wheel size JEEP GRAND CHEROKEE 2012 WK2 / 4.G 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 passen-
ger
•Supplemental Active Head Restraints (AHR) located
on top of the front seats (integrated into the head
restraint)
•Supplemental Side Air Bag Inflatable Curtains
(SABIC) for the driver and passengers seated next to a
window
•Supplemental Seat-Mounted Side Air Bags (SAB)
•An energy-absorbing steering column and steering
wheel
•Knee bolsters 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
2
THINGS TO KNOW BEFORE STARTING YOUR VEHICLE 49

are possible, based on 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.
Supplemental Seat-Mounted Side Air Bag (SAB)
Inflator Units
The Supplemental Seat-Mounted Side Air Bags are de-
signed to activate only in certain side collisions.
The ORC determines if a side collision requires the side
air bags to inflate, based on several factors, including the
severity and type of collision.based on several factors, including the severity and type
of collision, the side air bag inflator on the crash side of
the vehicle may be triggered, releasing a quantity of
non-toxic gas. The inflating SAB exits through the seat
seam into the space between the occupant and the door.
The SAB fully inflate in about 10 milliseconds. The side
air bag moves at a very high speed and with such a high
force that it could injure you if you are not seated
properly, or if items are positioned in the area where the
side air bag inflates. This especially applies to children.
Supplemental Side Air Bag Inflatable Curtain
(SABIC) Inflator Units
During collisions where the impact is confined to a
particular area of the side of the vehicle, the ORC may
deploy the SABIC air bags, depending on the severity
and type of collision. In these events, the ORC will
deploy the SABIC only on the impact side of the vehicle.
2
THINGS TO KNOW BEFORE STARTING YOUR VEHICLE 75

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
TPMS from functioning properly. Always check theTPMS 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.4
UNDERSTANDING YOUR INSTRUMENT PANEL 289

Tires — General Information ............. 487
▫ Tire Pressure ....................... 487
▫ Tire Inflation Pressures ................ 488
▫ Tire Pressures For High Speed Operation . . . 490
▫ Radial-Ply Tires ..................... 490
▫ Spare Tire Matching Original Equipped Tire
And Wheel – If Equipped .............. 490
▫ Compact Spare Tire – If Equipped ........ 491
▫ Full Size Spare – If Equipped ............ 492
▫ Limited-Use Spare – If Equipped ......... 492
▫ Tire Spinning ....................... 493
▫ Tread Wear Indicators ................. 494
▫ Life Of Tire ........................ 494 ▫
Replacement Tires .................... 495
 Tire Chains (Traction Devices) ............. 496
 Snow Tires .......................... 498
 Tire Rotation Recommendations ........... 498
 Tire Pressure Monitor System (TPMS) ....... 499
▫ Base System ........................ 502
▫ Premium System – If Equipped .......... 504
▫ General Information .................. 508
 Fuel Requirements ..................... 509
▫ 3.6L Engine ........................ 509
▫ 5.7L Engine ........................ 509
▫ Reformulated Gasoline ................ 510
▫ Gasoline/Oxygenate Blends ............. 510
410 STARTING AND OPERATING

ABS and Traction Control, provides resistance to any
wheel that is slipping to allow additional torque transfer
to wheels with traction.
NOTE:The Quadra-Trac I system is not appropriate
for conditions where 4WD LOW range is recommended.
Refer to “Off-Road Driving Tips” in “Starting and Oper-
ating” for further information.
Quadra-Trac II Operating Instructions/
Precautions – If Equipped
The Quadra-Trac II transfer case is fully automatic in the
normal driving 4WD AUTO mode. The Quadra-Trac II 
transfer case provides three mode positions:
•4WD HI
•NEUTRAL
•4WD LOW
This transfer case is fully automatic in the 4WD HI mode. When additional traction is required, the 4WD LOW
position can be used to lock the front and rear driveshafts
together and force the front and rear wheels to rotate at
the same speed. The 4WD LOW position is intended for
loose, slippery road surfaces only. Driving in the 4WD
LOW position on dry, hard-surfaced roads may cause
increased tire wear and damage to driveline components.
When operating your vehicle in 4WD LOW, the engine
speed is approximately three times that of the 4WD HI
position 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
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 441

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
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
5
STARTING AND OPERATING 491

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 asyour 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 as
your original equipment tire, replace (or repair) the
original equipment tire and reinstall on the vehicle at the
first opportunity.
492 STARTING AND OPERATING

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 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 original wheels.
It is recommended you contact your original equipment
or an authorized tire 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.
5
STARTING AND OPERATING 495

WARNING!
•Do not use a tire, wheel size or rating other than
that specified for your vehicle. Some combinations
of unapproved tires and wheels may change sus-
pension dimensions and performance characteris-
tics, resulting in changes to steering, handling, and
braking of your vehicle. This can cause unpredict-
able handling and stress to steering and suspen-
sion components. 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.
•Never use a tire with a smaller load index or
capacity than what was originally equipped on
your vehicle. Using a tire with a smaller load index
could result in tire overloading and failure. You
could lose control and have a collision.(Continued)
WARNING! (Continued)
•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.
TIRE CHAINS (TRACTION DEVICES)
Use of traction devices require sufficient tire-to-body
clearance. Follow these recommendations to guard
against damage.
•Install on Rear Tires Only
496 STARTING AND OPERATING

Light will still be ON. In this situation, the Tire Pressure
Monitoring Telltale Light will turn OFF only after the
tires have been inflated to the vehicle’s recommended
cold tire pressure value.
CAUTION!
•The TPMS has been optimized for the original
equipment tires and wheels. TPMS pressures have
been established for the tire size equipped on your
vehicle. Undesirable system operation or sensor
damage may result when using replacement
equipment that is not of the same size, type, and/or
style. Aftermarket wheels can cause sensor dam-
age. Do not use aftermarket tire sealants or balance
beads if your vehicle is equipped with a TPMS, as
damage to the sensors may result.(Continued)
CAUTION! (Continued)
•After inspecting or adjusting the tire pressure
always reinstall the valve stem cap. This will
prevent moisture and dirt from entering the valve
stem, which could damage the Tire Pressure Moni-
toring Sensor.
NOTE:
•The TPMS is not intended to replace normal tire care
and maintenance, or to provide warning of a tire
failure or condition.
•The TPMS should not be used as a tire pressure gauge
while adjusting your tire 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.
5
STARTING AND OPERATING 501