Black plate (54,1)Chevrolet Express Owner Manual - 2012
10-54 Vehicle Care
Tire Terminology and
Definitions
Air Pressure:The amount of
air inside the tire pressing
outward on each square inch
of the tire. Air pressure is
expressed in kPa (kilopascal)
or psi (pounds per square inch).
Accessory Weight
:The
combined weight of optional
accessories. Some examples of
optional accessories are
automatic transmission, power
steering, power brakes, power
windows, power seats, and air
conditioning.
Aspect Ratio
:The relationship
of a tire's height to its width.
Belt
:A rubber coated layer of
cords that is located between
the plies and the tread. Cords
may be made from steel or other
reinforcing materials. Bead
:The tire bead contains
steel wires wrapped by steel
cords that hold the tire onto
the rim.
Bias Ply Tire
:A pneumatic tire
in which the plies are laid at
alternate angles less than
90 degrees to the centerline of
the tread.
Cold Tire Pressure
:
The amount of air pressure
in a tire, measured in
kPa (kilopascal) or psi (pounds
per square inch) before a tire
has built up heat from driving.
See Tire Pressure on
page 10‑56.
Curb Weight
:The weight of a
motor vehicle with standard and
optional equipment including the
maximum capacity of fuel, oil,
and coolant, but without
passengers and cargo. DOT Markings
:A code molded
into the sidewall of a tire
signifying that the tire is in
compliance with the U.S.
Department of Transportation
(DOT) Motor Vehicle Safety
Standards. The DOT code
includes the Tire Identification
Number (TIN), an alphanumeric
designator which can also
identify the tire manufacturer,
production plant, brand, and
date of production.
GVWR
:Gross Vehicle Weight
Rating. See Vehicle Load Limits
on page 9‑11.
GAWR FRT
:Gross Axle Weight
Rating for the front axle.
See Vehicle Load Limits on
page 9‑11.
GAWR RR
:Gross Axle Weight
Rating for the rear axle.
See Vehicle Load Limits on
page 9‑11.
Black plate (61,1)Chevrolet Express Owner Manual - 2012
Vehicle Care 10-61
.Operating electronic devices or
being near facilities using radio
wave frequencies similar to the
TPMS could cause the TPMS
sensors to malfunction.
If the TPMS is not functioning
properly, it cannot detect or signal a
low tire condition. See your dealer
for service if the TPMS malfunction
light and DIC message come on
and stay on.
TPMS Sensor Matching
Process
Each TPMS sensor has a unique
identification code. The identification
code needs to be matched to a
new tire/wheel position after rotating
the vehicle’ s tires or replacing one
or more of the TPMS sensors. Also,
the TPMS sensor matching process
should be performed after replacing
a spare tire with a road tire
containing the TPMS sensor.
The malfunction light and the DIC
message should go off at the next
ignition cycle. The sensors are
matched to the tire/wheel positions, using a TPMS relearn tool, in the
following order: driver side front tire,
passenger side front tire, passenger
side rear tire, and driver side rear.
See your dealer for service or to
purchase a relearn tool.
There are two minutes to match
the first tire/wheel position, and
five minutes overall to match all
four tire/wheel positions. If it takes
longer, the matching process stops
and must be restarted.
The TPMS sensor matching
process is:
1. Set the parking brake.
2. Turn the ignition to ON/RUN with
the engine off.
3. Press the Remote Keyless Entry (RKE) transmitter's LOCK
and UNLOCK buttons at the
same time for approximately
five seconds. The horn sounds
twice to signal the receiver is
in relearn mode and TIRE
LEARNING ACTIVE message
displays on the DIC screen. If the vehicle does not have
RKE, press the Driver
Information Center (DIC) vehicle
information button until the
PRESS
VTO RELEARN TIRE
POSITIONS message displays.
The horn sounds twice to signal
the receiver is in relearn mode
and TIRE LEARNING ACTIVE
message displays on the DIC
screen.
If the vehicle does not have RKE
or DIC buttons, press the trip
odometer reset stem located on
the instrument panel cluster until
the PRESS
VTO RELEARN
TIRE POSITIONS message
displays. The horn sounds twice
to signal the receiver is in
relearn mode and TIRE
LEARNING ACTIVE message
displays on the DIC screen.
4. Start with the driver side front tire.
Black plate (65,1)Chevrolet Express Owner Manual - 2012
Vehicle Care 10-65
SeeTire Inspection on page 10‑62
and Tire Rotation on page 10‑62 for
additional information.
The rubber in tires ages over time.
This also applies to the spare tire,
if the vehicle has one, even if it is
never used. Multiple conditions
including temperatures, loading
conditions, and inflation pressure
maintenance affect how fast aging
takes place. Tires will typically need
to be replaced due to wear before
they may need to be replaced
due to age. Consult the tire
manufacturer for more information
on when tires should be replaced.
Vehicle Storage
Tires age when stored normally
mounted on a parked vehicle. Park
a vehicle that will be stored for at
least a month in a cool, dry, clean
area away from direct sunlight to
slow aging. This area should be
free of grease, gasoline or other
substances that can deteriorate
rubber. Parking for an extended period can
cause flat spots on the tires that
may result in vibrations while
driving. When storing a vehicle for
at least a month, remove the tires or
raise the vehicle to reduce the
weight from the tires.
Buying New Tires
GM has developed and matched
specific tires for the vehicle.
The original equipment tires
installed were designed to meet
General Motors Tire Performance
Criteria Specification (TPC Spec)
system rating. When replacement
tires are needed, GM strongly
recommends buying tires with the
same TPC Spec rating.
GM's exclusive TPC Spec system
considers over a dozen critical
specifications that impact the
overall performance of the
vehicle, including brake system
performance, ride and handling,
traction control, and tire pressure
monitoring performance.
GM's TPC Spec number is molded
onto the tire's sidewall near the tire
size. If the tires have an all‐season
tread design, the TPC Spec number
will be followed by MS for mud and
snow. See
Tire Sidewall Labeling on
page 10‑50 for additional
information.
Black plate (67,1)Chevrolet Express Owner Manual - 2012
Vehicle Care 10-67
Vehicles that have a tire pressure
monitoring system could give an
inaccurate low‐pressure warning if
non‐TPC Spec rated tires are
installed. SeeTire Pressure Monitor
System on page 10‑58.
The Tire and Loading Information
label indicates the original
equipment tires on the vehicle.
See Vehicle Load Limits on
page 9‑11 for the label location and
more information about the Tire and
Loading Information label.Different Size Tires and
Wheels
If wheels or tires are installed that
are a different size than the original
equipment wheels and tires, vehicle
performance, including its braking,
ride and handling characteristics,
stability, and resistance to rollover
may be affected. If the vehicle has
electronic systems such as antilock
brakes, rollover airbags, traction
control, and electronic stability
control, the performance of these
systems can also be affected.
{WARNING
If different sized wheels are used,
there may not be an acceptable
level of performance and safety if
tires not recommended for those
wheels are selected. This
increases the chance of a crash
and serious injury. Only use GM
specific wheel and tire systems
developed for the vehicle, and
have them properly installed by a
GM certified technician.
See Buying New Tires on
page 10‑65 andAccessories and
Modifications on page 10‑3 for
additional information.
Black plate (70,1)Chevrolet Express Owner Manual - 2012
10-70 Vehicle Care
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.
Some aluminum wheels can be
repaired. See your dealer if any of
these conditions exist.
Your dealer will know the kind of
wheel that is needed.
Each new wheel should have the
same load-carrying capacity,
diameter, width, offset, and be
mounted the same way as the
one it replaces.
Replace wheels, wheel bolts, wheel
nuts, or Tire Pressure Monitor
System (TPMS) sensors with new
GM original equipment parts.{WARNING
Using the wrong replacement
wheels, wheel bolts, or wheel
nuts can be dangerous. It could
affect the braking and handling of
the vehicle. Tires can lose air,
and cause loss of control, causing
a crash. 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 If a Tire Goes Flat on
page 10‑72 for more information.
Used Replacement Wheels
{WARNING
Replacing a wheel with a used
one is dangerous. How it has
been used or how far it has been
driven may be unknown. It could
fail suddenly and cause a crash.
When replacing wheels, use a
new GM original equipment
wheel.
Black plate (71,1)Chevrolet Express Owner Manual - 2012
Vehicle Care 10-71
Tire Chains
{WARNING
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 the vehicle and
you or others may be injured in a
crash. To help avoid damage to
the vehicle, drive slowly, readjust,
or remove the device if it is
contacting the vehicle. Do not
spin the vehicle's tires. Follow the
manufacturer's instructions.Notice:
Use tire chains only
where legal and only when you
must. Use chains that are the
proper size for the tires. Install
them on the tires of the rear axle.
Do not use chains on the tires of
the front axle. 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 the 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 the vehicle. For Cutaway models with LT245/
75R16, LT225/75R16 or LT215/
85R16 size single or dual rear tires,
use Low Profile Z-Chain or SAE
Class S cables.
For Cargo or Passenger models
with P245/70R17, LT225/75R16 or
LT245/75R16 size tires, use Low
Profile Z-Chain cables. SAE Class S
chains are not recommended.
If the vehicle has dual rear tires,
do not use individual tire chains.
Use tire chains that fit across both
dual tires.
Black plate (72,1)Chevrolet Express Owner Manual - 2012
10-72 Vehicle Care
If a Tire Goes Flat
It is unusual for a tire to blow out
while driving, especially if the tires
are maintained properly. If air goes
out of a tire, it is much more likely to
leak out slowly. But if there ever is a
blowout, here are a few tips about
what to expect and what to do:
If a front tire fails, the flat tire
creates a drag that pulls the vehicle
toward that side. Take your foot off
the accelerator pedal and grip the
steering wheel firmly. Steer to
maintain lane position, and then
gently brake to a stop, well off the
road, if possible.
A rear blowout, particularly on a
curve, acts much like a skid and
may require the same correction as
used in a skid. Stop pressing the
accelerator pedal and steer to
straighten the vehicle. It may be
very bumpy and noisy. Gently brake
to a stop, well off the road,
if possible.{WARNING
Driving on a flat tire will cause
permanent damage to the tire.
Re-inflating a tire after it has
been driven on while severely
underinflated or flat may cause a
blowout and a serious crash.
Never attempt to re-inflate a tire
that has been driven on while
severely underinflated or flat.
Have your dealer or an authorized
tire service center repair or
replace the flat tire as soon as
possible.
{WARNING
Lifting a vehicle and getting
under it to do maintenance or
repairs is dangerous without the
appropriate safety equipment and
training. If a jack is provided with
the vehicle, it is designed only for
changing a flat tire. If it is used for
anything else, you or others could
be badly injured or killed if the
vehicle slips off the jack. If a jack
is provided with the vehicle, only
use it for changing a flat tire.
If a tire goes flat, avoid further tire
and wheel damage by driving slowly
to a level place, well off the road,
if possible. Turn on the hazard
warning flashers. See Hazard
Warning Flashers on page 6‑5.
Black plate (73,1)Chevrolet Express Owner Manual - 2012
Vehicle Care 10-73
{WARNING
Changing a tire can be
dangerous. The vehicle can slip
off the jack and roll over or fall
causing injury or death. Find a
level place to change the tire.
To help prevent the vehicle
from moving:1. Set the parking brake firmly.
2. Put an automatic transmission in P (Park) or a
manual transmission in
1 (First) or R (Reverse).
(Continued)
WARNING (Continued)
3. Turn off the engine and donot restart while the vehicle
is raised.
4. Do not allow passengers to remain in the vehicle.
5. Place wheel blocks on both sides of the tire at the
opposite corner of the tire
being changed. When the vehicle has a flat tire (B),
use the following example as a
guide to assist in the placement of
the wheel blocks (A).
A. Wheel Block
B. Flat Tire
The following information explains
how to repair or change a tire.