2019 RAM CHASSIS CAB wheel size

338 STARTING AND OPERATING
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.
Curb Weight
The curb weight of a vehicle is defined as the total weight of
the vehicle with all fluids, including vehicle fuel, at full
capacity conditions, and with no occupants or cargo loaded
into the vehicle. The front and rear curb weight values are
determined by weighing your vehicle on a commercial scale
before any occupants or cargo are added.
Loading
The actual total weight and the weight of the front and rear
of your vehicle at the ground can best be determined by
weighing it when it is loaded and ready for operation.
The entire vehicle should first be weighed on a commercial
scale to insure that the GVWR has not been exceeded. The
weight on the front and rear of the vehicle should then be
determined separately to be sure that the load is properly
distributed over the front and rear axle. Weighing the vehicle
may show that the GAWR of either the front or rear axles has
been exceeded but the total load is within the specified
GVWR. If so, weight must be shifted from front to rear or

STARTING AND OPERATING 347
(Continued) Towing Requirements — Tires
• Do not attempt to tow a trailer while using a compact spare
tire.
• Do not drive more than 50 mph (80 km/h) when towing
while using a full size spare tire.WARNING!
• Make certain that the load is secured in the trailer and
will not shift during travel. When trailering cargo that
is not fully secured, dynamic load shifts can occur that
may be difficult for the driver to control. You could lose
control of your vehicle and have a collision.
• When hauling cargo or towing a trailer, do not overload
your vehicle or trailer. Overloading can cause a loss of
control, poor performance or damage to brakes, axle,
engine, transmission, steering, suspension, chassis
structure or tires.
• Safety chains must always be used between your
vehicle and trailer. Always connect the chains to the
hook retainers of the vehicle hitch. Cross the chains
under the trailer tongue and allow enough slack for
turning corners.
• Vehicles with trailers should not be parked on a grade.
When parking, apply the parking brake on the tow
vehicle. Put the tow vehicle transmission in PARK. For
four-wheel drive vehicles, make sure the transfer case
is not in NEUTRAL. Always, block or "chock" the
trailer wheels.
• GCWR must not be exceeded. • Total weight must be distributed between the tow
vehicle and the trailer such that the following four
ratings are not exceeded:
• GVWR
• GTW
• GAWR
• Tongue weight rating for the trailer hitch utilized. WARNING! (Continued)
5

374 IN CASE OF EMERGENCY
(Continued)4. Reach through the access hole of the wheel house splash
shield and disengage the bulb access cover by rotating
counterclockwise.
Bulb Access Cover
5. Disconnect the internal lamp wiring harness connector
from the low beam bulb. 6. Rotate the bulb counterclockwise 1/4 turn to unlock the
bulb from the lamp.
7. Pull the bulb straight out from the housing.
8. Reverse the procedure for installation of new bulb and
covers.
High Beam
1. Open the hood.
2. Disconnect and isolate the negative battery cable.
3. Look under the hood and behind the headlamp to find
the high beam bulb access cover.
4. Reach behind the headlamp and disengage the access
cover by rotating counterclockwise.
5. Disconnect the internal lamp wiring harness connector
from the high beam bulb.CAUTION!
• Do not contaminate the bulb glass by touching it with
your fingers or by allowing it to contact other oily
surfaces. Shortened bulb life will result. • Always use the correct bulb size and type for replace -
ment. An incorrect bulb size or type may overheat and
cause damage to the lamp, the bulb socket, or the lamp
wiring. CAUTION! (Continued)

SERVICING AND MAINTENANCE 459
(Continued)NOTE:
Wheel Valve Stem must be replaced as well when installing
new tires due to wear and tear in existing tires.
Keep dismounted tires in a cool, dry place with as little expo -
sure 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 pressures. The manufacturer
strongly recommends that you use tires equivalent to the
originals in size, quality and performance when replacement
is needed. Refer to the paragraph on “Tread Wear Indica -
tors” in this section. Refer to the Tire and Loading Informa -
tion placard or the Vehicle Certification Label for the size
designation of your tire. The Load Index and Speed Symbol
for your tire will be found on the original equipment tire
sidewall.
See the Tire Sizing Chart example found in the “Tire Safety
Information” section of this manual for more information
relating to the Load Index and Speed Symbol of a tire. It is recommended to replace the two front tires or two rear
tires as a pair. Replacing just one tire can seriously affect
your vehicle’s handling. If you ever replace a wheel, make
sure that the wheel’s specifications match those of the orig -
inal wheels.
It is recommended you contact an authorized tire dealer or
original equipment dealer with any questions you may have
on tire specifications or capability. Failure to use equivalent
replacement tires may adversely affect the safety, handling,
and ride of your vehicle.
WARNING!
• Do not use a tire, wheel size, load rating, or speed rating
other than that specified for your vehicle. Some combi -
nations of unapproved tires and wheels may change
suspension dimensions and performance characteris -
tics, resulting in changes to steering, handling, and
braking of your vehicle. This can cause unpredictable
handling and stress to steering and suspension compo -
nents. You could lose control and have a collision
resulting in serious injury or death. Use only the tire
and wheel sizes with load ratings approved for your
vehicle. 7

SERVICING AND MAINTENANCE 461
Snow Tires
Some areas of the country require the use of snow tires
during the Winter. Snow tires can be identified by a “moun -
tain/snowflake” symbol on the tire sidewall.
If you need snow tires, select tires equivalent in size
and type to the original equipment tires. Use snow
tires only in sets of four; failure to do so may
adversely affect the safety and handling of your vehicle.
Snow tires generally have lower speed ratings than what was
originally equipped with your vehicle and should not be
operated at sustained speeds over 75 mph (120 km/h). For
speeds above 75 mph (120 km/h) refer to original equipment
or an authorized tire dealer for recommended safe operating
speeds, loading and cold tire inflation pressures.
While studded tires improve performance on ice, skid and
traction capability on wet or dry surfaces may be poorer than
that of non-studded tires. Some states prohibit studded tires;
therefore, local laws should be checked before using these
tire types. Spare Tires — If Equipped
NOTE:
For vehicles equipped with Tire Service Kit instead of a spare
tire, please refer to “Tire Service Kit” in “In Case Of Emer -
gency” for further information.
Refer to the “Towing Requirements - Tires” in “Starting And
Operating” for restrictions when towing with a spare tire
designated for temporary emergency use.
Spare Tire Matching Original Equipped Tire And Wheel
— If Equipped
Your vehicle may be equipped with a spare tire and wheel
equivalent in look and function to the original equipment
tire and wheel found on the front or rear axle of your vehicle.
This spare tire may be used in the tire rotation for your
vehicle. If your vehicle has this option, refer to an authorized
tire dealer for the recommended tire rotation pattern. CAUTION!
Because of the reduced ground clearance, do not take
your vehicle through an automatic car wash with a
compact or limited use temporary spare installed.
Damage to the vehicle may result.
7

462 SERVICING AND MAINTENANCE
Compact Spare Tire — If Equipped
The compact spare is for temporary emergency use only.
You can identify if your vehicle is equipped with a compact
spare by looking at the spare tire description on the Tire and
Loading Information Placard located on the driver’s side
door opening or on the sidewall of the tire. Compact spare
tire descriptions begin with the letter “T” or “S” preceding
the size designation. Example: T145/80D18 103M.
T, S = Temporary Spare Tire
Since this tire has limited tread life, the original equipment
tire should be repaired (or replaced) and reinstalled on your
vehicle at the first opportunity.
Do not install a wheel cover or attempt to mount a conven -
tional tire on the compact spare wheel, since the wheel is
designed specifically for the compact spare tire. Do not
install more than one compact spare tire and wheel on the
vehicle at any given time. Collapsible Spare Tire — If Equipped
The collapsible spare is for temporary emergency use only.
You can identify if your vehicle is equipped with a collaps -
ible spare by looking at the spare tire description on the Tire
and Loading Information Placard located on the driver’s side
door opening or on the sidewall of the tire.
Collapsible spare tire description example: 165/80-17 101P.
Since this tire has limited tread life, the original equipment
tire should be repaired (or replaced) and reinstalled on your
vehicle at the first opportunity.
Inflate collapsible tire only after the wheel is properly
installed to the vehicle. Inflate the collapsible tire using the
electric air pump before lowering the vehicle. WARNING!
Compact and collapsible spares are for temporary
emergency use only. With these spares, do not drive
more than 50 mph (80 km/h). Temporary use spares 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.

SERVICING AND MAINTENANCE 463
Do not install a wheel cover or attempt to mount a conven -
tional tire on the collapsible spare wheel, since the wheel is
designed specifically for the collapsible spare tire.
Full Size Spare — If Equipped
The full size spare is for temporary emergency use only. This
tire may look like the originally equipped tire on the front or
rear axle of your vehicle, but it is not. This spare tire may
have limited tread life. When the tread is worn to the tread
wear indicators, the temporary use full size spare tire needs
to be replaced. Since it is not the same as your original equip -
ment tire, replace (or repair) the original equipment tire and
reinstall on the vehicle at the first opportunity. Limited Use Spare — If Equipped
The limited use spare tire is for temporary emergency use
only. This tire is identified by a label located on the limited
use spare wheel. This label contains the driving limitations
for this spare. This tire may look like the 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 as your original equipment
tire, replace (or repair) the original equipment tire and rein -
stall on the vehicle at the first opportunity.WARNING!
Compact and Collapsible spares are for temporary
emergency use only. With these spares, do not drive
more than 50 mph (80 km/h). Temporary use spares 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. WARNING!
Limited use spares are for emergency use only.
Installation of this limited use spare tire affects vehicle
handling. With this tire, do not drive more than the
speed listed on the limited use spare wheel. Keep
inflated to the cold tire inflation pressures listed on your
Tire and Loading Information Placard located on the
driver’s side B-Pillar or the rear edge of the driver’s side
door. Replace (or repair) the original equipment tire at
the first opportunity and reinstall it on your vehicle.
Failure to do so could result in loss of vehicle control. 7

SERVICING AND MAINTENANCE 465
Dark Vapor Chrome, Black Satin Chrome, or Low Gloss
Clear Coat Wheels
Tire Chains (Traction Devices)
Use of traction devices require sufficient tire-to-body clear -
ance. Follow these recommendations to guard against
damage.
• Traction device must be of proper size for the tire, as
recommended by the traction device manufacturer.
Please follow the table below for proper tire size, chain type,
and axle recommendations:CAUTION!
If your vehicle is equipped with these specialty wheels,
DO NOT USE wheel cleaners, abrasives, or polishing
compounds. They will permanently damage this finish
and such damage is not covered by the New Vehicle
Limited Warranty. HAND WASH ONLY USING MILD
SOAP AND WATER WITH A SOFT CLOTH. Used on a
regular basis; this is all that is required to maintain this
finish.
Vehicle Axle Recommendations Tire Sizes Chain Class
Chassis Cab 3500 (Single Rear
Wheel) Models Rear Only LT275/70R18E U Class
Chassis Cab 3500 (Dual Rear
Wheel) 4X2 Models Rear Only LT235/80R17E U Class
Chassis Cab 3500 (Dual Rear
Wheel) 4X4 Models Front/Rear LT235/80R17E U Class
Chassis Cab 4500/5500 Models Rear Only 225/70R19.5G U Class 7