2005 CADILLAC STS spare tire

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 5-67andWheel Replacement
on page 5-71for 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 or 255/45ZR18 size tires,
always use the correct rotation pattern shown here.Do not include the compact spare tire in your 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 equipped with the Tire Pressure Monitor (TPM)
system will need to have the sensors reset after a tire
rotation, seeTire Pressure Monitor System on
page 5-62.
Make certain that all wheel nuts are properly tightened.
See “Wheel Nut Torque” underCapacities and
Specications on page 5-106.
5-66

{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) 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) may also cause damage to your
vehicle. Be sure to use the correct size and
type tires on all wheels. It is all right to drive
with your compact spare temporarily, it was
developed for use on your vehicle. See
Compact Spare Tire on page 5-84.
{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.
Vehicles equipped with 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 5-71.
5-69

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.)
The grades are molded on the sidewalls of most
passenger car tires. The Uniform Tire Quality Grading
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.
5-70

Removing the Spare Tire and Tools
The equipment you will need is in the trunk.
To gain access to the spare tire and jacking equipment,
do the following:
1. Open the trunk. SeeTrunk on page 2-14for more
information.
2. Remove the compact spare tire cover.
3. Turn the nut holding the jack counterclockwise and
remove it. Then remove the jack and wheel wrench.
4. Remove the compact spare tire. SeeCompact
Spare Tire on page 5-84for more information
about the compact spare tire.
5-76

The tools you will be using include the jack (A) and the
wheel wrench (B).
Removing the Flat Tire and
Installing the Spare Tire
If your vehicle has wheel covers, use the at end of the
wheel wrench to remove the covers. Turn the wheel
wrench clockwise to gently pry off the wheel cover.
Be careful not to scratch the aluminum wheel edge and
do not try to remove the wheel cover with your hands.
5-77

If your vehicle has wheel nut caps, turn the wheel
wrench counterclockwise to remove the caps.
Once the wheel cover and wheel nut caps have been
removed, use the following steps to remove the at tire
and install the spare tire.1. Place the wheel wrench (A) securely over the wheel
nut (B). Turn the wheel wrench counterclockwise to
loosen all the wheel nuts. Do not remove them yet.
5-78

5. Raise the jack by turning the wheel wrench
clockwise until the slots in the jack head t into the
metal ange located behind the triangle on the
plastic molding as shown.
6. Put the compact spare tire near you.7. Raise the vehicle by turning the wheel wrench
clockwise. Raise the vehicle far enough off the
ground for the compact spare tire to t under the
vehicle.
8. Remove all the wheel nuts and take off the at tire.
{CAUTION:
Rust or dirt on the wheel, or on the parts to
which it is fastened, can make the 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
the 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 you need to,
to get all the rust or dirt off.
5-80

9. Remove any rust or dirt
from the wheel bolts,
mounting surfaces
and spare wheel.
{CAUTION:
Never use oil or grease on studs or nuts. If
you do, the nuts might come loose. Your wheel
could fall off, causing a serious accident.
10. Place the compact spare tire on the wheel-mounting
surface.11. Put the wheel nuts
back on with the
rounded end of the
nuts toward the wheel.
12. Tighten each wheel nut by turning it clockwise with
your hand until the wheel is held against the hub.
5-81