Page 420 of 636

loading may be required for high-speed vehicle opera-
tion. Refer to original equipment or an authorized tire
dealer for recommended safe operating speeds, loading
and cold tire inflation pressures.
WARNING!
High speed driving with your vehicle under maxi-
mum load is dangerous. The added strain on your
tires could cause them to fail. You could have a
serious collision. Do not drive a vehicle loaded to the
maximum capacity at continuous speeds above
75 mph (120 km/h).
Radial Ply Tires
WARNING!
Combining radial ply tires with other types of tires
on your vehicle will cause your vehicle to handle
poorly. The instability could cause a collision. Al-
ways use radial ply tires in sets of four (or six, in the
case of trucks with dual rear wheels). Never combine
them with other types of tires.
Cuts and punctures in radial tires are repairable only in
the tread area because of sidewall flexing. Consult your
authorized tire dealer for radial tire repairs.
418 STARTING AND OPERATING
Page 423 of 636

your original equipment tire, replace (or repair) the
original equipment tire and reinstall on the vehicle at the
first opportunity.
WARNING!
Limited-use spares are for emergency use only. In-
stallation of this limited-use spare tire affects vehicle
handling. With this tire, do not drive more than the
speed listed on the limit-use spare wheel. Keep
inflated to the cold tire inflation pressure listed on
your Tire and Loading Information Placard located
on the driver ’s side door opening. Replace (or repair)
the original equipment tire at the first opportunity
and reinstall it on your vehicle. Failure to do so could
result in loss of vehicle control.
Tire Spinning
When stuck in mud, sand, snow, or ice conditions, do not
spin your vehicle’s wheels faster than 30 mph (48 km/h)
or for longer than 30 seconds continuously without
stopping when you are stuck.
Refer to “Freeing A Stuck Vehicle” in “What To Do In
Emergencies” for further information.
WARNING!
Fast spinning tires can be dangerous. Forces gener-
ated by excessive wheel speeds may cause tire dam-
age or failure. A tire could explode and injure some-
one. Do not spin your vehicle’s wheels faster than
30 mph (48 km/h) or for more than 30 seconds
continuously when you are stuck, and do not let
anyone near a spinning wheel, no matter what the
speed.
5
STARTING AND OPERATING 421
Page 424 of 636
Tread Wear Indicators
Tread wear indicators are in the original equipment tires
to help you in determining when your tires should be
replaced.These indicators are molded into the bottom of the tread
grooves. They will appear as bands when the tread depth
becomes 1/16 in (2 mm). When the tread is worn to the
tread wear indicators, the tire should be replaced.
Life Of Tire
The service life of a tire is dependent upon varying
factors including, but not limited to:
•Driving style
•Tire pressure
•Distance driven
1—WornTire
2—NewTire
422 STARTING AND OPERATING
Page 425 of 636

WARNING!
Tires and the spare tire should be replaced after six
years, regardless of the remaining tread. Failure to
follow this warning can result in sudden tire failure.
You could lose control and have a collision resulting
in serious injury or death.
Keep dismounted tires in a cool, dry place with as little
exposure to light as possible. Protect tires from contact
with oil, grease, and gasoline.
Replacement Tires
The tires on your new vehicle provide a balance of many
characteristics. They should be inspected regularly for
wear and correct cold tire inflation pressure. The manu-
facturer strongly recommends that you use tires equiva-
lent to the originals in size, quality and performance
when replacement is needed. (Refer to the paragraph on
“Tread Wear Indicators”). Refer to the “Tire and Loading Information” placard for the size designation of your tire.
The Load Index and Speed Symbol for your tire will be
found on the original equipment tire sidewall. See the
Tire Sizing Chart example found in the Tire Safety
Information section of this manual for more information
relating to the Load Index and Speed Symbol of a tire.
It is recommended to replace the two front tires or two
rear tires as a pair. Replacing just one tire can seriously
affect your vehicle’s handling. If you ever replace a
wheel, make sure that the wheel’s specifications match
those of the original wheels.
It is recommended you contact your original equipment
or an authorized tire dealer with any questions you may
have on tire specifications or capability. Failure to use
equivalent replacement tires may adversely affect the
safety, handling, and ride of your vehicle.
5
STARTING AND OPERATING 423
Page 426 of 636

WARNING!
•Do not use a tire, wheel size or rating other than
that specified for your vehicle. Some combinations
of unapproved tires and wheels may change sus-
pension dimensions and performance characteris-
tics, resulting in changes to steering, handling, and
braking of your vehicle. This can cause unpredict-
able handling and stress to steering and suspen-
sion components. You could lose control and have
a collision resulting in serious injury or death. Use
only the tire and wheel sizes with load ratings
approved for your vehicle.
•Never use a tire with a smaller load index or
capacity other than what was originally equipped
on your vehicle. Using a tire with a smaller load
index could result in tire overloading and failure.
You could lose control and have a collision.(Continued)
WARNING! (Continued)
•Failure to equip your vehicle with tires having
adequate speed capability can result in sudden tire
failure and loss of vehicle control.
CAUTION!
Replacing original tires with tires of a different size
may result in false speedometer and odometer read-
ings.
SUPPLEMENTAL TIRE PRESSURE INFORMATION
— IF EQUIPPED
A light load vehicle condition is defined as two passen-
gers [150 lbs (68 kg) each] plus 200 lbs (91 kg) of cargo.
Cold tire inflation pressures for a lightly loaded vehicle
will be found on the face of the driver’s door.
424 STARTING AND OPERATING
Page 429 of 636

CAUTION!
Do not use tire chains on the front wheels of any
model except for 3500 DRW (Dual Rear Wheel)
trucks equipped with LT235/80R17E tires. There may
not be adequate clearance for the chains and you are
risking structural or body damage to your vehicle. Do
not use tire chains on the rear wheels of 1500 model
trucks equipped with LT275/70R17, P275/60R20, or
285/45R22 tires. There may not be adequate clearance
for the chains and you are risking structural or body
damage to your vehicle.
SNOW TIRES
Some areas of the country require the use of snow tires
during the winter. All season tires can be identified by the
M+S designation on the tire sidewall.If you need snow tires, select tires equivalent in size and
type to the original equipment tires. Use snow tires only
in sets of four; failure to do so may adversely affect the
safety and handling of your vehicle.
Snow tires generally have lower speed ratings than what
was originally equipped with your vehicle and should
not be operated at sustained speeds over 75 mph
(120 km/h). For speeds above 75 mph (120 km/h) refer to
original equipment or an authorized tire dealer for
recommended safe operating speeds, loading and cold
tire inflation pressures.
While studded tires improve performance on ice, skid
and traction capability on wet or dry surfaces may be
poorer than that of non-studded tires. Some states pro-
hibit studded tires; therefore, local laws should be
checked before using these tire types.
5
STARTING AND OPERATING 427
Page 432 of 636

CAUTION!
3500 Dual Rear Tires have only one approved direc-
tion of rotation. This is to accommodate the asym-
metrical design (tread pattern) of the On/Off-Road
tire and the use of Outline White Letter (OWL) tires.
•When replacing a flat, the spare tire may have to
be remounted on the rim, or installed at a different
location, to maintain the correct placement of the
tire on the wheel relative to the tire/wheel position
on the truck. For example, if the spare is used to
replace an outer rear tire it will have to be re-
mounted on the rim so that the wheel is dished
inward. That way the tread design of asymmetrical
tires and the white writing of the OWL tires will
maintain proper position.
TIRE PRESSURE MONITOR SYSTEM (TPMS)
The Tire Pressure Monitor System (TPMS) will warn the
driver of a low tire pressure based on the vehicle recom-
mended cold placard pressure.
The tire pressure will vary with temperature by about
1 psi (6.9 kPa) for every 12°F (6.5°C). This means that
when the outside temperature decreases, the tire pressure
will decrease. Tire pressure should always be set based
on cold inflation tire pressure. This is defined as the tire
pressure after the vehicle has not been driven for at least
three hours, or driven less than 1 mile (1.6 km) after a
three hour period. The cold tire inflation pressure must
not exceed the maximum inflation pressure molded into
the tire sidewall. Refer to “Tires – General Information”
in “Starting and Operating” for information on how to
properly inflate the vehicle’s tires. The tire pressure will
also increase as the vehicle is driven - this is normal and
there should be no adjustment for this increased pres-
sure.
430 STARTING AND OPERATING
Page 433 of 636

The TPMS will warn the driver of a low tire pressure if
the tire pressure falls below the low-pressure warning
limit for any reason, including low temperature effects
and natural pressure loss through the tire.
The TPMS will continue to warn the driver of low tire
pressure as long as the condition exists, and will not turn
off until the tire pressure is at or above the recommended
cold placard pressure. Once the low tire pressure warn-
ing (Tire Pressure Monitoring [TPM] Telltale Light) illu-
minates, you must increase the tire pressure to the
recommended cold placard pressure in order for the TPM
Telltale Light to turn off. The system will automatically
update and the TPM Telltale Light will turn off once the
system receives the updated tire pressures. The vehicle
may need to be driven for up to 20 minutes above 15 mph
(24 km/h) in order for the TPMS to receive this informa-
tion.For example, your vehicle may have a recommended
cold (parked for more than three hours) placard pressure
of 30 psi (207 kPa). If the ambient temperature is 68°F
(20°C) and the measured tire pressure is 27 psi (186 kPa),
a temperature drop to 20°F (-7°C) will decrease the tire
pressure to approximately 23 psi (158 kPa). This tire
pressure is sufficiently low enough to turn ON the TPM
Telltale Light. Driving the vehicle may cause the tire
pressure to rise to approximately 27 psi (186 kPa), but the
TPM Telltale Light will still be ON. In this situation, the
TPM Telltale Light will turn OFF only after the tires are
inflated to the vehicle’s recommended cold placard pres-
sure value.
5
STARTING AND OPERATING 431