tire size Ram 2500 2018 Owner's Manual

To determine the maximum loading condi-
tions 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 appli-
cable) should never exceed the weight refer-
enced here.
Steps For Determining Correct Load
Limit—
(1) Locate the statement “The com-
bined weight of occupants and cargo
should never exceed XXX kg or
XXX lbs.” 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 passengers from XXX kg
or XXX lbs.(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.
(1400-750 (5x150) = 650 lbs.)
(5)Determine the combined weight of
luggage and cargo being loaded on the
vehicle. That weight may not safely ex-
ceed 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 lug-
gage load capacity of your vehicle.
Metric Example For Load Limit
For example, if “XXX” amount equals 635 kg
and there will be five 68 kg passengers in
your vehicle, the amount of available cargo
and luggage load capacity is 295 kg (635-
340 (5x68) = 295 kg) as shown in step 4.
NOTE:
• If your vehicle will be towing a trailer, load from your trailer will be transferred to your
vehicle. The following table shows ex-
amples on how to calculate total load,
cargo/luggage, and towing capacities of
your vehicle with varying seating configura-
tions 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.
SERVICING AND MAINTENANCE
262

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 a collision. Always use radial
ply tires in sets of four. Never combine
them with other types of tires.
Tire Repair
If your tire becomes damaged, it may be
repaired if it meets the following criteria:
• The tire has not been driven on when flat.
• The damage is only on the tread section of your tire (sidewall damage is not repair-
able).
• The puncture is no greater thana¼ofan inch (6 mm).
Consult an authorized tire dealer for tire re-
pairs and additional information. Damaged Run Flat tires, or Run Flat tires that
have experienced a loss of pressure should be
replaced immediately with another Run Flat
tire of identical size and service description
(Load Index and Speed Symbol).
Run Flat Tires — If Equipped
Run Flat tires allow you the capability to drive
50 miles (80 km) at 50 mph (80 km/h) after
a rapid loss of inflation pressure. This rapid
loss of inflation is referred to as the Run Flat
mode. A Run Flat mode occurs when the tire
inflation pressure is of/or below 14 psi
(96 kPa). Once a Run Flat tire reaches the
run flat mode it has limited driving capabili-
ties and needs to be replaced immediately. A
Run Flat tire is not repairable.
It is not recommended driving a vehicle
loaded at full capacity or to tow a trailer while
a tire is in the run flat mode.
See the tire pressure monitoring section for
more information.
Tire Spinning
When stuck in mud, sand, snow, or ice con-
ditions, do not spin your vehicle's wheels
above 30 mph (48 km/h) or for longer than
30 seconds continuously without stopping.
Refer to “Freeing A Stuck Vehicle” in “In
Case Of Emergency” for further information.
WARNING!
Fast spinning tires can be dangerous.
Forces generated by excessive wheel
speeds may cause tire damage or failure. A
tire could explode and injure someone. Do
not spin your vehicle's wheels faster than
30 mph (48 km/h) for more than 30 sec-
onds continuously when you are stuck,
and do not let anyone near a spinning
wheel, no matter what the speed.
SERVICING AND MAINTENANCE
266

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 a
1/16 of an inch (1.6 mm). When the tread is
worn to the tread wear indicators, the tire
should be replaced. Refer to “Replacement
Tires” in this section for further information.
Life Of Tire
The service life of a tire is dependent upon
varying factors including, but not limited to:
• Driving style.
• Tire pressure - Improper cold tire inflationpressures can cause uneven wear patterns
to develop across the tire tread. These ab-
normal wear patterns will reduce tread life,
resulting in the need for earlier tire replace-
ment.
• Distance driven.
• Performance tires, tires with a speed rating of V or higher, and Summer tires typically
have a reduced tread life. Rotation of these
tires per the vehicle scheduled mainte-
nance is highly recommended.
WARNING!
Tires and the 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 a collision resulting 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 bal-
ance 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 Indi-
cators” in this section. Refer to the Tire and
Loading Information 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.
Tire Tread
1 — Worn Tire
2 — New Tire
267

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 original wheels.
It is recommended you contact your autho-
rized 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 combinations of
unapproved tires and wheels may
change suspension dimensions and per-
formance characteristics, resulting in
changes to steering, handling, and brak-
ing of your vehicle. This can cause un-
predictable handling and stress to steer-
ing and suspension components. You
WARNING!
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.
• Never use a tire with a smaller load index
or capacity, other than what was origi-
nally equipped on your vehicle. Using a
tire with a smaller load index could re-
sult in tire overloading and failure. You
could lose control and have a collision.
• 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 speedom-
eter and odometer readings.
Tire Types
All Season Tires — If Equipped
All Season tires provide traction for all sea-
sons (Spring, Summer, Fall, and Winter).
Traction levels may vary between different all
season tires. All season tires can be identi-
fied by the M+S, M&S, M/S or MS designa-
tion on the tire sidewall. Use all season tires
only in sets of four; failure to do so may
adversely affect the safety and handling of
your vehicle.
Summer Or Three Season Tires — If
Equipped
Summer tires provide traction in both wet
and dry conditions, and are not intended to
be driven in snow or on ice. If your vehicle is
equipped with Summer tires, be aware these
tires are not designed for Winter or cold
driving conditions. Install Winter tires on your
vehicle when ambient temperatures are less
than 40°F (5°C) or if roads are covered with
ice or snow. For more information, contact an
authorized dealer.SERVICING AND MAINTENANCE
268

Summer tires do not contain the all season
designation or mountain/snowflake symbol
on the tire sidewall. Use Summer tires only in
sets of four; failure to do so may adversely
affect the safety and handling of your vehicle.
WARNING!
Do not use Summer tires in snow/ice con-
ditions. You could lose vehicle control,
resulting in severe injury or death. Driving
too fast for conditions also creates the
possibility of loss of vehicle control.
Snow Tires
Some areas of the country require the use of
snow tires during the Winter. Snow tires can
be identified by a “mountain/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; fail-ure 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 sus-
tained 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 pres-
sures.
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
For vehicles equipped with Tire Service Kit
instead of a spare tire, please refer to “Tire
Service Kit” in “In Case Of Emergency” in the
Owner’s Manual for further information.
CAUTION!
Because of the reduced ground clearance,
do not take your vehicle through an auto-
matic car wash with a compact or limited
use temporary spare installed. Damage to
the vehicle may result.
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 op-
tion, refer to an authorized tire dealer for the
recommended tire rotation pattern.
Compact Spare Tire — If Equipped
The compact spare is for temporary emer-
gency use only. You can identify if your ve-
hicle 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
269

sidewall of the tire. Compact spare tire de-
scriptions 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 conventional 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.
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
WARNING!
your spare. Failure to do so could result in
spare tire failure and loss of vehicle con-
trol.
Collapsible Spare Tire — If Equipped
The collapsible spare is for temporary emer-
gency use only. You can identify if your ve-
hicle is equipped with a collapsible 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. Do not install a wheel cover or attempt to
mount a conventional tire on the collapsible
spare wheel, since the wheel is designed
specifically for the collapsible spare tire.
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 con-
trol.
Full Size Spare — If Equipped
The full size spare is for temporary emer-
gency 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
SERVICING AND MAINTENANCE
270

WHEEL AND TIRE TORQUE
SPECIFICATIONS
Proper lug nut/bolt torque is very important to
ensure that the wheel is properly mounted to
the vehicle. Any time a wheel has been re-
moved and reinstalled on the vehicle, the lug
nuts/bolts should be torqued using a properly
calibrated torque wrench using a high quality
six sided (hex) deep wall socket.
Torque Specifications
All wheel nuts should be tightened occasion-
ally to eliminate the possibility of wheel studs
being sheared or the bolt holes in the wheels
becoming elongated. This is especially im-
portant during the first few hundred miles/
kilometers of operation to allow the wheel
nuts to become properly set. All wheel nuts
should first be firmly seated against the
wheel. The wheel nuts should then be tight-
ened to recommended torque. Tighten the
wheel nuts to final torque in increments.
Progress around the bolt circle, tightening
the wheel nut opposite to the wheel nut justpreviously tightened until final torque is
achieved. Ensure that the socket is fully en-
gaged on the lug nut/bolt (do not insert it
halfway).
Recommended torques are shown in the fol-
lowing chart:
Disc Wheels
Nut
Ty p e
Stud
Size Hex
SizeTorque
Ft LbsTorque
Newton
Meters
Cone M14 x
1.5 22 mm 130 176
Flanged M14 x
1.5 22 mm 140 190
8-Stud — Dual Rear Wheels
• Dual wheels are flat-mounted and center-
piloted. The lug nuts are a two-piece as-
sembly. When the tires are being rotated or
replaced, clean these lug nuts and add two
drops of oil at the interface between the hex
and the washer. • Slots in the wheels will assist in properly
orienting the inner and outer wheels. Align
these slots when assembling the wheels for
best access to the tire valve on the inner
wheel. The tires of both dual wheels must
be completely off the ground when tighten-
ing, to ensure wheel centering and maxi-
mum wheel clamping.
Oil Interface LocationTECHNICAL SPECIFICATIONS
276

Jacking..................211
Life Of Tires ...............267
Load Capacity ..............261
Pressure Monitor System (TPMS) . . .88
Pressure Warning Light .........79
Quality Grading .............272
Radial ..................266
Replacement ..............267
Safety ...............257, 264
Sizes ...................258
Snow Tires ................269
Spare Tire .........269, 270, 271
Spinning .................266
Tread Wear Indicators .........267
Wheel Nut Torque ...........276
Tire Safety Information ...........257
To Open Hood .................50
Towing .....................191
Disabled Vehicle ............225
Guide ...................191
Recreational ...............196
Weight ..................191
Towing Vehicle Behind A Motorhome . .196
Trailer Towing ................191
Minimum Requirements .......191
Trailer Towing Guide ............191
Trailer Weight ................191 Transfer Case
Electronically Shifted . .162, 164, 166,
168 Fluid ............282, 284, 286
Transmission .................156
Automatic .........156, 158, 160
Fluid ............282, 284, 286
Shifting .................155
Transporting Pets ..............133
Tread Wear Indicators ............267
Turn Signals .............32, 33, 83
Uconnect 3.0 ................295
Uconnect

(Hands-Free Phone)
Making A Phone Call ......332, 338
Receiving A Call ............332
Uconnect Phone ........332, 337, 338
Uconnect Settings Customer Programmable Features . . .19
Passive Entry Programming .......19
Uconnect Voice Command .....337, 340
Uniform Tire Quality Grades ........272
Untwisting Procedure, Seat Belt ......98
USB Port ...................325
Utility Rails, Rear Cargo Area ........62Vehicle Loading
...............261
Vehicle Storage ................48
Vehicle User Guide ICON Symbol Glossary ..........11
In Vehicle Help ..............11
IVH .....................11
Navigation .................11
Operating Instructions ..........11
Searching User Guide ..........11
Voice Command ...............337
Voice Recognition System (VR) ..............337, 338, 340
Voltmeter ................149, 151
Warning Lights (Instrument Cluster Description) .................79
Washers, Windshield .............35
Water Separator, Diesel Fuel . . . .249, 253
Wheel And Wheel Trim ...........271
Wheel And Wheel Trim Care ........271
Wheel Cover .................217
Wheel Nut Torque ..............276
Wind Buffeting ................50
Window Fogging ................48
363