1996 GMC SAVANA Owners Manual

Tires CAU’ ON: (Continued)
We don’t make tires. Your new vehicle comes with
high-quality tires made by
a leading tire manufacturer. If
you ever have questions about your tire warranty and
where
to obtain service, see your GM Warranty booklet
for details.
1
Poorly maintained and improperly used tires
are dangerous.
Overloading your tires can cause
overheating as
a result of too much friction.
You could have an air-out and a serious
accident. See “Loading Your Vehicle’’ in
the Index.
CAUTION: (Continued)
0
0
0
Underinflated tires pose the same danger as
overloaded tires. The resulting accident
could cause serious injury. Check all tires
frequently to maintain the recommended pressure. Tire pressure should be checked
when your tires are cold.
Overinflated tires are more likely to be
cut, punctured or broken by
a sudden
impact
-- such as when you hit a pothole.
Keep tires at the recommended pressure.
Worn,
old tires can cause accidents. If your
tread is badly worn, or if your tires have
been damaged, replace them.
6-41
ProCarManuals.com

Inflation -- Tire Pressure
The Certification/Til-e-~ label, which is on the rear edge of
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 1mre than
1 mile (1.6 ktn).
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:
0 Too much flexing
Too much heat
0 Tire overloading
Bad wear
0 Bad handling
Bad fuel economy.
NOTICE: (Continued)
I NOTICE: (Continued) I
If your tires have too much air (overinflation),
you can get the following:
0 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.
Haw to Check
Use a
good quality pocket-type gage to check tire
pressure.
You can’t tell if yom 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.
6-42
ProCarManuals.com

nspectior
1 Ires should be inspected every 6,000 to 8,000 miles
(I 0 000 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.
If your vehicle has dual rear wheels,
also see “Dual Tire Operation“ later
in this section.
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.
If your vehicle has single rear wheels, always use one of
the correct rotation patterns shown here when rotating
your tires.
If your vehicle has dual rear wheels, always use one of
FRT FRT the. correct rotation patterns shown here when rotating
KC
your tires.
When you install dual wheels, be sure the vent
holes in
the inner and outer wheels on each side are lined up.
After the tires have been rotated, adjust the front and
rear inflation pressures as shown on
the
CertificatidTire label. Make certain that all wheel nuts
are properly tightened. See “Wheel
Nut Torque” in
the Index.
6-43
ProCarManuals.com

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.
Some commercial truck
tires may
not have
treadwear indicators.
You need a new tire if any of the following statements
are true:
0 You can see the indicators at three or more places
0 You can see cord or fabric showing through the
tire’s rubber.
0 The tread or sidewall is cracked, cut or snagged deep
enough to
show cord or fdbric.
0 The tire has a bump, bulge or split.
The tire has a puncture, cut or other damage that
around the
tire.
can’t
be repaired well because of the size or location
of the damage.
6-44
ProCarManuals.com

Dual Tire Operation
When the vehicle is new, or whenever a wheel, wheel
bolt or wheel
nut is replaced, check the wheel nut torque
after
100, 1,000 and 6,000 miles ( 160, 1 600 and
10 000 km) of driving. For proper torque, see “Wheel
Nut Torque”
in the Index.
The outer tire
on a dual wheel setup generally wears
faster than
the inner tire. Your tires will wear more
evenly and last longer if
you rotate the tires periodically.
If you’re going to be doing a lot of driving on
high-crown roads, you can reduce tire wear by adding
5 psi (35 kPa) to the tire pressure in the outer tires. Be
sure to return
to the recommended pressures when no
longer driving under those conditions. See “Changing a
Flat Tire” in the Index for more information.
A CAUTION:
If you operate your vehicle with a tire that is
badly underinflated, the tire can overheat. An
overheated tire can lose air suddenly
or catch
fire. You or others could be injured. Be sure all
tires (including the spare) are properly inflated.
Buying New Tires
To find out what kind and size of tires you need, look at
the Certification/Tire 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.
ProCarManuals.com

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.
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
(TYC) standards.
6-46
ProCarManuals.com

Treadwear Temperature -- A, B, C
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 governrnent course as a tire
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.
b oraded 100. The relative performance of tires depends
Traction -- A, B, C
The traction grades, from 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 pelformance.
Warning: The traction grade assigned to
this tire is based
on braking (straightahead) traction tests and does not
include cornering (turning) traction. 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 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 ca~w heat. buildup and possible tire failure.
6-47
ProCarManuals.com

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.
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
GM dealer if any of these conditions exist.
Your dealer will know the kind of wheel
you need. 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.
4 CAUTION:
r-
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.
6-48
ProCarManuals.com