2023 RAM 1500 tire size

STARTING AND OPERATING179
(Continued)
Some trailers (such as boat trailers) will need to
recalibrate while loaded and unloaded.
NOTE:

The system may not detect a trailer in low light condi -
tions. In sunny conditions, the performance may be
degraded as shadows pass over the trailer.
 The driver is always responsible for safe operation of
truck and trailer.
 The driver is always in control of the truck as well as the
trailer and is responsible for controlling the throttle and
brakes.
 The system may not function when the camera lens is
blocked, blurred (covered with water, snow, ice, dirt,
etc) and will not work unless the tailgate is upright and
fully latched.
TOWING REQUIREMENTS
To promote proper break-in of your new vehicle drivetrain
components, the following guidelines are recommended. Perform the maintenance listed in the Scheduled
Servicing section for the proper maintenance intervals
Úpage 333. When towing a trailer, never exceed the
GAWR or GCWR ratings.
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.
 Replacing tires with a higher load carrying capacity will
not increase the vehicle's GVWR and GAWR limits.
 For further information
Úpage 370.
CAUTION!
Do not tow a trailer at all during the first 500 miles
(805 km) the new vehicle is driven. The engine, axle
or other parts could be damaged.
 Then, during the first 500 miles (805 km) that a
trailer is towed, do not drive over 50 mph (80 km/h)
and do not make starts at full throttle. This helps the
engine and other parts of the vehicle wear in at the
heavier loads.
WARNING!
Make certain that the load is secured in the trailer
and will not shift during travel. When trailering cargo
that is not fully secured, dynamic load shifts can
occur that may be difficult for the driver to control.
You could lose control of your vehicle and have a
collision.
 When hauling cargo or towing a trailer, do not over -
load your vehicle or trailer. Overloading can cause a
loss of control, poor performance or damage to
brakes, axle, engine, transmission, steering, suspen -
sion, chassis structure or tires.
 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!
4

23_DT_OM_EN_USC_t.book Page 179

264SAFETY
Electronic Roll Mitigation (ERM)
The ERM system anticipates the potential for wheel lift by
monitoring the driver’s steering wheel input and the speed
of the vehicle. When ERM determines that the rate of
change of the steering wheel angle and vehicle’s speed
are sufficient to potentially cause wheel lift, it then applies
the appropriate brake and may also reduce engine power
to lessen the chance that wheel lift will occur. ERM can
only reduce the chance of wheel lift occurring during
severe or evasive driving maneuvers; it cannot prevent
wheel lift due to other factors, such as road conditions,
leaving the roadway, striking objects or other vehicles.
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 these
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 hydro -
planing. 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 accidents. The capabil -
ities 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 characteris -
tics of your vehicle, and may negatively 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. Improperly inflated and unevenly worn
tires may also degrade ESC performance. Any vehicle
modification 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.

23_DT_OM_EN_USC_t.book Page 264

SAFETY273
Automatic Trailer Detection
There are two modes of operation for the detection of the
trailer length:
Automatic Mode — When “Auto Mode” is selected, the
system will use the blind spot sensors to automatically
determine the presence and length of a trailer. The
presence of a trailer will be detected using the blind
spot radar within 90 seconds of forward movement of
the vehicle. The vehicle must be moving above 6 mph
(10 km/h) to activate the feature. Once the trailer has
been detected, the system will default to the maximum
blind spot zone until the length has been verified. You
will see “Auto” in the instrument panel cluster .
 Maximum Mode — When “Max Mode” is selected, the
system will default to the maximum blind spot zone
regardless of what size trailer is attached .
NOTE:Selected setting is stored when the ignition is placed in the
OFF position. To change this setting, it must be selected
through the Uconnect Settings
Úpage 191.
Trailer Length Detection
Once the trailer presence has been established, the trailer
length will be established (by making a 90 degree turn)
and then the trailer length category (example 10-20 ft
(3 m to 6 m)) will be displayed. This can take up to
30 seconds after completing the turn.
NOTE:During the same ignition cycle, if the vehicle is at a
standstill for a minimum of 90 seconds, a new “trailer
detection request” is enabled by the system once the
vehicle resumes motion.
The maximum trailer length supported by the Trailer
Merge Assist feature is 39.5 ft (12 m). Trailer length is
considered the forward most portion of the trailer hitch to
the rearward most portion of the body, fascia/bumper, or
ramp of the trailer.
The maximum width supported by the Trailer Merge Assist
feature is 8.5 ft (2.59 m). Trailer width is measured at the
widest portion of the trailer and may include wheels, tires,
finders, or rails.
NOTE:Fifth wheel or gooseneck trailers are not supported by
Trailer Merge Assist.
NOTE:The ability to detect a trailer may be degraded in crowded
or busy environments. Busy parking lots, narrow areas
surrounded with trees, or any other crowded area may
prevent the radar sensors from being able to adequately
detect the trailer. The system will try to detect a trailer at
every ignition cycle or 90 seconds of standstill.

Trailer Length Detection

Trailer length will be identified and placed into one of the
following categories:
 Trailer length up to 10 ft (3 m) — Blind spot zone will be
adjusted to 10 ft (3 m) .
 Trailer length between 10 ft to 20 ft
(3 m to 6 m) — Blind spot zone will be adjusted to
20 ft (6 m) .
 Trailer length between 20 ft to 30 ft
(6 m to 9 m) — Blind spot zone will be adjusted to
30 ft (9 m) .
 Trailer length between 30 ft and 39.5 ft
(9 m to 12 m) — Blind spot zone will be adjusted to
Max distance .
1 — Trailer Length
2 — Trailer Hitch
3 — Trailer Width
6

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SAFETY277
TIRE PRESSURE MONITORING SYSTEM
(TPMS)
TPMS will warn the driver of a low tire pressure based on
the vehicle recommended cold placard pressure.
NOTE:The TPMS Warning Light will illuminate in the instrument
cluster and a chime will sound when tire pressure is low in
one or more of the four active road tires. In addition, the
instrument cluster will display a graphic showing the
pressure values of each tire with the low tire pressure
values in a different color, or the Uconnect radio will
display a TPMS message; when this occurs you must
increase the tire pressure to the recommended cold
placard pressure in order for the TPMS Warning Light to
turn off.
The tire pressure will vary with temperature by about 1 psi
(7 kPa) for every 12°F (6.5°C). This means that when the
outside temperature decreases, the tire pressure will
decrease. Tire 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 370 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
Úpage 402.
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 original equip -
ment 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 equip -
ment 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 func -
tion checked.
 After inspecting or adjusting the tire pressure always
reinstall the valve stem cap. This will prevent mois -
ture and dirt from entering the valve stem, which
could damage the TPMS sensor.
6

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SAFETY279
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 TPM 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 TPM
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 Monitoring 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 warning limit, upon
the next ignition switch cycle, the Tire Pressure
Monitoring System (TPMS) Warning Light and a
“LOW TIRE” message will remain on and a chime will
sound. In addition, 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 Tire Pressure Monitoring
System (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 Tire Pressure Monitoring System (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 Tire Pressure Monitoring
System (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-pressure 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.
Tire Fill Alert
This feature notifies the user when the placard tire
pressure is attained while inflating or deflating the tire.
You may choose to disable or enable the Tire Fill Alert
feature through use of the Uconnect Settings in the radio.
NOTE:
Only one tire can be filled at a time when using the Tire
Fill Alert system.
 The Tire Fill Alert feature cannot be entered if an
existing TPMS fault is set to “active” or if the system is
in deactivation mode (if equipped).
6

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370SERVICING AND MAINTENANCE
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 European
design standards. Tires designed to this standard have
the tire size molded into the sidewall 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 temporary
emergency use only. Temporary high pressure 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 stan -
dards 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

23_DT_OM_EN_USC_t.book Page 370

SERVICING AND MAINTENANCE371
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)
8

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372SERVICING AND MAINTENANCE
Tire Identification Number (TIN)
The Tire Identification Number (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)

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