2008 DODGE RAM 2500 POWER WAGON tire size

POWER WAGON FEATURES
Locking Front and Rear Differentials
Most 4WD trucks are equipped with open differentials
front and rear. This design is used because it allows each
wheel to turn independently helping to eliminate bind-
ing when cornering. A disadvantage of using an open
differential is when one or more wheels lose traction; all
of the power is directed to those wheels resulting in a loss
of momentum. The Power Wagon is equipped with
electronically locking front and rear differentials. These
differentials, when engaged, mechanically lock together
the axle shafts forcing the wheels to spin at an equal rate.
This allows the vehicle to maintain its momentum and
thus prevents it from becoming stuck. The locking front
and rear differentials should only be engaged during
low-speed, extreme off-road situations where one wheel
is likely to not be in contact with the ground. It is notrecommended to drive the vehicle with the differentials
locked on pavement due to the reduced ability to turn
and speed limitations.
4.56:1 Gears
This is the highest axle ratio available in a full-size
pickup. The high gearing helps to compensate for the
increased rolling mass and increase diameter of the
off-road tires. As well, there are many advantages to a
higher axle ratio in off-road applications. When driving
downhill the high gearing enables the driver to use the
engine to slow the vehicle down in a more controlled
manner. When driving up a steep grade, the ratio helps
by keeping the truck in its power band helping to
maintain upward momentum.
84 UNDERSTANDING THE FEATURES OF YOUR VEHICLE

24. Tire Pressure Monitoring Telltale Light Ð If
Equipped
Each tire, including the spare (if provided),
should be checked monthly when cold and
inflated to the inflation pressure recommended
by the vehicle manufacturer on the vehicle
placard or tire inflation pressure label. (If your vehicle
has tires of a different size than the size indicated on the
vehicle placard or tire inflation pressure label, you should
determine the proper tire inflation pressure for those
tires.)
As an added safety feature, your vehicle has been
equipped with a tire pressure monitoring system (TPMS)
that illuminates a low tire pressure telltale when one or
more of your tires are significantly under-inflated. Ac-
cordingly, when the low tire pressure telltale illuminates,
you should stop and check your tires as soon as possible,
and inflate them to the proper pressure. Driving on asignificantly under-inflated tire causes the tire to over-
heat 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.
Please note that the TPMS is not a substitute for proper
tire maintenance, 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 TPMS
low tire pressure telltale.
Your vehicle has also been equipped with a TPMS
malfunction indicator to indicate when the system is not
operating properly. The TPMS malfunction indicator is
combined with the low tire pressure telltale. When the
system detects a malfunction, the telltale will flash for
approximately one minute and then remain continuously
illuminated. This sequence will continue upon subse-
quent vehicle start-ups as long as the malfunction exists.
UNDERSTANDING YOUR INSTRUMENT PANEL 187
4

When the malfunction indicator is illuminated, the sys-
tem may not be able to detect or signal low tire pressure
as intended. TPMS malfunctions may occur for a variety
of reasons, including the installation of replacement or
alternate tires or wheels on the vehicle that prevent the
TPMS from functioning properly. Always check the
TPMS malfunction telltale after replacing one or more
tires or wheels on your vehicle to ensure that the replace-
ment or alternate tires and wheels allow the TPMS to
continue to function properly.CAUTION!
The TPMS has been optimized for the original
equipment tires and wheels. TPMS pressures and
warning have been established for the tire size
equipped on your vehicle. Undesirable system opera-
tion or sensor damage may result when using re-
placement equipment that is not of the same size,
type, and/or style. Aftermarket wheels can cause
sensor damage. Do not use tire sealant from a can, or
balance beads if your vehicle is equipped with a
TPMS, as damage to the sensors may result.
188 UNDERSTANDING YOUR INSTRUMENT PANEL

FOUR-WHEEL- DRIVE OPERATION
Manually Shifted Transfer Case Operating
Information/Precautions
The transfer case provides 4 mode positions-2(rear)-
wheel-drive high range, 4-wheel-drive high range, neu-
tral, and 4-wheel-drive low range.
This transfer case is intended to be driven in the 2-wheel-
drive position (2H) for normal street and highway con-
ditions such as dry hard surfaced roads.
When additional traction is required the transfer case 4H
and 4L positions can be used to lock the front and rear
driveshafts together and force the front and rear wheels
to rotate at the same speed. This is accomplished by
simply moving the shift lever to the desired positions.
The 4H and 4L positions are intended for loose, slippery
road surfaces only. Driving in the 4H and 4L positions on
dry hard surfaced roads may cause increased tire wear
and damage to the driveline components.The 4-wheel drive high (4LOCK) and 4±wheel drive low
(4LOW) lights, located in the instrument cluster, alert the
driver that the vehicle is either in 4-wheel drive high or
4±wheel drive low and that the front and rear driveshafts
are locked together. There are no lights for the 2H or N
(Neutral) positions.
When operating your vehicle in 4L, the engine speed is
approximately three times that of the 2H or 4H positions
at a given road speed. Take care not to overspeed the
engine and do not exceed 25 mph (40 km/h).
Proper operation of 4-wheel-drive vehicles depends on
tires of equal size, type and circumference on each wheel.
Any difference will adversely affect shifting and can
cause damage to the transfer case.
NOTE:Do not attempt to make a shift while only the
front or rear wheels are spinning. The transfer case is not
equipped with a synchronizer and therefore the front and
rear driveshaft speeds must be equal for the shift to take
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MULTI DISPLACEMENT SYSTEM (MDS) Ð 5.7L
Engine Only
This feature offers improved fuel economy by shutting
off four of the engine's eight cylinders during light load
and cruise conditions. The system is automatic with no
driver inputs or additional driving skills required.
NOTE:The MDS system may take some time to return
to full functionality after a battery disconnect.
TIRE SAFETY INFORMATION
Tire Markings
NOTE:
²P (Passenger)-Metric tire sizing is based on U.S. design
standards. P-Metric tires have the letter ªPº molded
into the sidewall preceding the size designation. Ex-
ample: P215/65R15 95H.
326 STARTING AND OPERATING

²European Metric tire sizing is based on European
design standards. Tires designed to this standard have
the tire size molded into the sidewall beginning with
the section width. The letter9P9is absent from this tire
size designation. Example: 215/65R15 96H
²LT (Light Truck)-Metric tire sizing is based on U.S.
design standards. The size designation for LT-Metric
tires is the same as for P-Metric tires except for the
letters ªLTº that are molded into the sidewall preced-
ing the size designation. Example: LT235/85R16.
²Temporary Spare tires are high-pressure compact
spares designed for temporary emergency use only.
Tires designed to this standard have the letter ªTº
molded into the sidewall preceding the size designa-
tion. Example: T145/80D18 103M.
²High Flotation tire sizing is based on U.S. design
standards and it begins with the tire diameter molded
into the sidewall. Example: 31x10.5 R15 LT.
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Tire Sizing Chart
EXAMPLE:
Size Designation:
P= Passenger car tire size based on U.S. design standards
(....blank....(= Passenger car tire based on European design standards
LT= Light Truck tire based on U.S. design standards
T= Temporary Spare tire
31= Overall Diameter in Inches (in)
215= Section Width in Millimeters (mm)
65= Aspect Ratio in Percent (%)
ÐRatio of section height to section width of tire.
10.5= Section Width in Inches (in)
R= Construction Code
Ð9R9means Radial Construction.
Ð9D9means Diagonal or Bias Construction.
15= Rim Diameter in Inches (in)
328 STARTING AND OPERATING

Tire Identification Number (TIN)
The TIN may be found on one or both sides of the tire;
however, the date code may only be on one side. Tires with
white sidewalls will have the full TIN including date codelocated on the white sidewall side of the tire. Look for the
TIN on the outboard side of black sidewall tires as mounted
on the vehicle. If the TIN is not found on the outboard side
then you will find it on the inboard side of the tire.
EXAMPLE:
DOT MA L9 ABCD 0301
DOT= Department of Transportation
ÐThis symbol certifies that the tire is in compliance with the U.S. Department of Transportation tire
safety standards, and is approved for highway use.
MA= Code representing the tire manufacturing location. (2 digits)
L9= Code representing the tire size. (2 digits)
ABCD= Code used by tire manufacturer. (1 to 4 digits)
03= Number representing the week in which the tire was manufactured. (2 digits)
Ð03 means the 3rd week.
01= Number representing the year in which the tire was manufactured. (2 digits)
Ð01 means the year 2001.
ÐPrior to July 2000, tire manufacturers were only required to have 1 number to represent the year in
which the tire was manufactured. Example: 031 could represent the 3rd week of 1981 or 1991.
330 STARTING AND OPERATING