1994 CHEVROLET SUBURBAN Owners Manual

Never exceed the GVWR for your vehicle, or the GAWR for either the front
or rear axle.
And, if you do have a heavy load, you should spread it out.
Using heavier suspension components to get added durability might not
change your weight ratings. Ask your dealer to help
you load your vehicle
the right way.
NOTICE:
Your warranty does not cover parts or components that fail
because
of overloading.
If you put things inside your vehicle-like suitcases, tools, packages, or
anything else-they go as fast as the vehicle goes. If you have to stop or
turn quickly, or if there is a crash, they’ll keep going.
ProCarManuals.com

Trailering Package
If your vehicle comes with the Trailering Package, there is also a load rating
which includes the weight
of the vehicle and the trailer it tows. This rating
is called the Gross Combination Weight Rating (GCWR).
When you weigh your trailer, be sure to include the weight
of everything
you put in it. And, remember
to figure the weight of the people inside as
part of your
load.
Your dealer can help you determine your GCWR.
Trailer Recommendations
You must subtract your hitch loads from the CWR for your vehicle. Weigh
your vehicle with the trailer hitch attached,
so that you won’t go over the
GVWR
or the GAWR.
You’ll get the best performance
if you spread out the weight of your load
the right way, and if you choose the correct hitch and trailer brakes.
For more information, see “Trailer Towing’’
in the Index.
Add-on Equipment
When you carry removable items, like snow plow blades, you may need to
put a limit on how many people you carry inside your vehicle. Be sure to
weigh your vehicle before you buy and install the new equipment.
~
NOTICE:
Your warranty doesn’t cover parts or components that fail
because
of overloading.
6-61 ProCarManuals.com

Tires
We don’t make tires. Your new vehicle comes with high quality tires made
by a leading tire manufacturer. These tires are warranted by the tire
manufacturers and their warranties are delivered with every
new vehicle. If
your spare tire is a different brand than your road tires, you will have a tire
warranty folder from each of
these manufacturers.
Inflation - Tire Pressure
The Certification/Tire label which is on the rear edge of the driver’s door, or
on the incomplete vehicle document in the cab, 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
a mile.
6-62
ProCarManuals.com

You can operate some vehicles at reduced inflation pressures only when
you’ll be carrying reduced loads. On those vehicles, the minimum cold
inflation pressures for a typical reduced load are printed on the “Improved
Ride Tire Pressure” label located on the driver’s door. Weigh the vehicle to
find the load on each tire and see the label for the minimum cold inflation
pressures for that load.
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:
Too much flexing
Too much heat
Tire overloading
Bad wear
Bad handling
Bad fuel economy.
If your tires have too much air (overinflation), you can get:
0 Unusual wear
Bad handling
Rough ride
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.
How to Check
Use a good quality pocket-type gage to check tire pressure. Simply looking
at the tires will not tell you the pressure, especially
if you have radial tires
- which may look properly inflated even if they’re underinflated.
If your tires have valve caps, be sure to put them back on. They help prevent
leaks by keeping out dirt and moisture.
ProCarManuals.com

Special Tire lnflation
If you have 16 inch tires on your vehicle, and:
- You’ll be driving for very long at speeds of 66 mph (105 kdh) to
75 mph (120 km/h) where legal, inflate tires to 10 psi (70 kPa)
more than the recommended cold inflation pressures.
- You’ll be driving for very long at speeds of 76 mph ( 120 kdh) to
85 mph (1 35 kdh) where legal, cold inflation pressures should be
increased by
10 psi (70 kPa) and you must also reduce axle load
capacity by 10%.
Do not drive over 85 mph (135 km/h) even if
it’s legal.
Inflation pressures should never exceed 10 psi (70 kPa) above the
inflation specified for the maximum load
of the tire.
Tire lnspection and Rotation
To make your tires last longer, have them inspected and rotated at the
mileages recommended
in the Maintenance Schedule. See “Scheduled
Maintenance Services” in the Index.
FRT FRT
Use this rotation
pattern.
If your vehicle has front tires with different load ratings or tread designs
(such
as all season vs. on/off road) than the rear tires, don’t rotate your tires
front
to rear.
After the tires have been rotated, adjust the front and rear inflation pressure
as shown on the Certificationmire label. Make certain that all wheel nuts are
properly tightened. See “Wheel Nut Torque” in the Index.
6-64
ProCarManuals.com

When /t ’s Time for New Tires
-L
E
TREAD WEAR
INDICATORS
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
2/32 inch
(1.6 mm) or less of
tread remaining.
You need a uew tire if
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.
0 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.
6-65 ProCarManuals.com

Buying New Tires
To find out what kind and size of tires you need, look at the
CertificatiodTire 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 a “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.
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.)
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.
6-66 ProCarManuals.com

Traction - A, B, C
The traction grades, from highest to lowest are: A, B, and C. 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
(straight-ahead) traction tests and does not include cornering (turning)
traction.
Temperature - A, By 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 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.
These grades are molded on the sidewalls of passenger car tires.
While the tires available as standard or optional equipment on General
Motors vehicles may vary with respect to these grades, all such tires meet
General Motors performance standards and have been approved for use on
General Motors vehicles. All passenger type
(P Metric) tires must conform
to Federal safety requirements in addition to these grades.
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.
6-67 ProCarManuals.com