tire size RAM 1500 2021 Owner's Manual

SERVICING AND MAINTENANCE451
cold tire inflation pressure must not exceed the
maximum inflation pressure molded into the
tire sidewall.
Check tire pressures more often if subject to a
wide range of outdoor temperatures, as tire
pressures vary with temperature changes.
Tire pressures change by approximately 1 psi
(7 kPa) per 12°F (7°C) of air temperature
change. Keep this in mind when checking tire
pressure inside a garage, especially in the
Winter.
Example: If garage temperature = 68°F (20°C)
and the outside temperature = 32°F (0°C) then
the cold tire inflation pressure should be
increased by 3 psi (21 kPa), which equals 1 psi
(7 kPa) for every 12°F (7°C) for this outside
temperature condition.
Tire pressure may increase from 2 to 6 psi
(13 to 40 kPa) during operation. DO NOT reduce
this normal pressure build up or your tire
pressure will be too low.
Tire Pressures For High Speed Operation
The manufacturer advocates driving at safe
speeds and within posted speed limits. Where
speed limits or conditions are such that the
vehicle can be driven at high speeds, maintaining correct tire inflation pressure is
very important. Increased tire pressure and
reduced vehicle loading may be required for
high-speed vehicle operation. Refer to an
authorized tire dealer or original equipment
vehicle dealer for recommended safe operating
speeds, loading and cold tire inflation
pressures.
Radial Ply Tires
Tire Repair
If your tire becomes damaged, it may be
repaired if it meets the following criteria:
The tire has not been driven on when flat
The damage is only on the tread section of
your tire (sidewall damage is not repairable)
The puncture is no greater than a ¼ of an
inch (6 mm)
Consult an authorized tire dealer for tire repairs
and additional information.
Damaged Run Flat tires, or Run Flat tires that
have experienced a loss of pressure should be
replaced immediately with another Run Flat tire
of identical size and service description (Load
Index and Speed Symbol). Replace the tire
pressure sensor as well as it is not designed to
be reused.
Run Flat Tires — If Equipped
Run Flat tires allow you the capability to drive
50 miles (80 km) at 50 mph (80 km/h) after a
rapid loss of inflation pressure. This rapid loss
of inflation is referred to as the Run Flat mode.
A Run Flat mode occurs when the tire inflation
pressure is of/or below 14 psi (96 kPa). Once a
Run Flat tire reaches the Run Flat mode it has
WARNING!
High speed driving with your vehicle under
maximum load is dangerous. The added
strain on your tires could cause them to fail.
You could have a serious collision. Do not
drive a vehicle loaded to the maximum
capacity at continuous speeds above 75 mph
(120 km/h).
WARNING!
Combining radial ply tires with other types of
tires on your vehicle will cause your vehicle to
handle poorly. The instability could cause a
collision. Always use radial ply tires in sets of
four. Never combine them with other types of
tires.
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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.
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454SERVICING AND MAINTENANCE
TIRE TYPES
All Season Tires — If Equipped
All Season tires provide traction for all seasons
(Spring, Summer, Autumn, and Winter). Traction
levels may vary between different all season
tires. All season tires can be identified by the
M+S, M&S, M/S or MS designation on the tire
sidewall. Use all season tires only in sets of four;
failure to do so may adversely affect the safety
and handling of your vehicle.
Summer Or Three Season Tires — If
Equipped
Summer tires provide traction in both wet and
dry conditions, and are not intended to be
driven in snow or on ice. If your vehicle is
equipped with Summer tires, be aware these
tires are not designed for Winter or cold driving
conditions. Install Winter tires on your vehicle
when ambient temperatures are less than 40°F
(5°C) or if roads are covered with ice or snow.
For more information, contact an authorized
dealer.
Summer tires do not contain the all season
designation or mountain/snowflake symbol on
the tire sidewall. Use Summer tires only in sets
of four; failure to do so may adversely affect the
safety and handling of your vehicle.
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
original 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
studded tires; therefore, local laws should be
checked before using these tire types.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 readings.
WARNING! (Continued)
WARNING!
Do not use Summer tires in snow/ice
conditions. You could lose vehicle control,
resulting in severe injury or death. Driving too
fast for conditions also creates the possibility
of loss of vehicle control.

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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.
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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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