RAM 2500 Diesel (2007 year). Manual — part 21

WARNING!

Continued operation with reduced power steering
assist could pose a safety risk to yourself and others.
Service should be obtained as soon as possible.

CAUTION!

Prolonged operation of the steering system at the end
of the steering wheel travel will increase the steering
fluid temperature and should be avoided when pos-
sible. Damage to the power steering pump may occur.

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 designation. Ex-
ample: P215/65R15 95H.

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• 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.

• Temporary Spare tires are high-pressure compact

spares designed for temporary emergency use only.
Tires designed to this standard have the letter “T”
molded into the sidewall preceding the size designa-
tion. 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.

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Tire Sizing Chart

EXAMPLE:

Size Designation:

P

= Passenger car tire size based on U.S. design standards

ⴖ. blank. ⴖ = Passenger car tire based on European design standards
LT

= Light Truck tire based on U.S. design standards

T

= Temporary Spare tire

31

= Overall Diameter in Inches (in)

215

= Section Width in Millimeters (mm)

65

= Aspect Ratio in Percent (%)

—Ratio of section height to section width of tire.

10.5

= Section Width in Inches (in)

R

= Construction Code

—

⬙R⬙ means Radial Construction.

—

⬙D⬙ means Diagonal or Bias Construction.

15

= 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 certain operating conditions.
—The maximum speed corresponding to the Speed Symbol should only be achieved un-
der specified operating conditions (i.e. tire pressure, vehicle loading, road conditions, and
posted speed limits).

Load Identification:

ⴖ. blank. ⴖ = Absence of any text on sidewall of the tire indicates a Standard Load (SL) Tire
Extra Load (XL)

= Extra Load (or Reinforced) Tire

Light Load

= Light Load Tire

C,D,E

= 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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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 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.

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. (2 digits)

L9

= Code representing the tire size. (2 digits)

ABCD

= Code used by tire manufacturer. (1 to 4 digits)

03

= Number representing the week in which the tire was manufactured. (2 digits)

—03 means the 3rd week.

01

= Number representing the year in which the tire was manufactured. (2 digits)

—01 means the year 2001.
—Prior to July 2000, tire manufacturers were only required to have 1 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 Loading and Tire Pressure

Tire Placard Location

NOTE:

The proper cold tire inflation pressure is listed

on either the face of the driver’s door or the driver’s side
“B” pillar.

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) the total weight your vehicle can carry
3) the tire size designed for your vehicle
4) the cold tire inflation pressures for the front, rear,
and spare tires.

Tire Placard Location

Tire and Loading Information

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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” sec-
tion of this manual.

NOTE:

Under a maximum loaded vehicle condition,

gross axle weight ratings (GAWR’s) for the front and rear
axles must not be exceeded. For further information on
GAWR’s, vehicle loading, and trailer towing, refer to the
“Vehicle Loading” 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 occu-
pants and cargo should never exceed XXX pounds” 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 kilograms or XXX pounds.

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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. (since 5 x 150 = 750,
and 1400 – 750 = 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 available
cargo and luggage load capacity of your vehicle.

NOTE:

The following table shows examples on how to

calculate total load, cargo/luggage, and towing capaci-
ties 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.

NOTE:

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
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. Three primary
areas are affected by improper tire pressure:

1. Safety—

WARNING!

• Improperly inflated tires are dangerous and can cause acci-
dents.
• Under inflation increases tire flexing and can result in 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.
• Unequal tire pressures can cause steering problems. You
could lose control of your vehicle.
• Over inflated or under inflated tires can affect vehicle
handling and can fail suddenly, resulting in loss of vehicle
control.
• 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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2. Economy—
Improper inflation pressures can cause uneven wear pat-
terns to develop across the tire tread. These abnormal wear
patterns will reduce tread life resulting in a need for earlier
tire replacement. Under inflation, also increases tire rolling
resistance and results in higher fuel consumption.

3. 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 either on
the face of the driver’s door or on the driver’s side “B”
pillar.

Some vehicles may have Supplemental Tire Pressure
Information for vehicle loads that are less than the
maximum loaded vehicle condition. These pressure con-
ditions will be found in the “Supplemental Tire Pressure
Information” section of this manual.

The pressure should be checked and adjusted as well as
inspecting for signs of tire wear or visible damage at least
once a month. Use a good quality pocket-type gauge to
check tire pressure. Do not make a visual judgement
when determining proper inflation. Radial tires may look
properly inflated even when they are under inflated.

Tire Placard Location

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CAUTION!

After inspecting or adjusting the tire pressure, al-
ways reinstall the valve stem cap (if equipped). This
will prevent moisture and dirt from entering the
valve stem, which could damage the valve stem.

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 3 hours, or driven less than 1 mile
(1 km) after a 3 hour period. The cold tire inflation
pressure must not exceed the maximum inflation pres-
sure 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 pressure will be too low.

Tire Pressures for High Speed Operation
The manufacturer advocates driving at safe speeds
within posted speed limits. Where speed limits or condi-
tions are such that the vehicle can be driven at high
speeds, maintaining correct tire inflation pressure is very
important. Increased tire pressure and reduced vehicle

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loading may be required for high-speed vehicle opera-
tion. Refer to original equipment or an authorized tire
dealer for recommended safe operating speeds, loading
and cold tire inflation pressures.

WARNING!

High speed driving with your vehicle under maxi-
mum load is dangerous. The added strain on your
tires could cause them to fail. You could have a
serious accident. Don’t drive a vehicle loaded to the
maximum capacity at continuous speeds above 75
mph (120 km/h).

Radial-Ply Tires

WARNING!

Combining radial ply tires with other types of tires
on your vehicle will cause your vehicle to handle
poorly. The instability could cause an accident. Al-
ways use radial ply tires in sets of four (or 6, in case
of trucks with dual rear wheels). Never combine
them with other types of tires.

Cuts and punctures in radial tires are repairable only in
the tread area because of sidewall flexing. Consult your
authorized tire dealer for radial tire repairs.

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Compact Spare Tire — If Equipped
The compact spare is for temporary emergency use with
radial tires. It is engineered to be used on your style
vehicle only. Since this tire has limited tread life, the
original tire should be repaired (or replaced) and rein-
stalled at the first opportunity.

WARNING!

Temporary use spare tires are for emergency use only.
With these tires, do not drive more than 50 mph (80
km/h). Temporary-use spare tires have limited tread
life. When the tread is worn to the tread wear
indicators, the temporary use spare tire needs to be
replaced. Be sure to follow the warnings, which
apply to your spare. Failure to do so could result in
spare tire failure and loss of vehicle control.

Do not install a wheel cover or attempt to mount a
conventional tire on the compact spare wheel, since the
wheel is designed specifically for the compact spare.

Do not install more than one compact spare tire/wheel
on the vehicle at any given time.

CAUTION!

Because of the reduced ground clearance, do not take
your vehicle through an automatic car wash with the
compact spare installed. Damage to the vehicle may
result.

Limited Use Spare — If Equipped
The limited use spare tire is for temporary emergency use
on your vehicle. This tire is identified by a limited use
spare tire warning label located on the limited use spare
tire and wheel assembly. This tire may look like the

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original equipped tire on the front or rear axle of your
vehicle, but it is not. Installation of this limited use spare
tire affects vehicle handling. Since it is not the same tire,
replace (or repair) the original tire and reinstall on the
vehicle at the first opportunity.

WARNING!

The limited use spare tires are for emergency use
only. Installation of this limited use spare tire affects
vehicle handling. With this tire, do not drive more
than 60 mph (100 km/h). Keep inflated to the cold tire
inflation pressure listed on either your tire placard or
limited use spare tire and wheel assembly. Replace
(or repair) the original tire at the first opportunity
and reinstall it on your vehicle. Failure to do so could
result in loss of vehicle control.

Tire Spinning
When stuck in mud, sand, snow, or ice conditions, do not
spin your vehicle’s wheels faster than 30 mph (48 km/h)
or for longer than 30 seconds continuously without
stopping when you are stuck.

Refer to “Freeing A Stuck Vehicle” in Section 6 of this
manual for additional information.

WARNING!

Fast spinning tires can be dangerous. Forces gener-
ated by excessive wheel speeds may cause tire dam-
age or failure. A tire could explode and injure some-
one. Do not spin your vehicle’s wheels faster than 30
mph (48 km/h) or for more than 30 seconds continu-
ously when you are stuck, and don’t let anyone near
a spinning wheel, no matter what the speed.

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Tread Wear Indicators
Tread wear indicators are in the original equipment tires
to help you in determining when your tires should be
replaced.

These indicators are molded into the bottom of the tread
grooves. They will appear as bands when the tread depth
becomes 1/16 inch (2 mm). When the tread is worn to the
tread wear indicators, the tire should be replaced.

Many states have laws requiring tire replacement at this
point.

Life of Tire
The service life of a tire is dependent upon varying
factors including but not limited to:

• Driving style
• Tire pressure
• Distance driven

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