tire pressure Ram 3500 2020 Owner's Guide

256STARTING AND OPERATING
AIR SUSPENSION SYSTEM — IF EQUIPPED
DESCRIPTION
This air suspension system is a rear leveling ride
height system. The main purpose of this system
is to maintain the truck’s rear ride height level.
There are two selectable heights that can be
chosen based on your operating conditions.
The system requires that the ignition be in the
ON/RUN position or the engine running with
zero vehicle speed for all user requested
changes and load leveling.

Rear Leveling Ride Height Switch
Normal Ride Height (NRH)
– This is the standard
position of the suspension and is meant for
normal driving. It will automatically adjust to
maintain the rear ride height as conditions
change.
Alternate Trailer Height (ATH) – Lowers the
vehicle approximately 1 inch (25 mm) for a level
truck, to be used as required while trailer
towing. It will automatically adjust to maintain
the rear ride height as conditions change.
Trailer Decoupling/Unloading - The air
suspension system will continue to load level
after the vehicle has been turned off for
10 minutes without compressor activation. This
allows for easy removal of a trailer and/or load
from the back of the truck by maintaining the
ride height. After 10 minutes you will need to
turn the ignition to the run position for the air
suspension to re-level due to addition/removal
of load in the vehicle. If the air suspension
system is disabled using the settings menu (Tire
Jack Mode, Transport Mode, Alignment Mode,
or Bed Lowering Mode) the system will remain
disabled when the vehicle is turned off.
Reactivating the air suspension can be
accomplished via the settings menu or driving the vehicle above 5 mph (8 km/h) for Tire Jack
Mode, Alignment Mode, Transport Mode and
Bed Lowering Mode.
NOTE:
Most 3500 models will not lower to Alternate
Trailer Height (ATH) when unloaded.
Refer to “Trailer Towing” in “Starting And
Operating” for further information.
AIR SUSPENSION MODES
The air suspension system has multiple modes
to protect the system in unique situations:
Tire/Jack Mode
To assist with changing a tire, the air
suspension system has a feature which allows
the automatic leveling to be disabled. This
mode is intended to be enabled with the engine
running. Refer to “Instrument Cluster Display”
WARNING!
The air suspension system uses a high
pressure volume of air to operate the system.
To avoid personal injury or damage to the
system, see an authorized dealer for service.

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STARTING AND OPERATING263
They are normally full of debris from previous
vehicles getting stuck. As a good practice
before entering any mud hole, get out and
determine how deep it is, if there are any
hidden obstacles and if the vehicle can be
safely recovered if stuck.
Sand – Soft sand is very difficult to travel
through with full tire pressure. When crossing
soft sandy spots in a trail, maintain your
vehicle's momentum and do not stop. The
key to driving in soft sand is using the appro -
priate tire pressure, accelerating slowly,
avoiding abrupt maneuvers and maintaining
the vehicle's momentum. If you are going to
be driving on large soft sandy areas or dunes,
reduce your tire pressure to a minimum of
15 psi (103 kPa) to allow for a greater tire
surface area. Reduced tire pressure will dras -
tically improve your traction and handling,
while driving on the soft sand, but you must
return the tires to normal air pressure before
driving on pavement or other hard surfaces.
Be sure you have a way to air the tires back
up prior to reducing the pressure.
CROSSING OBSTACLES (ROCKS AND
O
THER HIGH POINTS)
While driving off road, you will encounter many
types of terrain. These varying types of terrain
bring different types of obstacles. Before
proceeding review the path ahead to determine
the correct approach and your ability to safely
recover the vehicle if something goes wrong.
Keeping a firm grip on the steering wheel, bring
the vehicle to a complete stop and then inch the
vehicle forward until it makes contact with the
object. Apply the throttle lightly while holding a
light brake pressure and ease the vehicle up
and over the object.
Using A Spotter
There are many times where it is hard to see the
obstacle or determine the correct path.
Determining the correct path can be extremely
difficult when you are confronting many
obstacles. In these cases have someone guide
you over, through, or around the obstacle. Have
the person stand a safe distance in front of you
where they can see the obstacle, watch your
tires and undercarriage, and guide you through.
Crossing Large Rocks
When approaching large rocks, choose a path
which ensures you drive over the largest with
your tires. This will lift your undercarriage over
the obstacle. The tread of the tire is tougher and
thicker than the side wall and is designed to
take the abuse. Always look ahead and make
every effort to cross the large rocks with your
tires.
CAUTION!
Reduced tire pressures may cause tire
unseating and total loss of air pressure. To
reduce the risk of tire unseating, while at a
reduced tire pressure, reduce your speed and
avoid sharp turns or abrupt maneuvers.
WARNING!
Crossing obstacles can cause abrupt steering
system loading which could cause you to
loose control of your vehicle.
CAUTION!
Never attempt to straddle a rock that is
large enough to strike your axles or under -
carriage.
Never attempt to drive over a rock which is
large enough to contact the door sills.
5

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STARTING AND OPERATING267
Crossing Puddles, Pools, Flooded Areas Or
Other Standing Water – Puddles, pools,
flooded or other standing water areas
normally contain murky or muddy waters.
These water types normally contain hidden
obstacles and make it difficult to determine
an accurate water depth, approach angle,
and bottom condition. Murky or muddy water
holes are where you want to hook up tow
straps prior to entering. This makes for a
faster, cleaner and easier vehicle recovery. If
you are able to determine you can safely
cross, than proceed using the low and slow
method.
Crossing Ditches, Streams, Shallow Rivers Or
Other Flowing Water – Flowing water can be
extremely dangerous. Never attempt to cross
a fast running stream or river even in shallow
water. Fast moving water can easily push
your vehicle downstream sweeping it out of
control. Even in very shallow water, a high
current can still wash the dirt out from around your tires putting you and your vehicle
in jeopardy. There is still a high risk of
personal injury and vehicle damage with
slower water currents in depths greater than
the vehicle's running ground clearance. You
should never attempt to cross flowing water
which is deeper than the vehicle's running
ground clearance. Even the slowest current
can push the heaviest vehicle downstream
out of control if the water is deep enough to
push on the large surface area of the
vehicle's body. Before you proceed deter
-
mine the speed of the current, the water's
depth, approach angle, bottom condition and
if there are any obstacles, then cross at an
angle heading slightly upstream using the
low and slow technique.
AIRING DOWN FOR OFF-ROAD DRIVING

Running lower tire pressure off-road can improve
your ride comfort and vehicle traction. Reducing
the tire air pressure allows the tire to bulge
slightly, improving its surface area for better
flotation and ability to mold or form to the ground
contour. Different terrain, tires, and vehicles
require different tire pressure. Hard surfaces like
rock and heavier vehicles require higher
pressures than softer surfaces such as sand and
lighter vehicles. You will need to experiment to
determine what is right for your situation. It is
easier and faster to let air out than it is to replace
it. Start high and lower it as required. Remember
you must return the tires to normal air pressure
before driving on road or at highway conditions.
Be sure you have a way to return the tires to their
normal on road air pressure.

CAUTION!
Muddy waters can reduce the cooling system
effectiveness by depositing debris onto the
radiator.
WARNING!
Never drive through fast moving deep water. It
can push your vehicle downstream, sweeping
it out of control. This could put you and your
passengers at risk of injury or drowning.CAUTION!
Reduced tire pressure increases the risk of
tire damage and may cause tire unseating
with total loss of air pressure. To reduce the
risk of tire unseating, while at a reduced tire
pressure, drive at slower speeds and avoid
sharp turns or abrupt maneuvers.
5

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324STARTING AND OPERATING
system to operate properly at temperatures
below 12°F (-11°C). If your vehicle is not in
operation for an extended period of time with
temperatures below 12°F (-11°C), the DEF in
the tank may freeze. If the tank is overfilled and
freezes, it could be damaged. Therefore, do not
overfill the DEF tank.
Extra care should be taken when filling with
portable containers to avoid overfilling. Note the
level of the DEF gauge in your instrument
cluster. You may safely add a maximum of
2 Gallons (7.5 Liters) of DEF from portable
containers when your DEF gauge is reading
½ full.
VEHICLE LOADING
GROSS VEHICLE WEIGHT RATING
(GVWR)
The GVWR is the total permissible weight of your
vehicle including driver, passengers, vehicle,
options and cargo. The label also specifies
maximum capacities of front and rear axle
systems (GAWR). Total load must be limited so
GVWR and front and rear GAWR are not
exceeded.
PAYLOAD
The payload of a vehicle is defined as the
allowable load weight a truck can carry,
including the weight of the driver, all
passengers, options and cargo.
GROSS AXLE WEIGHT RATING (GAWR)
The GAWR is the maximum permissible load on
the front and rear axles. The load must be
distributed in the cargo area so that the GAWR
of each axle is not exceeded.
Each axle GAWR is determined by the
components in the system with the lowest load
carrying capacity (axle, springs, tires or wheels).
Heavier axles or suspension components
sometimes specified by purchasers for
increased durability does not necessarily
increase the vehicle's GVWR.
TIRE SIZE
The tire size on the Vehicle Certification Label
represents the actual tire size on your vehicle.
Replacement tires must be equal to the load
capacity of this tire size.
RIM SIZE
This is the rim size that is appropriate for the tire
size listed.
INFLATION PRESSURE
This is the cold tire inflation pressure for your
vehicle for all loading conditions up to full
GAWR.
CURB WEIGHT
The curb weight of a vehicle is defined as the
total weight of the vehicle with all fluids,
including vehicle fuel, at full capacity
conditions, and with no occupants or cargo
loaded into the vehicle. The front and rear curb
weight values are determined by weighing your
vehicle on a commercial scale before any
occupants or cargo are added.
LOADING
The actual total weight and the weight of the
front and rear of your vehicle at the ground can
best be determined by weighing it when it is
loaded and ready for operation.

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STARTING AND OPERATING331
(Continued)
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. Refer to “Tires” in “Servicing And
Maintenance” for proper tire inflation proce -
dures.
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. Refer to
“Tires” in “Servicing And Maintenance” for
the proper inspection procedure.
When replacing tires, refer to “Tires” in
“Servicing And Maintenance” for the proper
tire replacement procedures. Replacing tires
with a higher load carrying capacity will not
increase the vehicle's GVWR and GAWR
limits.
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 inad -
equate 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 lbs (453 kg) and required for
trailers in excess of 2,000 lbs (907 kg).
When hauling cargo or towing a trailer, do
not overload your vehicle or trailer. Over -
loading can cause a loss of control, poor
performance or damage to brakes, axle,
engine, transmission, steering, suspension,
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.
WARNING! (Continued)
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! (Continued)
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344STARTING AND OPERATING
(Continued)
OFF-ROAD DRIVING TIPS
Care should be taken when attempting to climb
steep hills or driving diagonally across a hill or
slope. If natural obstacles force you to travel
diagonally up or down a hill, choose a mild angle
and keep as little side tilt as possible. Keep the
vehicle moving and make turns slowly and
cautiously.
If you must back down a hill, back straight down
using REVERSE gear. Never back down in
NEUTRAL or diagonally across the hill.
When driving over sand, mud, and other soft
terrain, shift to low gear and drive steadily.
Apply the accelerator slowly to avoid spinning
the wheels.
Do not reduce the tire pressures for this type of
driving.Driving through standing water limits your
vehicle’s braking capabilities, which
increases stopping distances. Therefore,
after driving through standing water, drive
slowly and lightly press on the brake pedal
several times to dry the brakes.
Failure to follow these warnings may result
in injuries that are serious or fatal to you,
your passengers, and others around you.
CAUTION!
Always check the depth of the standing
water before driving through it. Never drive
through standing water that is deeper than
the bottom of the tire rims mounted on the
vehicle.
Determine the condition of the road or the
path that is under water and if there are any
obstacles in the way before driving through
the standing water.
WARNING! (Continued)
Do not exceed 5 mph (8 km/h) when
driving through standing water. This will
minimize wave effects.
Driving through standing water may cause
damage to your vehicle’s drivetrain compo -
nents. Always inspect your vehicle’s fluids
(i.e., engine oil, transmission, axle, etc.) for
signs of contamination (i.e., fluid that is
milky or foamy in appearance) after driving
through standing water. Do not continue to
operate the vehicle if any fluid appears
contaminated, as this may result in further
damage. Such damage is not covered by
the New Vehicle Limited Warranty.
Getting water inside your vehicle’s engine
can cause it to lock up and stall out, and
cause serious internal damage to the
engine. Such damage is not covered by the
New Vehicle Limited Warranty.
CAUTION! (Continued)

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372IN CASE OF EMERGENCY
6. Finish tightening the lug nuts. Push down on
the lug wrench while at the end of the
handle for increased leverage. Tighten the
lug nuts in a star pattern until each nut has
been tightened twice. For the correct lug nut
torque refer to “Wheel And Tire Torque
Specifications” in “Technical Specifi -
cations”. If in doubt about the correct
tightness, have them checked with a torque
wrench by an authorized dealer or service
station.
7. Install the wheel center cap and remove the wheel blocks. Do not install chrome or
aluminum wheel center caps on the spare
wheel. This may result in cap damage. 8. Lower the jack to its fully closed position.
Stow the replaced tire, jack, and tools as
previously described.
NOTE:
The bottle jack will not lower by turning the dial
(thumbwheel) by hand, it may be necessary to
use the jack driver in order to lower the jack.
9. Adjust the tire pressure when possible.
NOTE:
Do not oil wheel studs. For chrome wheels, do
not substitute with chrome plated lug nuts.
TO STOW THE FLAT OR SPARE
NOTE:
Have the flat tire repaired or replaced immedi -
ately.

1. Turn the wheel so that the valve stem is facing the ground and toward the rear of
the vehicle for convenience in checking the
spare tire inflation. Slide the wheel retainer
through the center of the wheel.

Reinstalling The Retainer

2. Lift the spare tire with one hand to give clearance to tilt the retainer at the end of
the cable and position it properly across the
wheel opening.
WARNING!
A loose tire or jack thrown forward in a
collision or hard stop, could endanger the
occupants of the vehicle. Always stow the jack
parts and the spare tire in the places
provided.
WARNING!
A loose tire or jack thrown forward in a
collision or hard stop could endanger the
occupants of the vehicle. Always stow the jack
parts and the spare tire in the places
provided. Have the deflated (flat) tire repaired
or replaced immediately.

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380IN CASE OF EMERGENCY
FREEING A STUCK VEHICLE
If your vehicle becomes stuck in mud, sand, or
snow, it can often be moved using a rocking
motion. Turn the steering wheel right and left to
clear the area around the front wheels. Then
shift back and forth between DRIVE (D) and
REVERSE (R), while gently pressing the
accelerator. Use the least amount of
accelerator pedal pressure that will maintain
the rocking motion, without spinning the wheels
or racing the engine.
NOTE:
For trucks equipped with an 8–speed trans -
mission, shifts between DRIVE and REVERSE
can only be achieved at wheel speeds of
5 mph (8 km/h) or less. Whenever the trans -
mission remains in NEUTRAL (N) for more
than two seconds, you must press the brake
pedal to engage DRIVE or REVERSE.
Push the “ESC OFF” switch, to place the Elec -
tronic Stability Control (ESC) system in
“Partial Off” mode, before rocking the
vehicle. Refer to “Electronic Brake Control
System” in “Safety” for further information.
Once the vehicle has been freed, push the
“ESC OFF” switch again to restore “ESC On”
mode.WARNING!
You or others can be badly burned by hot
engine coolant (antifreeze) or steam from
your radiator. If you see or hear steam coming
from under the hood, do not open the hood
until the radiator has had time to cool. Never
try to open a cooling system pressure cap
when the radiator or coolant bottle is hot.
CAUTION!
Driving with a hot cooling system could
damage your vehicle. If the temperature
gauge reads HOT (H), pull over and stop the
vehicle. Idle the vehicle with the air
conditioner turned off until the pointer drops
back into the normal range. If the pointer
remains on HOT (H), and you hear continuous
chimes, turn the engine off immediately and
call for service.
WARNING!
Fast spinning tires can be dangerous. Forces
generated by excessive wheel speeds may
cause damage, or even failure, of the axle
and tires. A tire could explode and injure
someone. Do not spin your vehicle's wheels
faster than 30 mph (48 km/h) or for longer
than 30 seconds continuously without
stopping when you are stuck and do not let
anyone near a spinning wheel, no matter
what the speed.

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385
SERVICING AND MAINTENANCE
SCHEDULED SERVICING — GAS ENGINE
Your vehicle is equipped with an automatic oil
change indicator system. The oil change
indicator system will remind you that it is time to
take your vehicle in for scheduled maintenance.

Based on engine operation conditions, the oil
change indicator message will illuminate. This
means that service is required for your vehicle.
Operating conditions such as frequent
short-trips, trailer tow, extremely hot or cold
ambient temperatures, and E85 fuel usage will
influence when the “Oil Change Required”
message is displayed. Severe Operating
Conditions can cause the change oil message to
illuminate as early as 3,500 miles (5,600 km)
since last reset. Have your vehicle serviced as
soon as possible, within the next 500 miles
(805 km).

An authorized dealer will reset the oil change
indicator message after completing the
scheduled oil change.If a scheduled oil change is performed by
someone other than an authorized dealer, the
message can be reset by referring to the steps
described under “Instrument Cluster Display” in
“Getting To Know Your Instrument Panel”.
NOTE:
Under no circumstances should oil change
intervals exceed 8,000 miles (13,000 km),
12 months or 350 hours of engine run time,
whichever comes first. The 350 hours of engine
run or idle time is generally only a concern for
fleet customers.
Severe Duty All Models
NOTE:
Change Engine Oil at 4,000 miles (6,500 km) or
350 hours of engine run time if the vehicle is
operated in a dusty and off road environment or
is operated predominantly at idle, or only very
low engine RPM. This type of vehicle use is
considered Severe Duty.
Once A Month Or Before A Long Trip:Check engine oil level
Check windshield washer fluid level
Check tire pressure and look for unusual
wear or damage. Rotate tires at the first sign
of irregular wear, even if it occurs before the
oil indicator system turns on.
Check the fluid levels of the coolant reservoir,
brake master cylinder, power steering and
automatic transmission (six-speed only) and
fill as needed
Check function of all interior and exterior
lights7

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418SERVICING AND MAINTENANCE
Engine Coolant Checks
Check the engine coolant (antifreeze)
protection every 12 months (before the onset of
freezing weather, where applicable). If the
engine coolant (antifreeze) is dirty or rusty in
appearance, the system should be drained,
flushed and refilled with fresh coolant. Check
the front of the A/C condenser (if equipped) or
radiator for any accumulation of bugs, leaves,
etc. If dirty, clean by gently spraying water from
a garden hose vertically down the face of the
A/C condenser (if equipped) or the back of the
radiator core.
Check the engine cooling system hoses for
brittle rubber, cracking, tears, cuts and
tightness of the connection at the coolant
recovery bottle and radiator. Inspect the entire
system for leaks.
DO NOT REMOVE THE COOLANT PRESSURE CAP
WHEN THE COOLING SYSTEM IS HOT.
Cooling System — Drain, Flush And Refill
NOTE:
Some vehicles require special tools to add
coolant properly. Failure to fill these systems
properly could lead to severe internal engine damage. If any coolant is needed to be added to
the system please contact an authorized
dealer.
If the engine coolant (antifreeze) is dirty or
contains visible sediment, have an authorized
dealer clean and flush with OAT coolant
(antifreeze) (conforming to MS.90032).
Refer to the “Maintenance Plan” in this section
for the proper maintenance intervals.
Selection Of Coolant
Refer to “Fluids And Lubricants” in “Technical
Specifications” for further information.
NOTE:
Mixing of engine coolant (antifreeze) other
than specified Organic Additive Technology
(OAT) engine coolant (antifreeze), may result
in engine damage and may decrease corro
-
sion protection. Organic Additive Technology
(OAT) engine coolant is different and should
not be mixed with Hybrid Organic Additive
Technology (HOAT) engine coolant (anti -
freeze) or any “globally compatible” coolant
(antifreeze). If a non-OAT engine coolant
(antifreeze) is introduced into the cooling
system in an emergency, the cooling system will need to be drained, flushed, and refilled
with fresh OAT coolant (conforming to
MS.90032), by an authorized dealer as soon
as possible.
Do not use water alone or alcohol-based
engine coolant (antifreeze) products. Do not
use additional rust inhibitors or antirust prod
-
ucts, as they may not be compatible with the
radiator engine coolant and may plug the
radiator.
This vehicle has not been designed for use
with propylene glycol-based engine coolant
(antifreeze). Use of propylene glycol-based
engine coolant (antifreeze) is not recom -
mended.
Some vehicles require special tools to add
coolant properly. Failure to fill these systems
properly could lead to severe internal engine
damage. If any coolant is needed to be added
to the system please contact an authorized
dealer.
Adding Coolant
Your vehicle has been built with an improved
engine coolant (OAT coolant conforming to
MS.90032) that allows extended maintenance
intervals. This engine coolant (antifreeze) can

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