2019 Ram 3500 tire size

STARTING AND OPERATING 315
The “Transfer Case Position Indicator Light” in the instru-
ment cluster will alert the driver that the vehicle is in
four-wheel drive and that the front and rear driveshafts are
locked together. This light will illuminate when the transfer
case is shifted into either the 4H or 4L position. There is no
light for the 2H or NEUTRAL positions on some models.
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 four-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 drivetrain.
NOTE:
Do not attempt to make a shift while only the front or rear
wheels are spinning, as this can cause damage to driveline
components.
Because four-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, exces
-
sive vehicle loading, or cold temperatures.
Two-Wheel Drive High Range (2H)
Rear-Wheel Drive High Range — This range is for normal
street and highway driving on dry hard surfaced roads.
Four-Wheel Drive High Range (4H)
Four-Wheel Drive High Range — This range locks the front
and rear driveshafts together forcing the front and rear
wheels to rotate at the same speed. Additional traction for
loose, slippery road surfaces only.
WARNING!
You or others could be injured or killed if you leave the
vehicle unattended with the transfer case in the
NEUTRAL position without first fully engaging the
parking brake. The transfer case NEUTRAL position
disengages both the front and rear drive shafts from the
powertrain and will allow the vehicle to roll, even if the
transmission is in PARK. The parking brake should
always be applied when the driver is not in the vehicle.
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STARTING AND OPERATING 359
Adaptive Cruise Control (ACC) Operation
The speed control buttons (located on the right side of the
steering wheel) operate the ACC system.Adaptive Cruise Control Buttons
NOTE:
Any chassis/suspension or tire size modifications to the
vehicle will effect the performance of the Adaptive Cruise
Control and Forward Collision Warning System.
• Will bring the vehicle to a complete stop while
following a target vehicle and hold the vehicle for
approximately two seconds in the stop position. At
this point, there will be an “ACC may cancel soon”
chime and warning to the driver. When ACC is
cancelled, the system will release the brakes and the
driver must take over braking. The system can be
resumed when the target vehicle drives off by
releasing the brake and pushing the resume button
on the steering wheel.
You should switch off the ACC system:
• When driving in fog, heavy rain, heavy snow, sleet, heavy traffic, and complex driving situations (i.e., in
highway construction zones).
• When entering a turn lane or highway off ramp; when driving on roads that are winding, icy, snow-covered,
slippery, or have steep uphill or downhill slopes.
• When towing a trailer up or down steep slopes.
• When circumstances do not allow safe driving at a constant speed.
WARNING! (Continued)
1 — Adaptive Cruise Control On/Off Button
2 — Distance Button
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410 STARTING AND OPERATING
Loose Fuel Filler Cap Message
If the vehicle diagnostic system determines that the
fuel filler cap is loose, improperly installed, or
damaged, a loose gascap indicator will display in the
instrument cluster telltale display area. Refer to “Instrument
Cluster Display” in “Getting To Know Your Instrument
Panel” for further information. Tighten the fuel filler cap
properly and push the RIGHT button to turn off the message.
If the problem continues, the message will appear the next
time the vehicle is started.
VEHICLE LOADING
Gross Vehicle Weight Rating (GVWR)
The GVWR is the total permissible weight of your vehicle
including driver, passengers, vehicle, options and cargo. The
label also specifies maximum capacities of front and rear axle
systems (GAWR). Total load must be limited so GVWR and
front and rear GAWR are not exceeded.
Payload
The payload of a vehicle is defined as the allowable load
weight a truck can carry, including the weight of the driver,
all passengers, options and cargo.
Gross Axle Weight Rating (GAWR)
The GAWR is the maximum permissible load on the front
and rear axles. The load must be distributed in the cargo area
so that the GAWR of each axle is not exceeded.
Each axle GAWR is determined by the components in the
system with the lowest load carrying capacity (axle, springs,
tires or wheels). Heavier axles or suspension components
sometimes specified by purchasers for increased durability
does not necessarily increase the vehicle's GVWR.
Tire Size
The tire size on the Vehicle Certification Label represents the
actual tire size on your vehicle. Replacement tires must be
equal to the load capacity of this tire size.
Rim Size
This is the rim size that is appropriate for the tire size listed.
Inflation Pressure
This is the cold tire inflation pressure for your vehicle for all
loading conditions up to full GAWR.

420 STARTING AND OPERATING
Towing Requirements — Tires
• Do not attempt to tow a trailer while using a compact sparetire.
• Do not drive more than 50 mph (80 km/h) when towing while using a full size spare tire.
• Proper tire inflation pressures are essential to the safe and satisfactory operation of your vehicle. Refer to “Tires” in
“Servicing And Maintenance” for proper tire inflation
procedures.
• Check the trailer tires for proper tire inflation pressures before trailer usage.
• Check for signs of tire wear or visible tire damage before towing a trailer. Refer to “Tires” in “Servicing And Main -
tenance” for the proper inspection procedure.
• When replacing tires, refer to “Tires” in “Servicing And Maintenance” for the proper tire replacement procedures.
Replacing tires with a higher load carrying capacity will
not increase the vehicle's GVWR and GAWR limits. Towing Requirements — Trailer Brakes
• Do
not interconnect the hydraulic brake system or vacuum
system of your vehicle with that of the trailer. This could
cause inadequate braking and possible personal injury.
• An electronically actuated trailer brake controller is required when towing a trailer with electronically actu -
ated brakes. When towing a trailer equipped with a
hydraulic surge actuated brake system, an electronic brake
controller is not required.

• Trailer brakes are recommended for trailers over 1,000 lbs (453 kg) and required for trailers in excess of 2,000 lbs (907 kg).

WARNING!
• Do not connect trailer brakes to your vehicle's hydraulic brake lines. It can overload your brake
system and cause it to fail. You might not have brakes
when you need them and could have an accident.
• Towing any trailer will increase your stopping distance. When towing, you should allow for addi -
tional space between your vehicle and the vehicle in
front of you. Failure to do so could result in an accident.

SERVICING AND MAINTENANCE 531
HOISTING
A conventional floor jack may be used at the jacking loca-
tions. Refer to the graphics that show jacking locations.
However, a floor jack or frame hoist must never be used on
any other parts of the underbody.
TIRES
Tire Safety Information
Tire safety information will cover aspects of the following
information: Tire Markings, Tire Identification Numbers,
Tire Terminology and Definitions, Tire Pressures, and Tire
Loading. Tire Markings
Tire Markings
CAUTION!
Never use a floor jack directly under the differential
housing of a loaded truck or damage to your vehicle may
result.
1 — U.S. DOT Safety
Standards Code (TIN) 4 — Maximum Load
2 — Size Designation 5 — Maximum Pressure
3 — Service Description 6 — Treadwear, Traction and Temperature Grades7

532 SERVICING AND MAINTENANCE
NOTE:
• P (Passenger) — Metric tire sizing is based on U.S. 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 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 desig -
nation. 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 U.S. design standards and it begins with the tire diameter molded into the side -
wall. Example: 31x10.5 R15 LT.

SERVICING AND MAINTENANCE 533
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
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
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SERVICING AND MAINTENANCE 535
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 side-
walls 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.
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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