wheel size JEEP WRANGLER UNLIMITED 2013 Owners Manual

OCCUPANT RESTRAINTS
Some of the most important safety features in your
vehicle are the restraint systems:
• Three-point lap and shoulder belts for the driver and
all passengers
• Advanced Front Air Bags for driver and front
passenger
• Supplemental Seat-Mounted Side Air Bags (SAB) — if
equipped
• An energy-absorbing steering column and steering
wheel
• Knee bolsters/blockers for front seat occupants
• Front seat belts incorporate pretensioners that may
enhance occupant protection by managing occupant
energy during an impact event • All seat belt systems (except the driver’s) include
Automatic Locking Retractors (ALRs), which lock the
seat belt webbing into position by extending the belt
all the way out and then adjusting the belt to the
desired length to restrain a child seat or secure a large
item in a seat — if equipped
Please pay close attention to the information in this
section. It tells you how to use your restraint system
properly, to keep you and your passengers as safe as
possible.
If you will be carrying children too small for adult-sized
seat belts, the seat belts or the Lower Anchors and Tether
for CHildren (LATCH) feature also can be used to hold
infant and child restraint systems. For more information
on LATCH, refer to Lower Anchors and Tether for
CHildren (LATCH). 2 THINGS TO KNOW BEFORE STARTING YOUR VEHICLE 45

WARNING!Ignoring the Air Bag Warning Light in your instru-
ment panel could mean you won’t have the air bags
to protect you in a collision. If the light does not come
on as a bulb check when the ignition is first turned
on, stays on after you start the vehicle, or if it comes
on as you drive, have an authorized dealer service the
air bag system immediately.
Driver And Passenger Advanced Front Air Bag
Inflator Units
The Driver and Passenger Advanced Front Air Bag
Inflator Units are located in the center of the steering
wheel and on the right side of the instrument panel. When the ORC detects a collision requiring the Ad-
vanced Front Air Bags, it signals the inflator units. A large
quantity of non-toxic gas is generated to inflate the
Advanced Front Air Bags. Different air bag inflation rates
are possible, based on several factors, including the
collision type and severity. The steering wheel hub trim
cover and the upper right side of the instrument panel
separate and fold out of the way as the air bags inflate to
their full size. The air bags fully inflate in about 50 to
70 milliseconds. This is about half of the time it takes to
blink your eyes. The air bags then quickly deflate while
helping to restrain the driver and front passenger.
The Advanced Front Air Bag gas is vented through the
vent holes in the sides of the air bag. In this way, the air
bags do not interfere with your control of the vehicle. 2 THINGS TO KNOW BEFORE STARTING YOUR VEHICLE 69

the vehicle manufacturer on the vehicle placard or tire
inflation pressure label. (If your vehicle has tires of a
different size than the size indicated on the vehicle placard
or tire inflation pressure label, you should determine the
proper tire inflation pressure for those tires.)
As an added safety feature, your vehicle has been
equipped with a Tire Pressure Monitoring System
(TPMS) that illuminates a low tire pressure telltale when
one or more of your tires is significantly under-inflated.
Accordingly, when the low tire pressure telltale illumi-
nates, you should stop and check your tires as soon as
possible, and inflate them to the proper pressure. Driving
on a significantly under-inflated tire causes the tire to
overheat and can lead to tire failure. Under-inflation also
reduces fuel efficiency and tire tread life, and may affect
the vehicle’s handling and stopping ability. Please note that the TPMS is not a substitute for proper
tire maintenance, and it is the driver ’s responsibility to
maintain correct tire pressure, even if under-inflation has
not reached the level to trigger illumination of the TPMS
low tire pressure telltale.
Your vehicle has also been equipped with a TPMS
malfunction indicator to indicate when the system is not
operating properly. The TPMS malfunction indicator is
combined with the low tire pressure telltale. When the
system detects a malfunction, the telltale will flash for
approximately one minute and then remain continuously
illuminated. This sequence will continue upon subse-
quent vehicle start-ups as long as the malfunction exists.
When the malfunction indicator is illuminated, the sys-
tem may not be able to detect or signal low tire pressure
as intended. TPMS malfunctions may occur for a variety
of reasons, including the installation of replacement or
alternate tires or wheels on the vehicle that prevent the 4 UNDERSTANDING YOUR INSTRUMENT PANEL 307

TPMS from functioning properly. Always check the
TPMS malfunction telltale after replacing one or more
tires or wheels on your vehicle, to ensure that the
replacement or alternate tires and wheels allow the TPMS
to continue to function properly.
CAUTION!The TPMS has been optimized for the original
equipment tires and wheels. TPMS pressures and
warning have been established for the tire size
equipped on your vehicle. Undesirable system opera-
tion or sensor damage may result when using re-
placement equipment that is not of the same size,
type, and/or style. Aftermarket wheels can cause
sensor damage. Do not use tire sealant from a can or
balance beads if your vehicle is equipped with a
TPMS, as damage to the sensors may result. 24. Odometer / Trip Odometer Display Area
The odometer display shows the total distance the vehicle
has been driven. The trip odometer shows individual trip
mileage. Refer to “Odometer/Trip Odometer/ECO (Fuel
Saver Indicator) Button” for additional information.
U.S. Federal regulations require that upon transfer of
vehicle ownership, the seller certify to the purchaser the
correct mileage that the vehicle has been driven. If your
odometer needs to be repaired or serviced, the repair
technician should leave the odometer reading the same
as it was before the repair or service. If s/he cannot do so,
then the odometer must be set at zero, and a sticker must
be placed in the door jamb stating what the mileage was
before the repair or service. It is a good idea for you to
make a record of the odometer reading before the repair/
service, so that you can be sure that it is properly reset, or
that the door jamb sticker is accurate if the odometer
must be reset at zero.308 UNDERSTANDING YOUR INSTRUMENT PANEL

▫ Traction Control System (TCS) ........... .457
▫ Brake Assist System (BAS) .............. .457
▫ Hill Start Assist (HSA) ................ .458
▫ Electronic Roll Mitigation (ERM) ......... .462
▫ Electronic Stability Control (ESC) ......... .463
▫ ESC Activation/Malfunction Indicator Light
And ESC OFF Indicator Light ........... .468
▫ Trailer Sway Control (TSC) ............. .469
▫ Hill Descent Control (HDC) – If Equipped . . .470
 TIRE SAFETY INFORMATION ............ .471
▫ Tire Markings ....................... .471
▫ Tire Identification Number (TIN) .......... .475
▫ Tire Terminology And Definitions ......... .476 ▫ Tire Loading And Tire Pressure .......... .477
 TIRES — GENERAL INFORMATION ........ .482
▫ Tire Pressure ....................... .482
▫ Tire Inflation Pressures ................ .483
▫ Tire Pressures For High Speed Operation . . . .485
▫ Radial Ply Tires ..................... .485
▫ All Season Tires – If Equipped ........... .485
▫ Summer Or Three Season Tires – If Equipped. .486
▫ Snow Tires ......................... .486
▫ Spare Tire Matching Original Equipped Tire
And Wheel – If Equipped ............... .487
▫ Compact Spare Tire – If Equipped ........ .487
▫ Full Size Spare – If Equipped ............ .488
5 STARTING AND OPERATING 407

In the event that additional traction is required, the
transfer case 4H and 4L positions can be used to lock the
front and rear driveshafts together, forcing the front and
rear wheels to rotate at the same speed. This is accom-
plished by simply moving the shift lever to one of these
positions. The 4H and 4L positions are intended for loose,
slippery road surfaces only and not intended for normal
driving. Driving in the 4H and 4L positions on hard-
surfaced roads will cause increased tire wear and damage
to the driveline components.
The “4WD Indicator Light” (located in the instrument
cluster) alerts the driver that the vehicle is in four-wheel
drive, and the front and rear driveshafts are locked
together. The light will illuminate when the transfer case
is shifted into the 4H position.
NOTE: Do not attempt to shift when only the front or
rear wheels are spinning. The transfer case is not
equipped with a synchronizer, and the front and rear driveshaft speeds must be equal for a shift to take place.
Shifting while only the front or rear wheels are spinning
can cause damage to the transfer case.
When operating your vehicle in 4L, the engine speed will
be approximately three times (four times for Rubicon
models) that of the 2H or 4H positions at a given road
speed. Take care not to overspeed the engine.
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
cause damage to the transfer case.
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.
5 STARTING AND OPERATING 429

ANTI-LOCK BRAKE SYSTEM
The Anti-Lock Brake System (ABS) is designed to aid the
driver in maintaining vehicle control under adverse
braking conditions. The system operates with a separate
computer to modulate hydraulic pressure to prevent
wheel lock-up and help avoid skidding on slippery
surfaces.
All vehicle wheels and tires must be the same size and
type, and tires must be properly inflated to produce
accurate signals for the computer.
WARNING!Significant over or under-inflation of tires, or mixing
sizes of tires or wheels on the vehicle can lead to loss
of braking effectiveness. The Anti-Lock Brake System conducts a low speed self-
test at about 12 mph (20 km/h). If for any reason your
foot is on the brake when the vehicle reaches 12 mph
(20 km/h), this check will be delayed until 25 mph
(40 km/h).
The Anti-Lock Brake System pump motor runs during
the self-test, and during an ABS stop, to provide the
regulated hydraulic pressure. The motor pump makes a
low humming noise during operation; this is normal.
WARNING!• Pumping of the Anti-Lock Brakes will diminish
their effectiveness and may lead to a collision.
Pumping makes the stopping distance longer. Just
press firmly on your brake pedal when you need to
slow down or stop. (Continued)
5 STARTING AND OPERATING 455

Enabling HDC
1. Shift the transfer case into 4WD LOW range. Refer to
“Four-Wheel Drive Operation” in “Starting and Oper-
ating” for further information.
2. Press the “Hill Descent” button. The “Hill Descent
Control Indicator Light” in the instrument cluster will
turn on solid.
NOTE: If the transfer case is not in 4WD LOW range, the
“Hill Descent Control Indicator Light” will flash for five
seconds and HDC will not be enabled.
Disabling HDC
Press the “Hill Descent” button or shift the transfer case
out of 4WD LOW range. The “Hill Descent Control
Indicator” light in the instrument cluster will turn off. TIRE SAFETY INFORMATION
Tire Markings
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 Grades
5 STARTING AND OPERATING 471

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.
If your vehicle is not equipped with an original equip-
ment tire and wheel as a spare, a non-matching tempo-
rary emergency use spare may be equipped with your
vehicle. Temporary use spares are engineered to be used
only with your vehicle. Your vehicle may be equipped
with one of the following types of non-matching tempo-
rary use spares; compact, full size, or limited-use. Do not
install more than one non-matching temporary use 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 a
compact, full size or limited-use temporary spare
installed. Damage to the vehicle may result.
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
5 STARTING AND OPERATING 487

Since this tire has limited tread life the original equip-
ment 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 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. Full Size Spare – If Equipped
The full size spare is for temporary emergency use only.
This tire may look like the original 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 equipment 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 as488 STARTING AND OPERATING