2020 RAM CHASSIS CAB Owners Manual

SERVICING AND MAINTENANCE375
Tire Markings

Tire Markings

NOTE:
P (Passenger) — Metric tire sizing is based on
US design standards. P-Metric tires have the
letter “P” molded into the sidewall preceding
the size designation.
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 US 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 preceding the size
designation.
Example: LT235/85R16.
Temporary spare tires are designed for
temporary emergency use only. Temporary
high pressure compact 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 US
design standards and it begins with the tire
diameter molded into the sidewall.
Example: 31x10.5 R15 LT.
1 — US DOT Safety Standards Code
(TIN)
2 — Size Designation
3 — Service Description
4 — Maximum Load
5 — Maximum Pressure
6 — Treadwear, Traction and Tempera -
ture Grades
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376SERVICING AND MAINTENANCE
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 US design standards, or
"....blank...." = Passenger car tire based on European design standards, or
LT = Light truck tire based on US design standards, or
T or S = 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)
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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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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380SERVICING AND MAINTENANCE
For further information on GAWRs, vehicle
loading, and trailer towing, refer to “Vehicle
Loading” in the “Starting And Operating”
section of this manual.
To determine the maximum loading conditions
of your vehicle, locate the statement “The
combined weight of occupants and cargo
should never exceed XXX kg or XXX lbs” 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 occupants and cargo should
never exceed XXX kg or XXX lbs.” 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 passengers from XXX kg or
XXX lbs. (4) The resulting figure equals the avail
-
able amount of cargo and luggage load
capacity. For example, if “XXX” amount
equals 1400 lbs. and there will be five
150 lb passengers in your vehicle, the
amount of available cargo and luggage
load capacity is 650 lbs. (1400-750
(5x150) = 650 lbs.)
(5) Determine the combined weight of
luggage and cargo being loaded on the
vehicle. That weight may not safely
exceed the available cargo and luggage
load capacity calculated in Step 4.
(6) If your vehicle will be towing a trailer,
load from your trailer will be transferred
to your vehicle. Consult this manual to
determine how this reduces the avail -
able cargo and luggage load capacity of
your vehicle.
Metric Example For Load Limit
For example, if “XXX” amount equals 635 kg
and there will be five 68 kg passengers in your
vehicle, the amount of available cargo and
luggage load capacity is 295 kg (635-340
(5x68) = 295 kg) as shown in step 4.
NOTE:
If your vehicle will be towing a trailer, load
from your trailer will be transferred to your
vehicle. The following table shows examples
on how to calculate total load, cargo/
luggage, and towing capacities of your
vehicle with varying seating configurations
and number and size of occupants. This table
is for illustration purposes only and may not
be accurate for the seating and load carry
capacity of your vehicle.
For the following example, the combined
weight of occupants and cargo should never
exceed 865 lbs (392 kg).

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SERVICING AND MAINTENANCE381
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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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