inflation pressure RAM CHASSIS CAB 2016 User Guide

judgement 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.
CAUTION!After inspecting or adjusting the tire pressure, al-
ways reinstall the valve stem cap. This will prevent
moisture and dirt from entering the valve stem,
which could damage the valve stem.
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 inflation pressure molded into the tire side-
wall.
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. 5STARTING AND OPERATING 473

Tire Pressures For High Speed Operation
The manufacturer advocates driving at safe speeds and
within posted speed limits. Where speed limits or condi-
tions 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 opera-
tion. Refer to your authorized tire dealer or original
equipment vehicle dealer for recommended safe operat-
ing speeds, loading and cold tire inflation pressures.
WARNING!High speed driving with your vehicle under maxi-
mum 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). Tire Maintenance And Replacement
You should follow all maintenance procedures specified
by the manufacturer of this vehicle’s tires. The tires
originally installed on this vehicle were designed to
conform to EPA greenhouse gas standards and NHTSA
fuel economy standards.
If you need to replace your tires, you should do so with
tires that meet those standards. Check with your autho-
rized dealer or with the tire manufacturer for appropriate
replacement tires.474 STARTING AND OPERATING

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 pro-
hibit studded tires; therefore, local laws should be
checked before using these tire types.
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 immedi-
ately. A Run Flat tire is not repairable.
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 infor-
mation.
Spare Tires — If Equipped
NOTE: For vehicles equipped with Tire Service Kit
instead of a spare tire, please refer to “Tire Service Kit” in
“What To Do In Emergencies” for further information. 5STARTING AND OPERATING 477

WARNING!Limited-use spares are for emergency use only. In-
stallation of this limited-use spare tire affects vehicle
handling. With this tire, do not drive more than the
speed listed on the limit-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.
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 stop-
ping. Refer to “Freeing A Stuck Vehicle” in “What To Do In
Emergencies” for further information.
WARNING!Fast spinning tires can be dangerous. Forces gener-
ated by excessive wheel speeds may cause tire dam-
age or failure. A tire could explode and injure some-
one. Do not spin your vehicle’s wheels faster than
30 mph (48 km/h) for more than 30 seconds continu-
ously when you are stuck, and do not let anyone near
a spinning wheel, no matter what the speed.
Tread Wear Indicators
Tread wear indicators are in the original equipment tires
to help you in determining when your tires should be
replaced.480 STARTING AND OPERATING

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 information.
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 reducedTire Tread1—WornTire
2—NewTire
5STARTING AND OPERATING 481

tread life. Rotation of these tires per the vehicle main-
tenance schedule is highly recommended.
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.
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. The manu-
facturer strongly recommends that you use tires equiva-
lent to the originals in size, quality and performance
when replacement is needed. Refer to the paragraph on
“Tread Wear Indicator”. 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. See the Tire Sizing Chart ex-
ample 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 original wheels.
It is recommended you contact your authorized tire
dealer or original equipment dealer with any questions482 STARTING AND OPERATING

SUPPLEMENTAL TIRE PRESSURE INFORMATION
— IF EQUIPPED
A light load vehicle condition is defined as two passen-
gers [150 lbs (68 kg) each] plus 200 lbs (90 kg) of cargo.
Cold tire inflation pressures for a lightly loaded vehicle
will be found on the face of the driver’s door. TIRE CHAINS (TRACTION DEVICES)
Use of traction devices require sufficient tire-to-body
clearance. Follow these recommendations to guard
against damage.
• Traction device must be of proper size for the tire, as
recommended by the traction device manufacturer.
Please follow the table below for proper tire size, chain
type, and axle recommendations:
Vehicle Axle Recommendations Tire Sizes Chain Class
Chassis Cab 3500 (Single
Rear Wheel) Models Rear Only LT265/70R18E U Class
Chassis Cab 3500 (Dual
Rear Wheel) 4X2 Models Rear Only LT235/80R17E U Class
Chassis Cab 3500 (Dual
Rear Wheel) 4X4 Models Front/Rear LT235/80R17E U Class
Chassis Cab 4500/5500
Models Rear Only 225/70R19.5G U Class484 STARTING AND OPERATING

in incorrect locations for the pressure values displayed
in the Instrument Cluster.
CAUTION!• 4500/5500 Dual Rear Tires may only have one
approved direction of rotation. This is to accommo-
date the asymmetrical design (tread pattern) of the
On/Off road tire.
• When replacing a flat, the spare tire may have to be
remounted on the rim or installed at a different
location to maintain the correct placement of the
tire on the wheel relative to the tire/wheel position
on the vehicle. For example, if the spare is used to
replace an outer rear tire it will have to be re-
mounted on the rim so that the wheel is dished
inward. That way the tread design of asymmetrical
tires will maintain proper position. TIRE PRESSURE MONITOR SYSTEM (TPMS)
The Tire Pressure Monitor System (TPMS) will warn the
driver of a low tire pressure based on the vehicle recom-
mended cold placard pressure.
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. Refer to “Tires – General Information”
in “Starting And Operating” for information on how to
properly inflate the vehicle’s tires. The tire pressure will488 STARTING AND OPERATING

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 op-
eration 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 be-
come 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 al-
ways reinstall the valve stem cap. This will prevent (Continued) CAUTION! (Continued)moisture and dirt from entering the valve stem,
which could damage the TPMS sensor.
NOTE:
• The TPMS is not intended to replace normal tire care
and maintenance or to provide warning of a tire failure
or condition.
• The TPMS should not be used as a tire pressure gauge
while adjusting your tire pressure.
• Driving on a significantly under-inflated tire causes
the tire to overheat and can lead to tire failure.
Under-inflation also reduces fuel efficiency and tire
tread life, and may affect the vehicle’s handling and
stopping ability.
• The TPMS is not a substitute for proper tire mainte-
nance, and it is the driver ’s responsibility to maintain490 STARTING AND OPERATING

correct tire pressure using an accurate tire pressure
gauge, even if under-inflation has not reached the level
to trigger illumination of the “Tire Pressure Monitor-
ing Telltale Light.”
• Seasonal temperature changes will affect tire pressure,
and the TPMS will monitor the actual tire pressure in
the tire.
Base System — If Equipped
The Tire Pressure Monitor 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.
NOTE: It is particularly important for you to check the
tire pressure in all of the tires on your vehicle monthly
and to maintain the proper pressure.
The TPMS consists of the following components: • Receiver module
• Four TPM sensors
• TPM Telltale Light
The matching full size spare wheel and tire assembly (if
equipped) has a TPM sensor. The matching full size spare
can be used in place of any of the four road tires. The
TPMS will only monitor the pressure in the full size spare
when it is used in place of a road tire. Otherwise, a spare
with a pressure below the low-pressure limit will not
cause the “Tire Pressure Monitoring Telltale Light” to
illuminate or the chime to sound.
Premium System
The Tire Pressure Monitor 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. 5STARTING AND OPERATING 491