2018 Ram 2500 wheel size

When operating your vehicle in 4WD LOW, the engine
speed is approximately three times that of the 2WD, 4WD
AUTO 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 four-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
drivetrain.
Because four-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 or killed if you leave the
vehicle unattended with the transfer case in the NEU-
TRAL position without first fully engaging the park-
ing brake. The transfer case NEUTRAL position disen-
gages both the front and rear drive shafts from the
powertrain and will allow the vehicle to roll, even if
the transmission is in PARK. The parking brake
should always be applied when the driver is not in the
vehicle.
Shifting Procedure
NOTE:
•If any of the requirements to select a new transfer case
position have not been met, the transfer case will not
shift. The position indicator light for the previous posi-
tion will remain ON and the newly selected position
indicator light will continue to flash until all the require-
ments for the selected position have been met. To retry a
shift: return the control switch back to the original
position, make certain all shift requirements have been
met, wait five seconds and try the shift again.
• If all the requirements to select a new transfer case
position have been met, the current position indicator
light will turn OFF, the selected position indicator light
will flash until the transfer case completes the shift.
When the shift is complete, the position indicator light
for the selected position will stop flashing and
remain ON.
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STARTING AND OPERATING 335

If One Or More Of The Following Shift Conditions Are
Not Met:
1.
The indicator light for the current position will remain ON.
2. The newly selected position indicator light will continueto flash.
3. The transfer case will notshift.
NOTE: Before retrying a selection, make certain that all the
necessary requirements for selecting a new transfer case
position have been met. To retry the selection, push the
current position, wait five seconds, and retry selection. To
find the shift requirements, refer to the Shifting Procedure
for your transfer case, located in this section.
The “SVC 4WD Warning Light” monitors the electronic
shift four-wheel drive system. If this light remains on after
engine start up or illuminates during driving, it means that
the four-wheel drive system is not functioning properly
and that service is required.
WARNING!
Always engage the parking brake when powering
down the vehicle if the “SVC 4WD Warning Light” is
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WARNING! (Continued)
illuminated. Not engaging the parking brake may
allow the vehicle to roll which may cause personal
injury or death.
NOTE: Do not attempt to make a shift while only the front
or rear wheels are spinning. This could cause damage to
driveline components.
When operating your vehicle in 4WD LOW, the engine
speed is approximately three times that of the 2WD, 4WD
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 four-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
drivetrain.
Because four-wheel drive provides improved traction,
there is a tendency to exceed safe turning and stopping
speeds. Do not go faster than road conditions permit.
338 STARTING AND OPERATING

Proper operation of four-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
drivetrain.
Because four-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 or killed if you leave
the vehicle unattended with the transfer case in the
NEUTRAL (N) position without first fully engaging
the parking brake. The transfer case NEUTRAL (N)
position disengages both the front and rear drive
shaft from the powertrain, and will allow the vehicle
to roll, even if the automatic transmission is in PARK
(or manual transmission is in gear). The parking
brake should always be applied when the driver is
not in the vehicle.
• The transmission may not engage PARK if the ve-
hicle is moving. Always bring the vehicle to a
complete stop before shifting to PARK, and verify
that the transmission gear position indicator solidly
(Continued)
WARNING! (Continued)
indicates PARK (P) without blinking. Ensure that the
vehicle is completely stopped, and the PARK posi-
tion is properly indicated, before exiting the vehicle.
Shifting Procedure
NOTE:
•If any of the requirements to select a new transfer case
position have not been met, the transfer case will not
shift. The position indicator light for the previous posi-
tion will remain ON and the newly selected position
indicator light will continue to flash until all the require-
ments for the selected position have been met.
• If all the requirements to select a new transfer case
position have been met, the current position indicator
light will turn OFF, the selected position indicator light
will flash until the transfer case completes the shift.
When the shift is complete, the position indicator light
for the selected position will stop flashing and
remain ON.
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STARTING AND OPERATING 343

Gross Axle Weight Rating (GAWR)
The GAWR is the maximum permissible load on the front
and rear axles. The load must be distributed in the cargo
area so that the GAWR of each axle is not exceeded.
Each axle GAWR is determined by the components in the
system with the lowest load carrying capacity (axle,
springs, tires or wheels). Heavier axles or suspension
components sometimes specified by purchasers for in-
creased durability does not necessarily increase the vehi-
cle’s GVWR.
Tire Size
The tire size on the Vehicle Certification Label represents
the actual tire size on your vehicle. Replacement tires must
be equal to the load capacity of this tire size.
Rim Size
This is the rim size that is appropriate for the tire size
listed.
Inflation Pressure
This is the cold tire inflation pressure for your vehicle for
all loading conditions up to full GAWR.
Curb Weight
The curb weight of a vehicle is defined as the total weight
of the vehicle with all fluids, including vehicle fuel, at full
capacity conditions, and with no occupants or cargo loaded
into the vehicle. The front and rear curb weight values are
determined by weighing your vehicle on a commercial
scale before any occupants or cargo are added.
Loading
The actual total weight and the weight of the front and rear
of your vehicle at the ground can best be determined by
weighing it when it is loaded and ready for operation.
The entire vehicle should first be weighed on a commercial
scale to insure that the GVWR has not been exceeded. The
weight on the front and rear of the vehicle should then be
determined separately to be sure that the load is properly
distributed over the front and rear axle. Weighing the
vehicle may show that the GAWR of either the front or rear
axles has been exceeded but the total load is within the
specified GVWR. If so, weight must be shifted from front to
rear or rear to front as appropriate until the specified
weight limitations are met. Store the heavier items down
low and be sure that the weight is distributed equally. Stow
all loose items securely before driving.6
STARTING AND OPERATING 415

WARNING!(Continued)
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 pressures. The manu-
facturer strongly recommends that you use tires equivalent
to the originals in size, quality and performance when
replacement is needed. Refer to the paragraph on “Tread
Wear Indicators” in this section. Refer to the Tire and
Loading Information placard or the Vehicle Certification
Label 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 authorized tire dealer
or original equipment 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.
WARNING!
•
Do not use a tire, wheel size, load rating, or speed
rating other than that specified for your vehicle.
Some combinations of unapproved tires and wheels
may change suspension dimensions and perfor-
mance characteristics, resulting in changes to steer-
ing, handling, and braking of your vehicle. This can
cause unpredictable handling and stress to steering
and suspension 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.
(Continued)
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SERVICING AND MAINTENANCE 573

Snow Tires
Some areas of the country require the use of snow tires
during the Winter. Snow tires can be identified by a
“mountain/snowflake” symbol on the tire sidewall.If you need snow tires, select tires
equivalent in size and type to the origi-
nal 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 prohibit stud-
ded tires; therefore, local laws should be checked before
using these tire types.
Spare Tires — If Equipped
NOTE: For vehicles equipped with Tire Service Kit instead
of a spare tire, please refer to “Tire Service Kit” in “In Case
Of Emergency” for further information.
CAUTION!
Because of the reduced ground clearance, do not take
your vehicle through an automatic car wash with a
compact or limited use temporary spare installed.
Damage to the vehicle may result.
Spare Tire Matching Original Equipped Tire And
Wheel — If Equipped
Your vehicle may be equipped with a spare tire and wheel
equivalent in look and function to the original equipment
tire and wheel found on the front or rear axle of your
vehicle. This spare tire may be used in the tire rotation for
your vehicle. If your vehicle has this option, refer to an
authorized tire dealer for the recommended tire rotation
pattern.
Compact Spare Tire — If Equipped
The compact spare is for temporary emergency use only.
You can identify if your vehicle is equipped with a compact
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SERVICING AND MAINTENANCE 575

spare by looking at the spare tire description on the Tire
and Loading Information Placard located on the driver ’s
side door opening or on the sidewall of the tire. Compact
spare tire descriptions begin with the letter “T” or “S”
preceding the size designation. Example: T145/80D18
103M.
T, S = Temporary Spare Tire
Since this tire has limited tread life, the original equipment
tire should be repaired (or replaced) and reinstalled on
your vehicle at the first opportunity.
Do not install a wheel cover or attempt to mount a
conventional tire on the compact spare wheel, since the
wheel is designed specifically for the compact spare tire.
Do not install more than one compact spare tire and wheel
on the vehicle at any given time.
WARNING!
Compact and collapsible spares are for temporary
emergency use only. With these spares, do not drive
more than 50 mph (80 km/h). Temporary use spares
have limited tread life. When the tread is worn to the
tread wear indicators, the temporary use spare tire
(Continued)
WARNING!(Continued)
needs to be replaced. Be sure to follow the warnings,
which apply to your spare. Failure to do so could result
in spare tire failure and loss of vehicle control.
Collapsible Spare Tire — If Equipped
The collapsible spare is for temporary emergency use only.
You can identify if your vehicle is equipped with a collaps-
ible spare by looking at the spare tire description on the
Tire and Loading Information Placard located on the
driver ’s side door opening or on the sidewall of the tire.
Collapsible spare tire description example: 165/80-17 101P.
Since this tire has limited tread life, the original equipment
tire should be repaired (or replaced) and reinstalled on
your vehicle at the first opportunity.
Inflate collapsible tire only after the wheel is properly
installed to the vehicle. Inflate the collapsible tire using the
electric air pump before lowering the vehicle.
Do not install a wheel cover or attempt to mount a
conventional tire on the collapsible spare wheel, since the
wheel is designed specifically for the collapsible spare tire.
576 SERVICING AND MAINTENANCE

WARNING!
Compact and Collapsible spares are for temporary
emergency use only. With these spares, do not drive
more than 50 mph (80 km/h). Temporary use spares
have limited tread life. When the tread is worn to the
tread wear indicators, the temporary use spare tire
needs to be replaced. Be sure to follow the warnings,
which apply to your spare. Failure to do so could result
in spare tire failure and loss of vehicle control.
Full Size Spare — If Equipped
The full size spare is for temporary emergency use only.
This tire may look like the originally equipped tire on the
front or rear axle of your vehicle, but it is not. This spare
tire may have limited tread life. When the tread is worn to
the tread wear indicators, the temporary use full size spare
tire needs to be replaced. Since it is not the same as your
original equipment tire, replace (or repair) the original
equipment tire and reinstall on the vehicle at the first
opportunity.
Limited Use Spare — If Equipped
The limited use spare tire is for temporary emergency use
only. This tire is identified by a label located on the limited
use spare wheel. This label contains the driving limitations
for this spare. This tire may look like the original equipped
tire on the front or rear axle of your vehicle, but it is not.
Installation of this limited use spare tire affects vehicle
handling. Since it is not the same as your original equip-
ment 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. Instal-
lation of this limited use spare tire affects vehicle
handling. With this tire, do not drive more than the
speed listed on the limited use spare wheel. Keep
inflated to the cold tire inflation pressures listed on
your Tire and Loading Information Placard located on
the driver ’s side B-Pillar or the rear edge of the driver ’s
side door. 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.8
SERVICING AND MAINTENANCE 577