2008 DODGE RAM 2500 DIESEL Owners Manual

SNOW TIRES
Snow tires should be of the same size and type construc-
tion as the front tires. Consult the manufacturer of the
snow tire to determine any maximum vehicle speed
requirement associated with the tire. These tires should
always be operated at the vehicle maximum capacity
inflation pressures under any load condition.
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.
TIRE ROTATION RECOMMENDATIONS
Tires on the front and rear axles of vehicles operate at
different loads and perform different steering, driving,
and braking functions. For these reasons, they wear at
unequal rates and develop irregular wear patterns. These
effects can be reduced by timely rotation of tires. The
benefits of rotation are especially worthwhile with ag-
gressive tread designs such as those on ON/OFF Road
type tires. Rotation will increase tread life, help to main-
tain mud, snow, and wet traction levels, and contribute to
a smooth, quiet ride.
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Follow the recommended tire rotation frequency for your
type of driving found in the ªMaintenance Schedulesº
Section of this manual. More frequent rotation is permis-
sible if desired. The reasons for any rapid or unusual
wear should be corrected prior to rotation being per-
formed.NOTE:On Canadian vehicles only, if your vehicle is
equipped with All-Season type tires on the front and
ON/OFF Road type tires mounted on the rear, do not use
a front-to-back rotation pattern. Instead, rotate your tires
side-to-side at the recommended intervals.
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Dual Rear Wheels
The tires used on dual wheel assemblies should be
matched for wear to prevent overloading one tire in a set.
To check if tires are even, lay a straight edge across all
four tires. The straight edge should touch all the tires.
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.
²When 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.
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TIRE PRESSURE MONITOR SYSTEM (TPMS) Ð IF
EQUIPPED
The Tire Pressure Monitoring System (TPMS) will warn
the driver of a low tire pressure based on the vehicle
recommended cold tire inflation placard pressure. The
placard pressure is defined on the Tire and Loading
Information label. The Tire and Loading Information
label is located on the drivers side B-pillar. Vehicles
equipped to be operated in either the ªmax load inflation
pressureº condition described on the Tire and Loading
Information label or the alternative ªlight load inflation
pressureº condition described on the Supplemental Tire
Pressure Information label, may also be equipped with a
reset switch to choose the appropriate TPMS low pres-
sure warning threshold levels based upon the vehicle
load condition. The Supplemental Tire Pressure Informa-
tion label is located on the rear face of the driver door.
Operation of the ªLight Loadº reset switch is described
later in this manual section.The tire pressure will vary with temperature by approxi-
mately 1 psi (6.9 kPa) for every 12ÉF (6.5ÉC). 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 a vehicle has not been driven for
more than 3 hours, or driven less than 1 mile after a 3
hour period. For information on how to properly inflate
the vehicle's tires, refer to ºTire Pressureº under ªTires ±
General Informationº in this section. The tire pressure
will also increase as the vehicle is driven - this is normal
and there should be no adjustment for this increased
pressure.
The TPM System will warn the driver of a low tire
pressure if the tire pressure falls below the low pressure
warning threshold for any reason, including low tem-
perature effects, or natural pressure loss through the tire.
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The TPM System 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 recom-
mended cold placard pressure. Once the low tire pressure
warning has been illuminated, the tire pressure must be
increased to the recommended cold placard pressure in
order for the TPMS warning lamp to be turned off. The
system will automatically update and the TPMS warning
lamp will extinguish once the updated tire pressures
have been received. The vehicle may need to be driven
for up to 10 minutes above 15 mph (25 km/h) to receive
this information.
As an example, assume your vehicle has a recommended
cold tire inflation placard pressure (parked for more than
3 hours) of 35 psi (241 kPa). If the ambient temperature is
68ÉF (20ÉC) and the measured tire pressure is 30 psi (207
kPa), a temperature drop to 20ÉF (-7ÉC) will decrease the
tire pressure to approximately 26 psi (179 kPa). This tire
pressure is sufficiently low enough to turn ON the TirePressure Monitoring lamp. Driving the vehicle may cause
the tire pressure to rise to approximately 30 psi (207 kPa),
but the Tire Pressure Monitoring lamp will still be ON. In
this situation, the Tire Pressure Monitoring lamp will
turn OFF only after the tires have been inflated to the
vehicle's recommended cold tire placard pressure value.
CAUTION!
The TPMS has been optimized for the original
equipment tires and wheels. TPMS pressures have
been established for the tire size equipped on your
vehicle. Undesirable system operation or sensor
damage may result when using replacement equip-
ment that is not of the same size, type, and/or style.
After-market wheels can cause sensor damage. Do
not use aftermarket tire sealants or balance beads if
your vehicle is equipped with a TPMS, as damage to
the sensors may result.
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CAUTION!
After inspecting or adjusting the tire pressure always
reinstall the valve stem cap. This will prevent mois-
ture and dirt from entering the valve stem, which
could damage the Tire Pressure Monitoring Sensor.
NOTE:
²The TPMS is not intended to replace normal tire care
and maintenance, nor to provide warning of a tire
failure or condition.
²The TPMS should not be used as a tire pressure gauge
while adjusting your tire pressure.
²Driving on a significantly under-inflated tire causes
the tire to overheat and can lead to tire failure.
Under-inflation also reduces fuel efficiency and tire
tread life, and may affect the vehicle's handling and
stopping ability.
²The TPMS is not a substitute for proper tire mainte-
nance, and it is the driver 's responsibility to maintain
correct tire pressure, even if under-inflation has not
reached the level to trigger illumination of the ªTire
Pressure Monitoring Telltale Light.º
²Seasonal temperature changes will affect tire pressure,
and the TPM system will monitor the actual tire
pressure in the tire.
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Tire Pressure Monitor System (TPMS) ªLight
Loadº Reset Switch Description ± If Equipped
WARNING!
Never operate your vehicle with the TPMS and tire
pressures set to the Light Load Inflation Pressure
settings if carrying more than two occupants (150 lbs
each) plus 200 pounds of cargo. The vehicle ªLight
Load Definitionº is found in the Supplemental Tire
Pressure Information Label which is located on the
rear face of the driver door. Failure to do so may
cause you to lose control resulting in an accident,
causing serious or fatal injury.The TPMS ªLight Loadº reset switch will allow the driver
to switch between the max load inflation pressure (cold)
low pressure warning threshold and the light load infla-
tion pressure (cold) low pressure warning threshold
depending on the vehicle's load condition. The Tire and
Loading Information label defines the recommended
front and rear cold tire inflation pressures for the vehicle
when operating in the Max Load condition. A Supple-
mental Tire Pressure Information label is also available
defining Light Load tire inflation pressures when oper-
ating in the Light Load condition. When the ªLight Loadº
reset switch LED is ON, the TPMS is using the light load
inflation pressure (cold) low inflation warning thresh-
olds.
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ªLight Loadº Reset Switch Operation ± If
Equipped
²
This vehicle may have different recommended tire
pressure values between the front and rear tires as
shown in both the Tire Loading Information Label and
the Supplemental Tire Pressure Information Label. It is
also equipped to be driven with tire pressures appro-
priate to either a Light Load condition or the vehicle
Max Load condition.
²The ªLight Loadº reset switch will allow the driver to
change between the max load inflation pressure (cold)
low pressure warning threshold and the light load
inflation pressure (cold) low pressure warning thresh-
old depending on the vehicle's load condition. Refer to
the ªSupplemental Tire Pressure Informationº label for
the vehicle's Light Load inflation pressures and ªTire
and Loading Informationº label for the vehicle's Max
Load inflation pressures.
Light Load Reset Switch
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