2020 Ram 4500 Chassis Cab inflation pressure

STARTING AND OPERATING273
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 allow -
able 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 compo -
nents in the system with the lowest load
carrying capacity (axle, springs, tires or wheels).
Heavier axles or suspension components some -times 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 condi
-
tions, 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.
The entire vehicle should first be weighed on a
commercial scale to ensure that the GVWR has
not been exceeded. The weight on the front and
rear of the vehicle should then be determined
separately to be sure that the load is properly
distributed over the front and rear axles.
Weighing the vehicle may show that the GAWR
of either the front or rear axle has been
exceeded but the total load is within the speci -
fied GVWR. If so, weight must be shifted from
front to rear or rear to front as appropriate until
the specified weight limitations are met. Store
the heavier items down low and be sure that the
weight is distributed equally. Stow all loose
items securely before driving.
Improper weight distributions can have an
adverse effect on the way your vehicle steers
and handles and the way the brakes operate.
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280STARTING AND OPERATING
(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.
WARNING!
Make certain that the load is secured in the
trailer and will not shift during travel. When
trailering cargo that is not fully secured,
dynamic load shifts can occur that may be
difficult for the driver to control. You could
lose control of your vehicle and have a colli -
sion.
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.
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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329
SERVICING AND MAINTENANCE
SCHEDULED SERVICING — GAS ENGINE
Your vehicle is equipped with an automatic oil
change indicator system. The oil change indi-
cator 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 Condi-
tions can cause the change oil message to illu -
minate 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 sched
-
uled oil change. If a scheduled oil change is
performed by someone other than an autho -
rized dealer, the message can be reset by refer -
ring to the steps described under “Instrument
Cluster Display” in “Getting To Know Your
Instrument Panel” for further information.
Gas Engines:
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:
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 predominately at idle or very low
engine RPM. This type of vehicle use is consid -
ered Severe Duty. Once A Month Or Before A Long Trip:Check engine oil level.
Check windshield washer fluid level.
Check the tire inflation pressures and look
for unusual wear or damage. Rotate at the
first sign of irregular wear.
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
lights.
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SERVICING AND MAINTENANCE377
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.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
EXAMPLE:
EXAMPLE:
DOT MA L9 ABCD 0301
DOT = Department of Transportation
This symbol certifies that the tire is in compliance with the US Department of Transportation tire safety standards and is approved for highway use
MA = Code representing the tire manufacturing location (two digits)
L9 = Code representing the tire size (two digits)
ABCD = Code used by the tire manufacturer (one to four digits)
03 = Number representing the week in which the tire was manufactured (two digits)
03 means the 3rd week
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378SERVICING AND MAINTENANCE
Tire Terminology And Definitions
01 = Number representing the year in which the tire was manufactured (two digits)
01 means the year 2001
Prior to July 2000, tire manufacturers were only required to have one number to represent the year in which the tire was manufactured. Example:
031 could represent the 3rd week of 1981 or 1991
Term Definition
B-PillarThe vehicle B-Pillar is the structural member of the body located behind the front door.
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. Inflation pressure is measured in units of PSI (pounds per
square inch) or kPa (kilopascals).
Maximum Inflation Pressure The 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 Placard A label permanently attached to the vehicle describing the vehicle’s loading capacity,
the original equipment tire sizes and the recommended cold tire inflation pressures.
EXAMPLE:

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SERVICING AND MAINTENANCE379
Tire Loading And Tire Pressure
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.
Check the inflation pressure of each tire,
including the spare tire (if equipped), at least
monthly and inflate to the recommended pres -
sure for your vehicle.

Example Tire Placard Location (Door) Example Tire Placard Location (B-Pillar)

Tire And Loading Information Placard

Tire And Loading Information Placard
This placard tells you important information
about the:

1. Number of people that can be carried in
the vehicle.

2. Total weight your vehicle can carry.
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 pres -
sures specified on the Tire and Loading Infor -
mation placard in “Vehicle Loading” in the
“Starting And Operating” 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.
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382SERVICING AND MAINTENANCE
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
Fuel Economy
Tread Wear
Ride Comfort and Vehicle Stability Safety
Both underinflation and overinflation affect the
stability of the vehicle and can produce a feeling
of sluggish response or over responsiveness in
the steering.
NOTE:
Unequal tire pressures from side to side may
cause erratic and unpredictable steering
response.
Unequal tire pressure from side to side may
cause the vehicle to drift left or right.
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 replace -
ment.
Ride Comfort And Vehicle Stability
Proper tire inflation contributes to a comfort -
able ride. Overinflation produces a jarring and
uncomfortable ride.
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.WARNING!
Improperly inflated tires are dangerous and
can cause collisions.
Underinflation increases tire flexing and
can result in overheating and tire failure.
Overinflation reduces a tire's ability to
cushion shock. Objects on the road and
chuckholes can cause damage that result
in tire failure.
Overinflated or underinflated tires can
affect vehicle handling and can fail
suddenly, resulting in loss of vehicle
control.
Unequal tire pressures can cause steering
problems. You could lose control of your
vehicle.
Unequal tire pressures from one side of the
vehicle to the other can cause the vehicle
to drift to the right or left.
Always drive with each tire inflated to the
recommended cold tire inflation pressure.

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SERVICING AND MAINTENANCE383
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 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.
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 sidewall.
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 pres
-
sure 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 authorized tire
dealer or original equipment vehicle dealer for
recommended safe operating speeds, loading
and cold tire inflation pressures.
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.
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).
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