2022 RAM CHASSIS CAB tire size

178STARTING AND OPERATING
Towing Requirements — Tires
Do not attempt to tow a trailer while using a
compact spare tire.
Do not drive more than 50 mph (80 km/h) when
towing while using a full size spare tire.
Proper tire inflation pressures are essential to
the safe and satisfactory operation of your
vehicle.
Check the trailer tires for proper tire inflation
pressures before trailer usage.
Check for signs of tire wear or visible tire
damage before towing a trailer.
For the proper tire replacement procedures.
Replacing tires with a higher load carrying
capacity will not increase the vehicle's GVWR
and GAWR limits.
For further information Úpage 376.
Towing Requirements — Trailer Brakes
Do not interconnect the hydraulic brake system
or vacuum system of your vehicle with that of
the trailer. This could cause inadequate braking
and possible personal injury.
An electronically actuated trailer brake
controller is required when towing a trailer with
electronically actuated brakes. When towing a
trailer equipped with a hydraulic surge actuated brake system, an electronic brake controller is
not required.
Trailer brakes are recommended for trailers
over 1,000 lb (453 kg) and required for trailers
in excess of 2,000 lb (907 kg).Safety chains must always be used between
your vehicle and trailer. Always connect the
chains to the hook retainers of the vehicle
hitch. Cross the chains under the trailer
tongue and allow enough slack for turning
corners.
Vehicles with trailers should not be parked on
a grade. When parking, apply the parking
brake on the tow vehicle. Put the tow vehicle
transmission in PARK. For four-wheel drive
vehicles, make sure the transfer case is not in
NEUTRAL. Always, block or "chock" the trailer
wheels.
GCWR must not be exceeded.
Total weight must be distributed between the
tow vehicle and the trailer such that the
following four ratings are not exceeded
:
GVWR
GTW
GAWR
Tongue weight rating for the trailer hitch
utilized.
WARNING!
WARNING!
Do not connect trailer brakes to your vehicle's
hydraulic brake lines. It can overload your
brake system and cause it to fail. You might
not have brakes when you need them and
could have an accident.
Towing any trailer will increase your stopping
distance. When towing, you should allow for
additional space between your vehicle and the
vehicle in front of you. Failure to do so could
result in an accident.
CAUTION!
If the trailer weighs more than 1,000 lb (453 kg)
loaded, it should have its own brakes and they
should be of adequate capacity. Failure to do
this could lead to accelerated brake lining wear,
higher brake pedal effort, and longer stopping
distances.

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SAFETY261
prevent wheel lift due to other factors, such as
road conditions, leaving the roadway, or striking
objects or other vehicles.
NOTE:ERM is disabled any time the ESC is in “Full Off”
mode (if equipped). For a complete explanation of
the available ESC modes, see Ú page 261.
Electronic Stability Control (ESC)
ESC enhances directional control and stability of
the vehicle under various driving conditions. ESC
corrects for oversteering or understeering of the
vehicle by applying the brake of the appropriate wheel(s) to counteract the above conditions.
Engine power may also be reduced to help the
vehicle maintain the desired path.
Oversteer — when the vehicle is turning more
than appropriate for the steering wheel position.
Understeer — when the vehicle is turning less
than appropriate for the steering wheel position.
ESC uses sensors in the vehicle to determine the
vehicle path intended by the driver and compares
it to the actual path of the vehicle. When the actual
path does not match the intended path, ESC
applies the brake of the appropriate wheel to
assist in counteracting the oversteer or understeer
condition.
The ESC Activation/Malfunction Indicator Light
located in the instrument cluster will start to flash
as soon as the ESC system becomes active. The
ESC Activation/Malfunction Indicator Light also
flashes when the TCS is active. If the ESC
Activation/Malfunction Indicator Light begins to
flash during acceleration, ease up on the
accelerator and apply as little throttle as possible.
Be sure to adapt your speed and driving to the
prevailing road conditions.
WARNING!
Many factors, such as vehicle loading, road
conditions and driving conditions, influence the
chance that wheel lift or rollover may occur. ERM
cannot prevent all wheel lift or rollovers,
especially those that involve leaving the roadway
or striking objects or other vehicles. The
capabilities of an ERM-equipped vehicle must
never be exploited in a reckless or dangerous
manner which could jeopardize the user's safety
or the safety of others.
WARNING!

Electronic Stability Control (ESC) cannot
prevent the natural laws of physics from acting
on the vehicle, nor can it increase the traction
afforded by prevailing road conditions. ESC
cannot prevent accidents, including those
resulting from excessive speed in turns, driving
on very slippery surfaces, or hydroplaning. ESC
also cannot prevent accidents resulting from
loss of vehicle control due to inappropriate
driver input for the conditions. Only a safe,
attentive, and skillful driver can prevent acci -
dents. The capabilities of an ESC equipped
vehicle must never be exploited in a reckless or
dangerous manner which could jeopardize the
user’s safety or the safety of others.
Vehicle modifications, or failure to properly
maintain your vehicle, may change the handling
characteristics of your vehicle, and may nega -
tively affect the performance of the ESC system.
Changes to the steering system, suspension,
braking system, tire type and size or wheel size
may adversely affect ESC performance. Improp -
erly inflated and unevenly worn tires may also
degrade ESC performance. Any vehicle modifi-
cation or poor vehicle maintenance that
reduces the effectiveness of the ESC system
can increase the risk of loss of vehicle control,
vehicle rollover, personal injury and death.

6

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SAFETY269
(Continued)
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 Ú
page 412.
NOTE:
The TPMS is not intended to replace normal tire
care and maintenance or to provide warning of
a tire failure or condition.
If your vehicle is not equipped with the Tire Fill
Alert feature the TPMS should not be used as a
tire pressure gauge while adjusting your tire
pressure.
Driving on a significantly underinflated tire
causes the tire to overheat and can lead to tire
failure. Underinflation also reduces fuel effi -
ciency and tire tread life, and may affect the
vehicle’s handling and stopping ability.
The TPMS is not a substitute for proper tire
maintenance, and it is the driver’s responsibility
to maintain correct tire pressure using an accu -
rate tire pressure gauge, even if underinflation
has not reached the level to trigger illumination
of the TPMS Warning Light.
Seasonal temperature changes will affect tire
pressure, and the TPMS will monitor the actual
tire pressure in the tire.

Example: Tire Pressure Monitoring System Display

The Tire Pressure Monitoring System (TPMS) uses
wireless technology with wheel rim mounted
electronic sensors to monitor tire pressure levels.
Sensors, mounted to each wheel as part of the
valve stem, transmit tire pressure readings to the
receiver module.
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 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 pressure
always reinstall the valve stem cap. This will
prevent moisture and dirt from entering the
valve stem, which could damage the TPMS
sensor.
CAUTION!
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SAFETY271
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 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
in 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. There -
fore, 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 warning
limit, upon the next ignition switch cycle, the
TPMS Warning Light and a “LOW TIRE” message
will remain on and a chime will sound. In addi-
tion, the graphic in the instrument cluster will
still display a pressure value in a different color
and an “Inflate to XX” message.
After driving the vehicle for up to 20 minutes
above 15 mph (24 km/h), the TPMS Warning
Light will flash on and off for 75 seconds and
then remain on solid. In addition, the instrument
cluster will display a "SERVICE TPM SYSTEM"
message for a minimum of five seconds and
then display dashes (- -) in place of the pressure
value.
For each subsequent ignition switch cycle, a
chime will sound, the TPMS Warning Light will
flash on and off for 75 seconds and then remain
on solid, and the instrument cluster will display
a "SERVICE TPM SYSTEM" message for a
minimum of five seconds and then display
dashes (- -) in place of the pressure value.
Once you repair or replace the original road tire
and reinstall it on the vehicle in place of the
non-matching full size spare or compact spare,
the TPMS will update automatically. In addition,
the TPMS Warning Light will turn off and the
graphic in the instrument cluster will display a
new pressure value instead of dashes (- -), as
long as no tire pressure is below the low-pres -
sure warning limit in any of the four active road
tires. 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.
Trailer Tire Pressure Monitoring System
(TTPMS) — If Equipped
The Trailer Tire Pressure Monitoring System
(TTPMS) is a feature that displays the trailer tire
pressure values and warns the driver of a low tire
pressure event based on the driver’s set target tire
pressure value, through TTPMS settings found in
the radio.
The TTPMS monitors the pressure of each tire and
warns the driver through the instrument cluster,
when either a low tire pressure condition falls
below 25% of the driver’s set pressure or if a
system malfunction occurs. The instrument cluster
will display the actual tire pressure or dashes for 6

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376SERVICING AND MAINTENANCE
2. Rotate the bulb socket a quarter turn and pull it from the lamp assembly.

Removing Bulb Socket From Clearance Lamp

3. Pull the bulb straight from it's socket and replace.
TIRES
TIRE SAFETY INFORMATION
Tire safety information will cover aspects of the
following information: Tire Markings, Tire
Identification Numbers, Tire Terminology and
Definitions, Tire Pressures, and Tire Loading.
Tire Markings

Tire Markings

NOTE:
P (Passenger) — Metric tire sizing is based on US
design standards. P-Metric tires have the letter
“P” molded into the sidewall preceding the size
designation. Example: P215/65R15 95H.
European — Metric tire sizing is based on Euro -
pean design standards. Tires designed to this
standard have the tire size molded into the side -
wall beginning with the section width. The letter
"P" is absent from this tire size designation.
Example: 215/65R15 96H.
LT (Light Truck) — Metric tire sizing is based on
US design standards. The size designation for
LT-Metric tires is the same as for P-Metric tires
except for the letters “LT” that are molded into
the sidewall preceding the size designation.
Example: LT235/85R16.
Temporary spare tires are designed for tempo -
rary emergency use only. Temporary high pres -
sure compact spare tires have the letter “T” or
“S” molded into the sidewall preceding the size
designation. Example: T145/80D18 103M.
High flotation tire sizing is based on US design
standards and it begins with the tire diameter
molded into the sidewall. Example: 31x10.5
R15 LT.

1 — US DOT Safety Standards Code (TIN)

2 — Size Designation
3 — Service Description
4 — Maximum Load
5 — Maximum Pressure
6 — Treadwear, Traction and
Temperature Grades

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SERVICING AND MAINTENANCE377
TIRE SIZING CHART
EXAMPLE:
Example Size Designation: P215/65R15XL 95H, 215/65R15 96H, LT235/85R16C, T145/80D18 103M, 31x10.5 R15 LT
P = Passenger car tire size based on US design standards, or
"....blank...." = Passenger car tire based on European design standards, or
LT = Light truck tire based on US design standards, or
T or S = Temporary spare tire or
31 = Overall diameter in inches (in)
215, 235, 145 = Section width in millimeters (mm)
65, 85, 80 = Aspect ratio in percent (%)
Ratio of section height to section width of tire, or
10.5 = Section width in inches (in)
R = Construction code
"R" means radial construction, or
"D" means diagonal or bias construction
15, 16, 18 = Rim diameter in inches (in)
Service Description:
95 = Load Index
A numerical code associated with the maximum load a tire can carry
H = Speed Symbol
A symbol indicating the range of speeds at which a tire can carry a load corresponding to its load index under certain operating conditions
The maximum speed corresponding to the speed symbol should only be achieved under specified operating conditions (i.e., tire pressure, vehicle loading,
road conditions, and posted speed limits)
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378SERVICING AND MAINTENANCE
Tire Identification Number (TIN)
The TIN may be found on one or both sides of the tire; however, the date code may only be on one side. Tires with white sidewalls will have the full TIN, including
the date code, located on the white sidewall side of the tire. Look for the TIN on the outboard side of black sidewall tires as mounted on the vehicle. If the TIN is
not found on the outboard side, then you will find it on the inboard side of the tire.Load Identification:
Absence of the following load identification symbols on the sidewall of the tire indicates a Standard Load (SL) tire:
XL = Extra load (or reinforced) tire, or
LL
= Light load tire or
C, D, E, F, G = Load range associated with the maximum load a tire can carry at a specified pressure
Maximum Load – Maximum load indicates the maximum load this tire is designed to carry
Maximum Pressure – Maximum pressure indicates the maximum permissible cold tire inflation pressure for this tire
EXAMPLE:
EXAMPLE:
DOT MA L9 ABCD 0301
DOT = Department of Transportation
This symbol certifies that the tire is in compliance with the US Department of Transportation tire safety standards and is approved for highway use
MA = Code representing the tire manufacturing location (two digits)
L9 = Code representing the tire size (two digits)
ABCD = Code used by the tire manufacturer (one to four digits)
03 = Number representing the week in which the tire was manufactured (two digits)
03 means the 3rd week

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SERVICING AND MAINTENANCE379
Tire Terminology And Definitions
01 = Number representing the year in which the tire was manufactured (two digits)
01 means the year 2001
Prior to July 2000, tire manufacturers were only required to have one number to represent the year in which the tire was manufactured. Example: 031 could
represent the 3rd week of 1981 or 1991
Term Definition
B-pillarThe vehicle B-pillar is the structural member of the body located behind the
front door.
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. Inflation pressure is measured in
units of PSI (pounds per square inch) or kPa (kilopascals).
Maximum Inflation Pressure The maximum inflation pressure is the maximum permissible cold tire
inflation pressure for this tire. The maximum inflation pressure is molded into
the sidewall.
Recommended Cold Tire Inflation Pressure Vehicle manufacturer's recommended cold tire inflation pressure as shown
on the tire placard.
Tire Placard A label permanently attached to the vehicle describing the vehicle’s loading
capacity, the original equipment tire sizes and the recommended cold tire
inflation pressures.
EXAMPLE:
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