wheel size Ram 1500 2015 Owner's Manual

On the other hand, depending on the type and location of
impact, Advanced Front Air Bags may deploy in crashes
with little vehicle front-end damage but that produce a
severe initial deceleration.
Because air bag sensors measure vehicle deceleration
over time, vehicle speed and damage by themselves are
not good indicators of whether or not an air bag should
have deployed.
Seat belts are necessary for your protection in all colli-
sions, and also are needed to help keep you in position,
away from an inflating air bag.
When the ORC detects a collision requiring the Ad-
vanced Front Air Bags, it signals the inflator units. A large
quantity of non-toxic gas is generated to inflate the
Advanced Front Air Bags.
The steering wheel hub trim cover and the upper right
side of the instrument panel separate and fold out of the
way as the air bags inflate to their full size. The Advanced
Front Air Bags fully inflate in less time than it takes to
blink your eyes. The air bags then quickly deflate while
helping to restrain the driver and front passenger.
Knee Impact Bolsters
The Knee Impact Bolsters help protect the knees of the
driver and front passenger, and position the front occu-
pants for improved interaction with the Advanced Front
Air Bags.
WARNING!
•Do not drill, cut, or tamper with the knee impact
bolsters in any way.
•Do not mount any accessories to the knee impact
bolsters such as alarm lights, stereos, citizen band
radios, etc.
2
THINGS TO KNOW BEFORE STARTING YOUR VEHICLE 71

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.
NOTE:The TPMS telltale is also accompanied by a “Low
Tire” message in the odometer (Base Cluster), or in the
Electronic Vehicle Information Center (EVIC) screen in-
dicating “Low Tire” for EVIC enabled clusters.
17. Front Fog Light Indicator — If Equipped
This indicator will illuminate when the front
fog lights are on.
18. Electronic Vehicle Information Center (EVIC)/Driver
Information Display (DID)
The EVIC/DID features a driver-interactive display that
is located in the instrument cluster. For further informa-
tion, refer to “Electronic Vehicle Information Center
(EVIC” OR “/Driver Information Display (DID)” in
“Understanding Your Instrument Panel.”
19. Shift Lever Indicator
The Shift Lever Indicator is self-contained within the
instrument cluster. It displays the gear position of the
automatic transmission.
296 UNDERSTANDING YOUR INSTRUMENT PANEL

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 four-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 drivetrain.
NOTE:Do not attempt to make a shift while only the
front or rear wheels are spinning. 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 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.
NOTE:Delayed shifts out of four-wheel drive may be
experienced due to uneven tire wear, low or uneven tire
pressures, excessive vehicle loading, or cold tempera-
tures.
WARNING!
You or others could be injured or killed 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 drive shafts 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.
5
STARTING AND OPERATING 495

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, turn
the control knob back to the current position, wait five
seconds, and retry selection. To find the shift require-
ments, 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 function-
ing properly and that service is required.
WARNING!
Always engage the parking brake when powering down
the vehicle if the “SVC 4WD Warning Light” is illumi-
nated. Not engaging the parking brake may allow the
vehicle to roll, which may cause personal injury.
NOTE:Do not attempt to make a shift while only the
front or rear wheels are spinning, as this can cause
damage to driveline components.
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 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.
500 STARTING AND OPERATING

WARNING!
Always engage the parking brake when powering
down the vehicle if the “SVC 4WD Warning Light” is
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
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
NEUTRAL position without first fully engaging the
parking brake. The transfer case NEUTRAL position
disengages both the front and rear drive shafts 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.
5
STARTING AND OPERATING 507

after engine start up or illuminates during driving, it
means that the four-wheel drive system is not function-
ing properly and that service is required.
WARNING!
Always engage the parking brake when powering
down the vehicle if the “SVC 4WD Warning Light” is
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
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
NEUTRAL position without first fully engaging the
parking brake. The transfer case NEUTRAL position
(Continued)
512 STARTING AND OPERATING

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 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 equip-
ment 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 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.
5
STARTING AND OPERATING 615

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 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 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.
616 STARTING AND OPERATING

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 equiva-
lent to the originals in size, quality and performance
when replacement is needed. Refer to the paragraph on
“Tread Wear Indicator.” 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 ex-
ample 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.5
STARTING AND OPERATING 619

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.
620 STARTING AND OPERATING