2020 Ram 1500 tire pressure

SERVICING AND MAINTENANCE 517
NOTE:
• P (Passenger) — Metric tire sizing is based on US designstandards. 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 designa
-
tion. 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 US design standards and it begins with the tire diameter molded into the side -
wall. 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 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)
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518 SERVICING AND MAINTENANCE
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 oper -
ating 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) EXAMPLE:
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SERVICING AND MAINTENANCE 519
Tire Identification Number (TIN)
The Tire Identification Number (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)
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Tire Terminology And DefinitionsABCD
= 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
Term Definition
B-Pillar The 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.EXAMPLE:
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SERVICING AND MAINTENANCE 521
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 recom-
mended pressure for your vehicle.
Example Tire Placard Location (Door)
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.
Term
Definition
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522 SERVICING AND MAINTENANCE
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 Information 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.
For further information on GAWRs, vehicle loading, and
trailer towing, refer to “Vehicle Loading” in the “Starting
And Operating” section of this manual.
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(Continued)
Tires — General Information
Tire Pressure
Proper tire inflation pressure is essential to the safe and satis-
factory 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 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 erraticand unpredictable steering response.
• Unequal tire pressure from side to side may cause the vehicle to drift left or right.
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 vehiclehandling 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.
WARNING! (Continued)
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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 replacement.
Ride Comfort And Vehicle Stability
Proper tire inflation contributes to a comfortable ride.
Over-inflation produces a jarring and uncomfortable ride.
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 qualitypocket-type pressure gauge. Do not make a visual judge -
ment 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 infla
-
tion 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 tempera -
ture 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. 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.
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