RAM 1500 2021 Owners Manual
Page 451 of 496
SERVICING AND MAINTENANCE449
TIRES — GENERAL INFORMATION  
Tire Pressure 
Proper tire inflation pressure is essential to the 
safe and satisfactory operation of your vehicle.  Four primary areas are affected by improper tire 
pressure:Safety
Fuel Economy
Tread Wear
Ride Comfort and Vehicle Stability
WARNING!
Overloading of your tires is dangerous. 
Overloading can cause tire failure, affect 
vehicle handling, and increase your stopping 
distance. Use tires of the recommended load 
capacity for your vehicle. Never overload 
them.
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450SERVICING AND MAINTENANCE  
Safety Both underinflation and overinflation affect the 
stability of the vehicle and can produce a feeling 
of sluggish response or over responsiveness in 
the steering.
NOTE:
Unequal tire pressures from side to side may 
cause erratic and unpredictable steering 
response.
Unequal tire pressure from side to side may 
cause the vehicle to drift left or right.
Fuel Economy
Underinflated tires will increase tire rolling 
resistance resulting in higher fuel consumption.
Tread Wear
Improper cold tire inflation pressures can cause 
abnormal wear patterns and reduced tread life, 
resulting in the need for earlier tire 
replacement.
Ride Comfort And Vehicle Stability
Proper tire inflation contributes to a 
comfortable ride. Overinflation produces a 
jarring and uncomfortable ride.
Tire Inflation Pressures 
The proper cold tire inflation pressure is listed 
on the driver's side B-Pillar or rear edge of the 
driver's side door.
At least once a month:
Check and adjust tire pressure with a good 
quality pocket-type pressure gauge. Do not 
make a visual judgement when determining 
proper inflation. Tires may look properly 
inflated even when they are underinflated.
Inspect tires for signs of tire wear or visible 
damage.
Inflation pressures specified on the placard are 
always “cold tire inflation pressure”. Cold tire 
inflation pressure 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 sitting for a minimum of three hours. The 
WARNING!
Improperly inflated tires are dangerous and 
can cause collisions.
Underinflation increases tire flexing and 
can result in overheating and tire failure.
Overinflation reduces a tire's ability to 
cushion shock. Objects on the road and 
chuckholes can cause damage that result 
in tire failure.
Overinflated or underinflated tires can 
affect vehicle handling and can fail 
suddenly, resulting in loss of vehicle 
control.
Unequal tire pressures can cause steering 
problems. You could lose control of your 
vehicle.
Unequal tire pressures from one side of the 
vehicle to the other can cause the vehicle 
to drift to the right or left.
Always drive with each tire inflated to the 
recommended cold tire inflation pressure.
CAUTION!
After inspecting or adjusting the tire pressure, 
always reinstall the valve stem cap. This will 
prevent moisture and dirt from entering the 
valve stem, which could damage the valve 
stem.
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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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452SERVICING AND MAINTENANCE  
limited driving capabilities and needs to be 
replaced immediately. A Run Flat tire is not 
repairable. When a Run Flat tire is changed 
after driving with underinflated tire condition, 
please replace the TPM sensor as it is not 
designed to be reused when driven under Run 
Flat mode 14 psi (96 kPa) condition.
NOTE:
TPM Sensor must be replaced after driving the 
vehicle on a flat tire condition.
It is not recommended driving a vehicle loaded 
at full capacity or to tow a trailer while a tire is in 
the Run Flat mode.
For more information  Úpage 327.
Tire Spinning 
When stuck in mud, sand, snow, or ice 
conditions, do not spin your vehicle's wheels 
above 30 mph (48 km/h) or for longer than 
30 seconds continuously without stopping.
For further information  Ú page 391.
Tread Wear Indicators 
Tread wear indicators are in the original 
equipment tires to help you in determining 
when your tires should be replaced.
Tire Tread
 These indicators are molded into the bottom of 
the tread grooves. They will appear as bands 
when the tread depth becomes a 1/16 of an 
inch (1.6 mm). When the tread is worn to the 
tread wear indicators, the tire should be 
replaced.
For further information  Ú
page 453.
Life Of Tire  
The service life of a tire is dependent upon 
varying factors including, but not limited to:
Driving style
Tire pressure - Improper cold tire inflation 
pressures can cause uneven wear patterns 
to develop across the tire tread. These 
abnormal wear patterns will reduce tread life, 
resulting in the need for earlier tire replace -
ment
Distance driven
Performance tires, tires with a speed rating of 
V or higher, and Summer tires typically have 
a reduced tread life. Rotation of these tires 
per the vehicle scheduled maintenance is 
highly recommended
WARNING!
Fast spinning tires can be dangerous. Forces 
generated by excessive wheel speeds may 
cause tire damage or failure. A tire could 
explode and injure someone. Do not spin your 
vehicle's wheels faster than 30 mph (48 km/h) 
for more than 30 seconds continuously when 
you are stuck, and do not let anyone near a 
spinning wheel, no matter what the speed.
1 — Worn Tire
2 — New Tire
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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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SERVICING AND MAINTENANCE457
Your wheels are susceptible to deterioration 
caused by salt, sodium chloride, magnesium 
chloride, calcium chloride, etc., and other road 
chemicals used to melt ice or control dust on 
dirt roads. Use a soft cloth or sponge and mild 
soap to wipe away promptly. Do not use harsh 
chemicals or a stiff brush. They can damage the 
wheel’s protective coating that helps keep them 
from corroding and tarnishing. When cleaning extremely dirty wheels including 
excessive brake dust, care must be taken in the 
selection of tire and wheel cleaning chemicals 
and equipment to prevent damage to the 
wheels. Mopar Wheel Treatment or Mopar 
Chrome Cleaner or their equivalent is 
recommended or select a non-abrasive, 
non-acidic cleaner for aluminum or chrome 
wheels.NOTE:
If you intend parking or storing your vehicle for 
an extended period after cleaning the wheels 
with wheel cleaner, drive your vehicle and apply 
the brakes to remove the water droplets from 
the brake components. This activity will remove 
the red rust on the brake rotors and prevent 
vehicle vibration when braking.
Dark Vapor Chrome, Black Satin Chrome, or 
Low Gloss Clear Coat Wheels
CAUTION!
Avoid products or automatic car washes that 
use acidic solutions or strong alkaline 
additives or harsh brushes. Many aftermarket 
wheel cleaners and automatic car washes 
may damage the wheel's protective finish. 
Such damage is not covered by the New 
Vehicle Limited Warranty. Only car wash soap, 
Mopar Wheel Cleaner or equivalent is 
recommended.
CAUTION!
Do not use scouring pads, steel wool, a bristle 
brush, metal polishes or oven cleaner. These 
products may damage the wheel's protective 
finish. Such damage is not covered by the 
New Vehicle Limited Warranty. Only car wash 
soap, Mopar Wheel Cleaner or equivalent is 
recommended.CAUTION!
If your vehicle is equipped with these 
specialty wheels, DO NOT USE wheel 
cleaners, abrasives, or polishing compounds. 
They will permanently damage this finish and 
such damage is not covered by the New 
Vehicle Limited Warranty. HAND WASH ONLY 
USING MILD SOAP AND WATER WITH A SOFT 
CLOTH. Used on a regular basis; this is all that 
is required to maintain this finish.
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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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