Ram 3500 2018 Owner's Manual

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 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 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 preceding the
size designation. Example: LT235/85R16. •
Temporary spare tires are designed for temporary emer-
gency 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 U.S. design stan-
dards and it begins with the tire diameter molded into
the sidewall. Example: 31x10.5 R15 LT.
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SERVICING AND MAINTENANCE 559

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)
R = Construction code
–R means radial construction, or
–D means diagonal or bias construction
15, 16, 18 = Rim diameter in inches (in)
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EXAMPLE:
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 cer-
tain operating conditions
–The maximum speed corresponding to the speed symbol should only be achieved under specified operating condi-
tions (i.e., tire pressure, vehicle loading, road conditions, and posted speed limits)
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
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SERVICING AND MAINTENANCE 561

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 forthe 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.
EXAMPLE:
DOT MA L9 ABCD 0301
DOT = Department of Transportation
–This symbol certifies that the tire is in compliance with the U.S. 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
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
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Tire Terminology And Definitions
TermDefinition
B-Pillar The vehicle B-Pillar is the structural member of the body located be-
hind 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. In-
flation 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 recom-
mended cold tire inflation pressures.
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SERVICING AND MAINTENANCE 563

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 pressure for your vehicle.
Example Tire Placard Location (Door)
Example Tire Placard Location (B-Pillar)
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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 sparetires.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 in “Vehicle Loading” in the “Starting And Operat-
ing” 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 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.
Tire And Loading Information Placard
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SERVICING AND MAINTENANCE 565

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 available 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. Consultthis manual to determine how this reduces the available
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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WARNING!
Overloading of your tires is dangerous. Overloading
can cause tire failure, affect vehicle handling, and
increase your stopping distance. Use tires of the rec-
ommended load capacity for your vehicle. Never over-
load them.
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SERVICING AND MAINTENANCE 567

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.
• 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.
(Continued)
WARNING! (Continued)
•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 recom-
mended cold tire inflation pressure.
Both under-inflation and over-inflation 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.
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