2015 Ram 3500 tire pressure

CAUTION!
On icy or slippery roads, do not downshift at high
engine RPMs or vehicle speeds because engine brak-
ing may cause skidding and loss of control.
• Mud – Deep mud creates a great deal of suction
around the tires and is very difficult to get through.
You should use 4L (Low Range) with a gear low
enough to maintain your momentum without shifting.
If you start to slow to a stop, try turning your steering
wheel no more than a ¼ turn quickly back and forth
for additional traction. Mud holes pose an increased
threat of vehicle damage and getting stuck. 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 using the appro-
priate tire pressure, accelerating slowly, avoiding
abrupt maneuvers and maintaining the vehicle’s mo-
mentum. 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 drastically
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.
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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.
Crossing Obstacles (Rocks And Other 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 thethrottle lightly while holding a light brake pressure and
ease the vehicle up and over the object.
WARNING!
Crossing obstacles can cause abrupt steering system
loading which could cause you to loose control of
your vehicle.
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.
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the water is deep enough to push on the large surface
area of the vehicle’s body. Before you proceed determine
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.
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.
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 itssurface 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 sur-
faces 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 so,
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!
Reduced tire pressure increases the risk of tire dam-
age 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.
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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 diago-
nally 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.
After Driving Off-Road
Off-road operation puts more stress on your vehicle than
does most on-road driving. After going off-road, it isalways a good idea to check for damage. That way you
can get any problems taken care of right away and have
your vehicle ready when you need it.
•
Completely inspect the underbody of your vehicle.
Check tires, body structure, steering, suspension, and
exhaust system for damage.
• Inspect the radiator for mud and debris and clean as
required.
• Check threaded fasteners for looseness, particularly on
the chassis, drivetrain components, steering, and sus-
pension. Retighten them, if required, and torque to the
values specified in the Service Manual.
• Check for accumulations of plants or brush. These
things could be a fire hazard. They might hide damage
to fuel lines, brake hoses, axle pinion seals, and
propeller shafts.
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WARNING!(Continued)
efficiency beyond that afforded by the condition of
the vehicle brakes and tires or the traction afforded.
• The ABS cannot prevent collisions, including those
resulting from excessive speed in turns, following
another vehicle too closely, or hydroplaning.
• The capabilities of an ABS-equipped vehicle must
never be exploited in a reckless or dangerous
manner which could jeopardize the user’s safety or
the safety of others.
ABS Warning Light
The ABS includes an amber warning light. When the light
is illuminated, the ABS is not functioning. The system
reverts to standard, non-anti-lock brakes.
Traction Control System (TCS)
The TCS monitors the amount of wheel spin of each of
the driven wheels. If wheel spin is detected, brake pressure is applied to the slipping wheel(s), and engine
power is reduced to provide enhanced acceleration and
stability. A feature of the TCS system, Brake Limited
Differential (BLD), controls the wheel spin across a
driven axle. If one wheel on a driven axle is spinning
faster than the other, the system will apply the brake of
the spinning wheel. This will allow more engine torque
to be applied to the wheel that is not spinning. This
feature remains active even if TCS and ESC are in the
“Partial Off” mode. Refer to “Electronic Stability Control
(ESC)” in this section of this manual. This brake pressure
modulation transfers drive torque from slipping to non-
slipping wheels to provide optimal forward traction.
Brake Assist System (BAS)
The BAS is designed to optimize the vehicle’s braking
capability during emergency braking maneuvers. The
BAS detects an emergency braking situation by sensing
the rate and amount of brake application and then
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applies optimum pressure to the brakes. The system
applies optimum pressure to the brakes in emergency
braking conditions. This can help reduce braking dis-
tances. The BAS complements the ABS. Applying the
brakes very quickly results in the best BAS assistance. To
receive the benefit of BAS, you must apply continuous
braking pressure during the stopping sequence. Do not
reduce brake pedal pressure unless braking is no longer
desired.
Once the brake pedal is released, the BAS is deactivated.
WARNING!
•The BAS cannot prevent the natural laws of phys-
ics from acting on the vehicle, nor can it increase
braking efficiency beyond that afforded by the
condition of the vehicle brakes and tires or the
traction afforded.
(Continued)
WARNING! (Continued)
•The BAS cannot prevent collisions, including those
resulting from excessive speed in turns, following
another vehicle too closely, or hydroplaning.
• The capabilities of a BAS-equipped vehicle must
never be exploited in a reckless or dangerous
manner which could jeopardize the user ’s safety or
the safety of others.
Hill Start Assist (HSA)
The HSA system is designed to assist the driver in
launching a vehicle on an incline. HSA will maintain the
level of brake pressure the driver inputs for a short
duration once the driver takes his foot off of the brake
pedal. If the driver does not apply the throttle during this
short duration, the system will release brake pressure
and the vehicle will roll down the incline. The system will
release brake pressure in proportion to the amount of
throttle applied.
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TIRE SAFETY INFORMATION
Tire MarkingsNOTE:
•P (Passenger) — Metric tire sizing is based on U.S.
design standards. P-Metric tires have the letter “P”
molded into the sidewall preceding the size designa-
tion. 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 Pis absent from this tire
size designation. Example: 215/65R15 96H.
• LT (Light Truck) — Metric tire sizing is based on U.S.
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 preced-
ing the size designation. Example: LT235/85R16.
1 — U.S. DOT Safety Standards
Code (TIN) 4 — Maximum Load
2 — Size Designation 5 — Maximum Pressure
3 — Service Description 6 — Treadwear, Traction and Temperature Grades
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•Temporary spare tires are designed for temporary
emergency use only. Temporary high pressure com-
pact 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 U.S. design
standards and it begins with the tire diameter molded
into the sidewall. Example: 31x10.5 R15 LT.
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 U.S. design standards, or
....blank.... = Passenger car tire based on European design standards, or
LT = Light truck tire based on U.S. design standards, or
TorS= 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)
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