2019 RAM CHASSIS CAB Owners Manual

SERVICING AND MAINTENANCE 455
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.
Over-inflation 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 judge -
ment when determining proper inflation. Tires may look
properly inflated even when they are under-inflated.
• 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 cold
tire inflation pressure must not exceed the maximum infla -
tion 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 tempera -
ture 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. 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.
7

456 SERVICING AND MAINTENANCE
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, main -
taining 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 autho -
rized 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 (side -
wall 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 addi -
tional information.
Damaged Run Flat tires, or Run Flat tires that have experi -
enced 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.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.

SERVICING AND MAINTENANCE 457
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 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.
See the tire pressure monitoring section for more informa -
tion. 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.
Refer to “Freeing A Stuck Vehicle” in “In Case Of Emer -
gency” for further information.
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.
7

458 SERVICING AND MAINTENANCE
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. Refer to “Replacement Tires” in this section for further infor -
mation.
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 replacement.
• Distance driven.
• Performance tires, tires with a speed rating of V or higher,
and Summer tires typically have a reduced tread life. Rota -
tion of these tires per the vehicle scheduled maintenance is
highly recommended.1 — Worn Tire
2 — New Tire
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 sudden tire failure. You could
lose control and have a collision resulting in serious
injury or death.

SERVICING AND MAINTENANCE 459
(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 expo -
sure 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. The manufacturer
strongly recommends that you use tires equivalent to the
originals in size, quality and performance when replacement
is needed. Refer to the paragraph on “Tread Wear Indica -
tors” in this section. Refer to the Tire and Loading Informa -
tion 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.
See the Tire Sizing Chart example found in the “Tire Safety
Information” section of this manual for more information
relating to the Load Index and Speed Symbol of a tire. 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 orig -
inal 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!
• Do not use a tire, wheel size, load rating, or speed rating
other than that specified for your vehicle. Some combi -
nations of unapproved tires and wheels may change
suspension dimensions and performance characteris -
tics, resulting in changes to steering, handling, and
braking of your vehicle. This can cause unpredictable
handling and stress to steering and suspension compo -
nents. 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. 7

460 SERVICING AND MAINTENANCE
Tire Types
All Season Tires — If Equipped
All Season tires provide traction for all seasons (Spring,
Summer, Fall, 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 condi -
tions, 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 tempera -
tures 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.• 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.
• 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.

SERVICING AND MAINTENANCE 461
Snow Tires
Some areas of the country require the use of snow tires
during the Winter. Snow tires can be identified by a “moun -
tain/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. 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 Emer -
gency” for further information.
Refer to the “Towing Requirements - Tires” in “Starting And
Operating” for restrictions when towing with a spare tire
designated for temporary emergency use.
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. 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.
7

462 SERVICING AND MAINTENANCE
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 conven -
tional 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 collaps -
ible 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.
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. 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.