wheel size RAM 1500 2021 User Guide

328SAFETY
pressure should always be set based on cold
inflation tire pressure. This is defined as the tire
pressure after the vehicle has not been driven
for at least three hours, or driven less than
1 mile (1.6 km) after a three hour period. The
cold tire inflation pressure must not exceed the
maximum inflation pressure molded into the
tire sidewall. The tire pressure will also increase
as the vehicle is driven — this is normal and
there should be no adjustment for this
increased pressure.
See Úpage 443 on how to properly inflate the
vehicle’s tires.
The TPMS will warn the driver of a low tire
pressure if the tire pressure falls below the
low-pressure warning limit for any reason,
including low temperature effects and natural
pressure loss through the tire Ú page 482.
The TPMS 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 the recommended cold placard
pressure. Once the low TPMS Warning Light
illuminates, increase the tire pressure to the
recommended cold placard pressure in order
for the TPMS Warning Light to turn off. The
system will automatically update and the TPMS Warning Light will turn off once the system
receives the updated tire pressures. The vehicle
may need to be driven for up to 20 minutes
above 15 mph (24 km/h) in order for the TPMS
to receive this information.
NOTE:
When filling warm tires, the tire pressure may
need to be increased up to an additional 4 psi
(28 kPa) above the recommended cold placard
pressure in order to turn the TPMS Warning
Light off.
For example, your vehicle may have a
recommended cold (parked for more than three
hours) placard pressure of 30 psi (207 kPa). If
the ambient temperature is 68°F (20°C) and
the measured tire pressure is 27 psi (186 kPa),
a temperature drop to 20°F (-7°C) will
decrease the tire pressure to approximately
23 psi (158 kPa). This tire pressure is
sufficiently low enough to turn on the TPMS
Warning Light. Driving the vehicle may cause
the tire pressure to rise to approximately 27 psi
(186 kPa), but the TPMS Warning Light will still
be on. In this situation, the TPMS Warning Light
will turn off only after the tires are inflated to the
vehicle’s recommended cold placard pressure
value.CAUTION!
The TPMS has been optimized for the orig -
inal equipment tires and wheels. TPMS
pressures and warning have been estab -
lished for the tire size equipped on your
vehicle. Undesirable system operation or
sensor damage may result when using
replacement equipment that is not of the
same size, type, and/or style. Aftermarket
wheels can cause sensor damage.
Using aftermarket tire sealants may cause
the Tire Pressure Monitoring System
(TPMS) sensor to become inoperable. After
using an aftermarket tire sealant it is
recommended that you take your vehicle to
an authorized dealership to have your
sensor function checked.
After inspecting or adjusting the tire pres -
sure always reinstall the valve stem cap.
This will prevent moisture and dirt from
entering the valve stem, which could
damage the TPMS sensor.

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330SAFETY
Should this occur, you should stop as soon as
possible and inflate the tires with a low pressure
condition (those in a different color in the
instrument cluster graphic) to the vehicle’s
recommended cold placard pressure inflation
value as shown in the "Inflate to XX" message.
Once the system receives the updated tire
pressures, the system will automatically
update, the graphic display in the instrument
cluster will return to its original color, and the
Tire Pressure Monitoring System Warning Light
will turn off. The vehicle may need to be driven
for up to 20 minutes above 15 mph (24 km/h)
in order for the TPMS to receive this
information.
NOTE:
When filling warm tires, the tire pressure may
need to be increased up to an additional 4 psi
(28 kPa) above the recommended cold placard
pressure in order to turn the Tire Pressure Moni -
toring System Warning Light off.
Service TPMS Warning
If a system fault is detected, the Tire Pressure
Monitoring System (TPMS) Warning Light will
flash on and off for 75 seconds and then remain
on solid. The system fault will also sound a
chime. In addition, the instrument cluster will display a "SERVICE TPMS SYSTEM" message for
a minimum of five seconds and then display
dashes (--) in place of the pressure value to
indicate which sensor is not being received.
If the ignition switch is cycled, this sequence will
repeat, providing the system fault still exists. If
the system fault no longer exists, the Tire
Pressure Monitoring System Warning Light will
no longer flash, and the "SERVICE TPMS
SYSTEM" message will no longer display, and a
pressure value will display in place of the
dashes. A system fault can occur due to any of
the following:
Signal interference due to electronic devices
or driving next to facilities emitting the same
radio frequencies as the Tire Pressure Moni
-
toring System sensors
Installing aftermarket window tinting that
contains materials that may block radio wave
signals
Accumulation of snow or ice around the
wheels or wheel housings
Using tire chains on the vehicle
Using wheels/tires not equipped with TPMS
sensors A system fault may occur due to an incorrect
TPMS sensor location condition. When a system
fault occurs due to an incorrect TPMS sensor
location, the Tire Pressure Monitoring System
(TPMS) Warning Light will flash on and off for
75 seconds and then remain on solid. The
system fault will also sound a chime. In
addition, the instrument cluster will display a
Tire Pressure Temporarily Unavailable message
in place of the tire pressure display screen. If
the ignition switch is cycled, this sequence will
repeat, providing the system fault still exists. If
the system fault no longer exists, the “Tire
Pressure Monitoring System Warning Light” will
no longer flash and the tire pressure display
screen will be displayed showing the tire
pressure values the correct locations.
Vehicles With Non-Matching Full Size Spare Or
Compact Spare
The non-matching full size spare or compact
spare tire does not have a TPMS sensor.
Therefore, the TPMS will not monitor the
pressure in the non-matching full size spare
or compact spare tire.
If you install the non-matching full size spare
or compact spare tire in place of a road tire
that has a pressure below the low-pressure

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SAFETY345
On the other hand, depending on the type and
location of impact, 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 collisions, and also are needed to help keep
you in position, away from an inflating air bag.
When the Occupant Restraint Controller (ORC)
detects a collision requiring the front air bags, it
signals the inflator units. A large quantity of
non-toxic gas is generated to inflate the front air
bags.
The steering wheel hub trim cover and the
upper passenger side of the instrument panel
separate and fold out of the way as the air bags
inflate to their full size. The front air bags fully
inflate in less time than it takes to blink your
eyes. The front air bags then quickly deflate
while helping to restrain the driver and front
passenger.Occupant Classification System (OCS) —
Front Passenger Seat
The OCS is part of a Federally regulated safety
system for this vehicle. It is designed to provide
Passenger Advanced Front Air Bag output
appropriate to the occupant’s seated weight, as
determined by the OCS.
The Occupant Classification System (OCS)
consists of the following:
Occupant Restraint Controller (ORC)
Occupant Classification Module (OCM) and
Sensor located in the front passenger seat
Air Bag Warning Light
Occupant Classification Module (OCM) And
Sensor
The Occupant Classification Module (OCM) is
located underneath the front passenger seat.
The Sensor is located beneath the passenger
seat cushion foam. Any weight on the seat will
be sensed by the Sensor. The OCM uses input
from the Sensor to determine the front
passenger’s most probable classification. The
OCM communicates this information to the ORC. The ORC may reduce the inflation rate of
the Passenger Advanced Front Air Bag
deployment based on occupant classification.
In order for the OCS to operate as designed, it is
important for the front passenger to be seated
properly and properly wearing the seat belt.
The OCS will NOT prevent deployment of the
Passenger Advanced Front Air Bag. The OCS
may reduce the inflation rate of the Passenger
Advanced Front Air Bag if the OCS estimates
that:
The front passenger seat is unoccupied or
has very light objects on it; or
The front passenger seat is occupied by a
small passenger, including a child; or
The front passenger seat is occupied by a
rear-facing child restraint; or
The front passenger is not properly seated or
his or her weight is taken off of the seat for a
period of time.
6

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SERVICING AND MAINTENANCE453
(Continued)
NOTE:
Wheel Valve Stem must be replaced as well
when installing new tires due to wear and tear
in existing tires.
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. FCA strongly
recommends that you use tires equivalent to
the originals in size, quality and performance
when replacement is needed Ú page 452. 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.
For more information relating to the Load Index
and Speed Symbol of a tire Ú
page 444.
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 an 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!
Tires and the spare tire should be replaced after
six years, regardless of the remaining tread.
Failure to follow this warning can result in sud -
den tire failure. You could lose control and have
a collision resulting in serious injury or death.
WARNING!
Do not use a tire, wheel size, load rating, or
speed rating other than that specified for
your vehicle. Some combinations of unap -
proved tires and wheels may change
suspension dimensions and performance
characteristics, resulting in changes to
steering, 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.
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.
8

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SERVICING AND MAINTENANCE455
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.
For restrictions when towing with a spare tire
designated for temporary emergency use
Úpage 222.
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
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.
Collapsible Spare Tire — If Equipped
The collapsible spare is for temporary
emergency use only. You can identify if your
vehicle is equipped with a collapsible 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.
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.
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.
8

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456SERVICING AND MAINTENANCE
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.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.
WHEEL AND WHEEL TRIM CARE
All wheels and wheel trim, especially aluminum
and chrome plated wheels, should be cleaned
regularly using mild (neutral Ph) soap and water
to maintain their luster and to prevent
corrosion. Wash wheels with the same soap
solution recommended for the body of the
vehicle and remember to always wash when the
surfaces are not hot to the touch.
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.
WARNING!
Limited use spares are for emergency use
only. Installation 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.

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458SERVICING AND MAINTENANCE
SNOW TRACTION DEVICES
Use of traction devices require sufficient
tire-to-body clearance. Due to limited clearance,
the following snow traction devices are
recommended. Follow these recommendations
to guard against damage:
Snow traction device must be of proper size
for the tire, as recommended by the snow
traction device manufacturer.
No other tire sizes are recommended for use
with the snow traction device.
Please follow the table below for the recom -
mended tire size, axle and snow traction
device:
4x2 (2WD)
Trim Level Axle
Tire/Wheel Size Snow Traction Device
(maximum projection beyond tire profile or equivalent)
HFE
Tradesman
Bighorn Lonestar Laramie Rear
275/65R18
275/55R20 S Class
Longhorn Sport
Limited Rear
275/55R20 S Class
REBEL Not Chainable

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SERVICING AND MAINTENANCE459
(Continued)
(Continued)
4x4 (4WD)
Trim Level Axle
Tire/Wheel Size Snow Traction Device
(maximum projection beyond tire profile or equivalent)
Tradesman
Bighorn Lonestar Laramie Rear
275/65R18
275/55/R20 S Class
Longhorn Sport
Limited Rear
275/55R20 S Class
REBEL Not Chainable
WARNING!
Using tires of different size and type (M+S,
Snow) between front and rear axles can
cause unpredictable handling. You could lose
control and have a collision.
CAUTION!
To avoid damage to your vehicle or tires,
observe the following precautions:
Because of restricted traction device clear-
ance between tires and other suspension
components, it is important that only trac-
tion devices in good condition are used.
Broken devices can cause serious damage.
Stop the vehicle immediately if noise
occurs that could indicate device breakage.
Remove the damaged parts of the device
before further use.
Install device as tightly as possible and
then retighten after driving about ½ mile
(0.8 km). Autosock traction devices do not
require retightening.
Do not exceed 30 mph (48 km/h).
Drive cautiously and avoid severe turns and
large bumps, especially with a loaded
vehicle.
Do not drive for a prolonged period on dry
pavement.
CAUTION! (Continued)
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467
TECHNICAL SPECIFICATIONS
VEHICLE IDENTIFICATION NUMBER
The Vehicle Identification Number (VIN) is found
on the left front corner of the instrument panel,
visible through the windshield.
Vehicle Identification Number

NOTE:
It is illegal to remove or alter the VIN.
BRAKE SYSTEM
If power assist is lost for any reason (for
example, repeated brake applications with the
engine off), the brakes will still function.
However, you will experience a substantial
increase in braking effort to stop the vehicle.
If either the front or rear hydraulic system loses
normal braking capability, the remaining
system will still function with some loss of
overall braking effectiveness. This will be
evident by increased pedal travel during
application, greater pedal force required to slow
or stop, and the “Brake Warning Light” and the
“ABS Warning Light” will activate during brake
use.
WHEEL AND TIRE TORQUE SPECIFICATIONS
Proper lug nut/bolt torque is very important to
ensure that the wheel is properly mounted to
the vehicle. Any time a wheel has been removed
and reinstalled on the vehicle, the lug nuts/
bolts should be torqued using a properly
calibrated torque wrench using a six sided (hex)
deep wall socket.
TORQUE SPECIFICATIONS
**Use only authorized dealer recommended lug nuts/
bolts and clean or remove any dirt or oil before tightening.
Lug Nut/ Bolt
Torque Lug Nut/
Bolt Type **Lug
Nut/Bolt Size Lug Nut/
Bolt
Socket Size
130
Ft-Lbs
(176 N·m) Cone
M14 x
1.50 22 mm
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491
Tires
................................... 371, 449, 455, 460Aging (Life Of Tires)................................... 452Air Pressure............................................... 449Chains....................................................... 458Compact Spare......................................... 455Dual........................................................... 467General Information........................ 449, 455High Speed................................................ 451Inflation Pressure...................................... 450Life Of Tires............................................... 452Load Capacity............................................ 447Pressure Monitoring System (TPMS)........................................ 131, 327Quality Grading.......................................... 460Radial........................................................ 451Replacement............................................. 453Rotation.................................................... 460Safety.............................................. 443, 449Sizes.......................................................... 444Snow Tires................................................. 454Spare Tires...................................... 455, 456Spinning.................................................... 452Trailer Towing............................................ 222Tread Wear Indicators............................... 452Wheel Nut Torque..................................... 467To Open Hood.................................................. 84Tongue Weight/Trailer Weight....................... 219Tonneau Cover....................................... 97, 462Tonneau Cover Cleaning................................ 462
Towing................................................. 214, 392Disabled Vehicle....................................... 392Guide........................................................ 218Recreational............................................. 230Weight...................................................... 218Towing Behind A Motorhome........................ 230Traction......................................................... 234Traction Control............................................ 318Trailer Reverse Steering Control................... 219Trailer Sway Control (TSC)............................. 318Trailer Towing............................................... 214Hitches..................................................... 218Minimum Requirements........................... 221Mirrors......................................................... 48Tips........................................................... 227Trailer And Tongue Weight........................ 219Wiring....................................................... 225Trailer Towing Guide..................................... 218Trailer Weight................................................ 218Transfer Case............................................... 427Electronically Shifted....................... 161, 163Fluid......................................................... 478Transmission................................................ 156Automatic........................................ 156, 426Fluid......................................................... 478Maintenance............................................ 426Shifting..................................................... 154Transporting Pets.......................................... 369Tread Wear Indicators.................................. 452Turn Signals......................... 55, 136, 439, 441
U
UconnectPhone Call Features
................................. 276Things You Should Know About Your Uconnect Phone................................... 279Uconnect App................................................ 284Uconnect Phone................................... 272, 273Answer Or Ignore An Incoming Call — Call Currently In Progress..................... 278Answer Or Ignore An Incoming Call — No Call Currently In Progress................ 277Bluetooth Communication Link................ 281Call Continuation...................................... 279Call Controls............................................. 277Call Termination....................................... 279Cancel Command..................................... 273Connecting To A Particular Mobile Phone Or Audio Device After Pairing................ 275Help Command......................................... 273Join Calls.................................................. 279Making A Phone Or Audio Device AFavorite................................................ 275Making A Second Call While Current Call Is In Progress........................................ 278Managing Your Favorites.......................... 276Natural Speech......................................... 272Operation.................................................. 272Overview................................................... 27111

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