heat when tested under controlled conditions on a
specied indoor laboratory test wheel. Sustained
high temperature can cause the material of the tire
to degenerate and reduce tire life, and excessive
temperature can lead to sudden tire failure.
The grade C corresponds to a level of performance
which all passenger car tires must meet under
the Federal Motor Vehicle Safety Standard
No. 109. Grades B and A represent higher levels
of performance on the laboratory test wheel
than the minimum required by law.
Warning:The temperature grade for this tire is
established for a tire that is properly inated
and not overloaded. Excessive speed,
underination, or excessive loading, either
separately or in combination, can cause heat
buildup and possible tire failure.
Wheel Alignment and Tire Balance
The tires and wheels on your vehicle were aligned
and balanced carefully at the factory to give you
the longest tire life and best overall performance.
Adjustments to wheel alignment and tire
balancing will not be necessary on a regular basis.
However, if you notice unusual tire wear or your
vehicle pulling to one side or the other, the
alignment may need to be checked. If you notice
your vehicle vibrating when driving on a smooth
road, your tires and wheels may need to be
rebalanced. See your dealer for proper diagnosis.
Wheel Replacement
Replace any wheel that is bent, cracked, or badly
rusted or corroded. If wheel nuts keep coming
loose, the wheel, wheel bolts, and wheel
nuts should be replaced. If the wheel leaks air,
replace it (except some aluminum wheels,
which can sometimes be repaired). See your
dealer if any of these conditions exist.
Your dealer will know the kind of wheel you need.
445

Each new wheel should have the same
load-carrying capacity, diameter, width, offset and
be mounted the same way as the one it
replaces.
If you need to replace any of your wheels, wheel
bolts, or wheel nuts, replace them only with
new GM original equipment parts. This way, you
will be sure to have the right wheel, wheel
bolts, and wheel nuts for your vehicle.
{CAUTION:
Using the wrong replacement wheels,
wheel bolts, or wheel nuts on your vehicle
can be dangerous. It could affect the
braking and handling of your vehicle,
make your tires lose air and make you
lose control. You could have a collision in
which you or others could be injured.
Always use the correct wheel, wheel bolts,
and wheel nuts for replacement.Notice:The wrong wheel can also cause
problems with bearing life, brake cooling,
speedometer or odometer calibration,
headlamp aim, bumper height, vehicle ground
clearance, and tire or tire chain clearance
to the body and chassis.
SeeChanging a Flat Tire on page 464for more
information.
Used Replacement Wheels
{CAUTION:
Putting a used wheel on your vehicle is
dangerous. You cannot know how it has
been used or how far it has been driven. It
could fail suddenly and cause a crash. If
you have to replace a wheel, use a new
GM original equipment wheel.
446

Tire Chains
{CAUTION:
If your vehicle has P255/45R17,
P255/45R18, P275/40R19, or 255/45ZR18
size tires, do not use tire chains, as 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.
CAUTION: (Continued)
CAUTION: (Continued)
To help avoid damage to your vehicle,
drive slowly, readjust, or remove the
device if it is contacting your vehicle, and
do not spin your vehicle’s wheels.
If you do nd traction devices that will t,
install them on the rear tires only.
Notice:If your vehicle has P235/50R17 95S
size tires, use tire chains only where legal and
only when you must. Use only SAE Class
S-type chains that are the proper size for your
tires. Install them on the rear tires and
tighten them as tightly as possible with the
ends securely fastened. Drive slowly and follow
the chain manufacturer’s instructions. If you
can hear the chains contacting your vehicle,
stop and retighten them. If the contact
continues, slow down until it stops. Driving
too fast or spinning the wheels with chains on
will damage your vehicle.
447

Lifting From the Front
The front lifting points can be accessed from
either side of your vehicle, behind the front tires.
1. Locate the front lifting points using the
diagram above. The front lifting location
is about 15 inches (37 cm) from the rear edge
of the front wheel well.
2. Be sure to place a block or pad between the
jack and the vehicle.
3. Lift the vehicle with the jack, making sure the
jack is centered on the front lifting point.
Lifting From the Rear
The rear lifting points can be accessed from either
side of your vehicle, in front of the rear tires.
1. Locate the rear lifting points using the
diagram above. The rear lifting location
is about 7 inches (17 cm) from the front edge
of the rear wheel well.
2. Be sure to place a block or pad between the
jack and the vehicle.
3. Lift the vehicle with the jack, making sure the
jack is centered on the rear lifting point.
SeeDoing Your Own Service Work on page 364.
450

If a Tire Goes Flat
It is unusual for a tire to blowout while you are
driving, especially if you maintain your tires
properly. SeeTires on page 421. If air goes out of
a tire, It is 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 would 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.If a tire goes at, and your vehicle has a compact
spare tire, seeChanging a Flat Tire on page 464.
This information shows you how to use your
vehicle’s tire changing equipment and how
to change a at tire safely.
{CAUTION:
Lifting a vehicle and getting under it to do
maintenance or repairs is dangerous
without the appropriate safety equipment
and training. The jack provided with your
vehicle is designed only for changing a
at tire. If it is used for anything else, you
or others could be badly injured or killed
if the vehicle slips off the jack. Use the
jack provided with your vehicle only for
changing a at tire.
If your vehicle has 255/45ZR18 size tires, there is
no spare tire, jack, or tire changing equipment.
A tire inator kit, included with your vehicle, may
be used to seal small punctures in the tread
area of the tire. SeeTire Inator Kit on page 452.
451

Run-Flat Tires (STS-V)
If your vehicle has run-at tires, there is no spare
tire and no tire changing equipment. Run-at
tires can operate effectively with no air pressure
for a limited distance and speed. These tires
perform so well without any air pressure that a Tire
Pressure Monitor (TPM) is used to alert you
when there is a low tire condition.
{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.SeeRun-Flat Tires (STS-V) on page 429andTire
Pressure Monitor System on page 433, for
additional information.
{CAUTION:
Special tools and procedures are required
to service a run-at tire. If these special
tools and procedures are not used you or
others could be injured and your vehicle
could be damaged. Always be sure the
proper tools and procedures, as described
in the service manual, are used.
To order a service manual seeService
Publications Ordering Information on page 543.
Tire Inator Kit
Your vehicle has a tire inator kit. There is no jack
or spare tire. The kit uses a liquid tire sealant
and air at the same time to seal small punctures
in the tread area of the tire. Be sure to read
and follow all of the tire inator kit instructions.
452