Page 257 of 306

Downloaded from www.Manualslib.com manuals search engine Inflation -- Tire Pressure
The Tire-Loading Information label, which is located on
the driver’s door, shows the correct inflation pressures
for your tires when they’re cold. “Cold” means your
vehicle has been sitting for at least three hours or driven
no more than 1 mile
(1.6 km).
NOTICE: ~~~ ~~
Don’t let anyone tell you that underinflation or
overinflation is all right. It’s not. If your tires
don’t have enough
air (underinflation), you can
get the
following:
Too much flexing
0 Too much heat
0 Tire overloading
Bad wear
0 Bad handling
0 Bad fuel economy.
NOTICE: (Continued) NOTICE: (Continued)
If your
tires have too much air (overinflation),
you can get the following:
Unusual wear
0 Bad handling
0 Rough ride
0 Needless damage from road hazards.
When to Check
Check your tires once a month or more. Also, check the
tire pressure
of the spare tire.
If you have a compact spare tire, it should be at
60 psi
(420 Ea).
HQW to Check
Use a good quality pocket-type gage to check tire
pressure. You can’t tell
if your tires are properly inflated
simply by looking at them, Radial tires
may look
properly inflated even when they’re underinflated.
Be sure to put the valve caps back on the valve stems.
They help prevent leaks by keeping out
dirt and moisture.
Page 258 of 306
Downloaded from www.Manualslib.com manuals search engine Tire Inspection and Rotation
Tires should be inspected every 6,000 to 8,000 miles
(10 000 to 13 000 km) for any signs of unusual wear. If
unusual wear is present, rotate your tires as soon as
possible and check wheel alignment. Also check for
damaged tires or wheels. See “When It’s Time for New
Tires” and “Wheel Replacement” later in this section for
more information.
J.
Q
The purpose of regular rotation is to achieve more
uniform wear for all tires on the vehicle. The first
rotation is the most important. See “Scheduled
Maintenance Services” in the Index for scheduled
rotation intervals.
When rotating your tires, always use one
of the correct
rotation patterns shown here.
If your vehicle has a compact spare tire, don’t include it
in your tire rotation.
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Page 259 of 306

Downloaded from www.Manualslib.com manuals search engine After the tires have been rotated, adjust the front and
rear inflation pressures
as shown on the Tire-Loading
Information label. Make certain that all wheel nuts are
properly tightened. See “Wheel Nut Torque” in
the Index.
A 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 you
need to, to get all the rust or
dirt off. (See
“Changing
a Flat Tire” in the Index.) When It’s Time
for New
Tires
... .
One way to tell when it’s
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 folllowing statements
are true:
0
0
0
0
0
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
can’t be repaired well because
of the size or location
of the damage.
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Page 260 of 306

Downloaded from www.Manualslib.com manuals search engine Buying New Tires
To find out what kind and size of tires you need, look at
the Tire-Loading Information label.
The tires installed on your vehicle when it was new had
a Tire Performance Criteria Specification (TPC Spec)
number on each tire’s sidewall. When you get new tires,
get ones with that same TPC Spec number. That way
your vehicle will continue to have tires that are designed
to give proper endurance, handling, speed rating,
traction, ride and other things during normal service on
your vehicle. If your tires have an all-season tread
design, the TPC number will be followed by an “MS”
(for mud and snow).
If you ever replace your tires with those not having a
TPC Spec number, make sure they are the same size,
load range, speed rating and construction type (bias,
bias-belted or radial) as your original tires.
A CAUTION:
Mixing tires could cause you to lose control while
driving.
If you mix tires of different sizes or types
(radial and bias-belted tires), the vehicle may not
handle properly, and you could have a crash.
Using tires of different sizes may also cause
damage to your vehicle. Be sure to use the same
size and type tires on all wheels.
It’s all right to drive with your compact spare
(if you have one). It was developed for use on
your vehicle.
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Page 261 of 306

Downloaded from www.Manualslib.com manuals search engine Uniform Tire Quality Grading
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 specified government test course. For
example, a tire graded 150 would wear one and a half
(1 1/2) 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 significantly from the norm due to variations
in driving habits, service practices and differences in
road characteristics and climate.
Traction -- A, B, C
The traction grades, kom highest to lowest, are A, B, and
C, and they represent the tire’s ability to stop on wet
pavement as measured under controlled conditions on specified 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 braking (straightahead) traction tests and does not
include cornering (turning) traction.
Page 262 of 306

Downloaded from www.Manualslib.com manuals search engine 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 condtions on a specified 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 inflated and not
overloaded. Excessive speed, underinflation, or
excessive loading, either separately or in combination,
can cause heat buildup and possible tire failure.
Wheel Alignment and Tire Balance
The wheels on your vehicle were aligned and balanced
carefully at the factory to give you the longest tire life
and best overall performance.
In most cases, you will not need to have your wheels
aligned again. However, if you notice unusual tire wear
or your vehicle pulling one way or the other, the
alignment may need to be reset. If you notice your
vehicle vibrating when driving on a smooth road, your
wheels may need to be rebalanced.
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Page 263 of 306

Downloaded from www.Manualslib.com manuals search engine 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
Cadillac dealer if any
of these conditions exist.
Your dealer will know the kind
of wheel you need.
Each new.whee1 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 h.ave the
right wheel, wheel bolts and wheel nuts for your
Cadillac model.
Using the wrong replacement w
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.
See “Changing a Flat Tire” in the Index for more
information.
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Page 264 of 306
Downloaded from www.Manualslib.com manuals search engine Used Replacement Wheels
~
Putting a used wheel on your vehicle is
dangerous. You can’t know how
it’s been used or
how many miles
it’s been driven. It could fail
suddenly and cause an accident.
If you have to
replace
a wheel, use a new GM original
equipment wheel.
Tire Chains
I NOTICE:
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.
6-47