2007 RAM CHASSIS CAB tire size

The 4-wheel-drive light (4WD), located in the instrument
cluster, alerts the driver that the vehicle is in 4-wheel
drive and that the front and rear driveshafts are locked
together. This light illuminates when the transfer case is
shifted to either the 4H or 4L positions. There is no light
for the 2H or N (Neutral) positions.
When operating your vehicle in 4L, the engine speed is
approximately three times that of the 2H or 4H positions
at a given road speed. Take care not to overspeed the
engine and do not exceed 25 mph (40 km/h).
Proper operation of 4-wheel-drive vehicles depends on
tires of equal size, type and circumference on each wheel.
Any difference will adversely affect shifting and can
cause damage to the transfer case. NOTE: Do not attempt to make a shift while only the
front or rear wheels are spinning. The transfer case is not
equipped with a synchronizer and therefore the front and
rear driveshaft speeds must be equal for the shift to take
place. Shifting while only the front or rear wheels are
spinning can cause damage to the transfer case.
Because 4-wheel drive provides improved traction, there
is a tendency to exceed safe turning and stopping speeds.
Do not go faster than road conditions permit.
NOTE: Delayed shifts out of four-wheel drive may be
experienced due to uneven tire wear, low or uneven tire
pressures, excessive vehicle loading, or cold tempera-
tures.284 STARTING AND OPERATING

Proper operation of 4 wheel drive vehicles depends on
tires of equal size, type and circumference on each wheel.
Any difference in tire size can cause damage to the
transfer case.
Because 4 wheel drive provides improved traction, there
is a tendency to exceed safe turning and stopping speeds.
Do not go faster than road conditions permit. WARNING!You or others could be injured if you leave the
vehicle unattended with the transfer case in the
Neutral (N) position without first fully engaging the
parking brake. The transfer case Neutral (N) position
disengages both the front and rear driveshafts from
the powertrain and will allow the vehicle to move
regardless of the transmission position. The parking
brake should always be applied when the driver is
not in the vehicle.
For additional information on the appropriate use of each
transfer case mode position see the information below:
2WD
Rear Wheel Drive High Range - Normal street and
highway driving. Dry hard surfaced roads. STARTING AND OPERATING 291
5

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 possible. 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. STARTING AND OPERATING 305
5

• 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.
Tire Sizing Chart
EXAMPLE:
Size Designation:
P = Passenger car tire size based on U.S. design standards
 ....blank....  = Passenger car tire based on European design standards
LT = Light Truck tire based on U.S. design standards
T = Temporary Spare tire306 STARTING AND OPERATING

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. STARTING AND OPERATING 309
5

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.
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. STARTING AND OPERATING 311
5

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
WARNING!Tires and spare tire should be replaced after six
years, regardless of the remaining tread. Failure to
follow this warning can result in sudden tire failure.
You could lose control and have an accident result-
ing in serious injury or death. Keep dismounted tires in a cool, dry place with as little
exposure to light as possible. Protect tires from contact
with oil, grease, and gasoline.
Replacement Tires
The tires on your new vehicle provide a balance of many
characteristics. They should be inspected regularly for
wear and correct cold tire inflation pressure. The manu-
facturer strongly recommends that you use tires equiva-
lent to the originals in size, quality and performance
when replacement is needed (refer to the paragraph on
“Tread Wear Indicators”). Refer to the “Tire and Loading
Information” placard for the size designation of your tire.
The service description and load identification will be
found on the original equipment tire. Failure to use
equivalent replacement tires may adversely affect the
safety, handling, and ride of your vehicle. We recommend
that you contact your original equipment or an autho-
rized tire dealer with any questions you may have on tire
specifications or capability. STARTING AND OPERATING 321
5

WARNING!• Do not use a tire, wheel size or rating other than
that specified for your vehicle. Some combina-
tions of unapproved tires and wheels may
change suspension dimensions and performance
characteristics, resulting in changes to steering,
handling, and braking of your vehicle. This can
cause unpredictable handling and stress to steer-
ing and suspension components. You could lose
control and have an accident resulting in serious
injury or death. Use only the tire and wheel sizes
with load ratings approved for your vehicle.
• Never use a tire with a smaller load index or
capacity, other than what was originally
equipped on your vehicle. Using a tire with a
smaller load index could result in tire overload-
ing and failure. You could lose control and have
an accident.
• Failure to equip your vehicle with tires having
adequate speed capability can result in sudden
tire failure and loss of vehicle control. CAUTION!Replacing original tires with tires of a different size
may result in false speedometer and odometer read-
ings.
Alignment And Balance
Poor suspension alignment may result in:
• Fast tire wear.
• Uneven tire wear, such as feathering and one-sided
wear.
• Vehicle pull to right or left.
Tires may also cause the vehicle to pull to the left or right.
Alignment will not correct this condition. See your dealer
for proper diagnosis.322 STARTING AND OPERATING