2008 DODGE RAM 2500 DIESEL tire size

experience reduced performance, an elevated/rough idle
or engine stall and your vehicle may require towing. The
light will come on when the ignition is first turned on
and remain on for 15 seconds as a bulb check. If the light
does not come on during starting, have the system
checked by an authorized dealer.
22. SERV 4WD Indicator
The 4WD indicator will be illuminated whenever the
4WD mode is engaged for either the manual or electric
shift 4WD systems. The SERV 4WD indicator monitors
the electric shift 4WD system. If the SERV 4WD light
stays on or comes on during driving, it means that the
4WD system is not functioning properly and that service
is required.23. Water In Fuel Indicator
Indicates there is water detected in the fuel
filter. Refer to the Maintenance section, Drain-
ing Fuel/Water Separator Filter, for water
drain procedure.
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.)
196 UNDERSTANDING YOUR INSTRUMENT PANEL

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.
TPMS ªLight Loadº Reset Switch ± If Equipped
The TPMS ºLight Loadº reset switch allows you to
choose between Light Load vehicle conditions and Max
Load vehicle conditions tire pressures and related TPMS
warning levels. The switch is located in the instrumentpanel, below the climate control panel. For additional
information refer to ªTire Pressure Monitoring System
(TPMS) Ð If Equippedº in section 5 of this manual.
25. Transmission Oil Temperature Warning Light
(Automatic Transmissions Only)
This light indicates that there is excessive trans-
mission fluid temperature that might occur
with severe usage such as trailer towing. It may
also occur when operating the vehicle in a high
torque converter slip condition, such as 4-wheel drive
operation (e.g., snow plowing, off-road operation). If this
light comes on, stop the vehicle and run the engine at idle
or faster, with the transmission in NEUTRAL until the
light goes off.
26. Wait To Start Indicator
The Wait To Start indicator will illuminate when
the ignition is turned to the run position and the
intake manifold temperature is below 66ÉF (19ÉC).
198 UNDERSTANDING YOUR INSTRUMENT PANEL

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 light (4WD), located in the instrument
cluster, alerts the driver that the vehicle is in 4-wheel
drive and that the front and rear driveshafts are locked
together. This light illuminates when the transfer case is
shifted to either the 4H or 4L positions. There is no light
for the 2H or 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
place. Shifting while only the front or rear wheels are
spinning can cause damage to the transfer case.
Because 4-wheel drive provides improved traction, there
is a tendency to exceed safe turning and stopping speeds.
Do not go faster than road conditions permit.
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5

When operating your vehicle in 4WD LOW, the engine
speed is approximately three times that of the 2WD or
4WD LOCK 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 in tire size can cause damage to the
transfer case.
Because 4-wheel drive provides improved traction, there
is a tendency to exceed safe turning and stopping speeds.
Do not go faster than road conditions permit.WARNING!
You or others could be injured if you leave the
vehicle unattended with the transfer case in the
NEUTRAL position without first fully engaging the
parking brake. The transfer case NEUTRAL position
disengages both the front and rear driveshafts from
the powertrain and will allow the vehicle to move
regardless of the transmission position. The parking
brake should always be applied when the driver is
not in the vehicle.
For additional information on the appropriate use of each
transfer case mode position see the information below:
2WD
Rear Wheel Drive High Range - Normal street and
highway driving. Dry, hard surfaced roads.
302 STARTING AND OPERATING

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.
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.
316 STARTING AND OPERATING

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 (%).
Ð Ratio 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)
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5

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 the date code,located 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
Ð This 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 (two digits)
L9= Code representing the tire size (two digits)
ABCD= Code used by the tire manufacturer (one to four digits)
03= Number representing the week in which the tire was manufactured (two digits)
Ð03 means the 3rd week.
01= Number representing the year in which the tire was manufactured (two digits)
Ð01 means the year 2001
Ð Prior to July 2000, tire manufacturers were only required to have one number to represent the
year in which the tire was manufactured. Example: 031 could represent the 3rd week of 1981 or 1991
STARTING AND OPERATING 319
5

Tire Loading and Tire Pressure
Tire Placard Location
NOTE:The proper cold tire inflation pressure is listed
on either the face of the driver's door or the driver's side
B-Pillar.
Tire and Loading Information Placard
This placard tells you important information about the:
1) number of people that can be carried in the vehicle
2) total weight your vehicle can carry
3) tire size designed for your vehicle
4) cold tire inflation pressures for the front, rear, and
spare tires.
Tire Placard Location
Tire And Loading Information Placard
320 STARTING AND OPERATING