tire pressure Ram 1500 2015 Owner's Guide

with a separate computer to modulate hydraulic pressure
to prevent wheel lockup and help avoid skidding on
slippery surfaces.
The system’s pump motor runs during an ABS stop to
provide regulated hydraulic pressure. The pump motor
makes a low humming noise during operation. This is
normal.
The ABS conducts a low-speed selftest at about 10 mph
(16 km/h). If you have your foot lightly on the brake
while this test is occurring, you may feel slight pedal
movement. The movement can be more apparent on ice
and snow. This is normal.
When you are in a severe braking condition involving
use of the ABS, you will experience some pedal drop as
the vehicle comes to a complete stop. This is the result of
the system reverting to the base brake system and is
normal.
Engagement of the ABS may be accompanied by a
pulsing sensation. You may also hear a clicking noise.
These occurrences are normal, and indicate that the
system is functioning.
WARNING!
•Pumping of the anti-lock brakes will diminish
their effectiveness and may lead to a collision.
Pumping makes the stopping distance longer. Just
press firmly on your brake pedal when you need to
slow down or stop.
•The Anti-Lock Brake System (ABS) cannot prevent
the natural laws of physics from acting on the
vehicle, nor can it increase braking or steering
efficiency beyond that afforded by the condition of
the vehicle brakes and tires or the traction afforded.
(Continued)
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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 Markings
NOTE:
•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#P#is 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.DOTSafetyStandardsCode (TIN)4—MaximumLoad
2—SizeDesignation 5—MaximumPressure3 — Service Description 6 — Treadwear, Traction andTemperature 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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EXAMPLE:
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)
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EXAMPLE:
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
Tire Identification Number (TIN)
The 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.
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Tire Terminology And Definitions
TermDefinition
B-PillarThe vehicle B-Pillar is the structural member of the body located
behind the front door.
Cold Tire Inflation PressureCold 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. Inflation pressure is measured in units of PSI (pounds per
square inch) or kPa (kilopascals).
Maximum Inflation PressureThe maximum inflation pressure is the maximum permissible
cold tire inflation pressure for this tire. The maximum inflation
pressure is molded into the sidewall.
Recommended Cold Tire Inflation
Pressure
Vehicle manufacturer’s recommended cold tire inflation pressure
as shown on the tire placard.
Tire PlacardA label permanently attached to the vehicle describing the vehi-
cle’s loading capacity, the original equipment tire sizes and the
recommended cold tire inflation pressures.
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Tire Loading And Tire Pressure
Tire And Loading Information Placard Location
NOTE:The proper cold tire inflation pressure is listed on
the driver ’s side B-Pillar or the rear edge of the driver’s
side door.
Example Tire Placard Location (Door)
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3. Tire size designed for your vehicle.
4. Cold tire inflation pressures for the front, rear, and
spare tires.
Loading
The vehicle maximum load on the tire must not exceed
the load carrying capacity of the tire on your vehicle. You
will not exceed the tire’s load carrying capacity if you
adhere to the loading conditions, tire size, and cold tire
inflation pressures specified on the Tire and Loading
Information placard and in the “Vehicle Loading” section
of this manual.
NOTE:Under a maximum loaded vehicle condition,
gross axle weight ratings (GAWRs) for the front and rear
axles must not be exceeded. For further information on
GAWRs, vehicle loading, and trailer towing, refer to
“Vehicle Loading” in this section.
To determine the maximum loading conditions of your
vehicle, locate the statement “The combined weight of
occupants and cargo should never exceed XXX lbs or
XXX kg” on the Tire and Loading Information placard.
The combined weight of occupants, cargo/luggage and
trailer tongue weight (if applicable) should never exceed
the weight referenced here.
Steps For Determining Correct Load Limit
1. Locate the statement “The combined weight of occu-
pants and cargo should never exceed XXX lbs or
XXX kg” on your vehicle’s placard.
2. Determine the combined weight of the driver and
passengers that will be riding in your vehicle.
3. Subtract the combined weight of the driver and pas-
sengers from XXX lbs or XXX kg.
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WARNING!
Overloading of your tires is dangerous. Overloading
can cause tire failure, affect vehicle handling, and
increase your stopping distance. Use tires of the
recommended load capacity for your vehicle. Never
overload them.
TIRES — GENERAL INFORMATION
Tire Pressure
Proper tire inflation pressure is essential to the safe and
satisfactory operation of your vehicle. Four primary areas
are affected by improper tire pressure:
•Safety and Vehicle Stability
•Economy
•Tread Wear
•Ride Comfort
Safety
WARNING!
•Improperly inflated tires are dangerous and can
cause collisions.
•Under-inflation increases tire flexing and can re-
sult in overheating and tire failure.
•Over-inflation reduces a tire’s ability to cushion
shock. Objects on the road and chuckholes can
cause damage that result in tire failure.
•Overinflated or under-inflated tires can affect ve-
hicle handling and can fail suddenly, resulting in
loss of vehicle control.
•Unequal tire pressures can cause steering prob-
lems. You could lose control of your vehicle.
(Continued)
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