wheel size JEEP COMMANDER 2008 1.G Owners Manual

This vehicle has airbags for both the driver and right
front passenger as a supplement to the seat belt restraint
systems. The driver's front airbag is mounted in the
steering wheel. The passenger side airbag is mounted in
the instrument panel, above the glove compartment. The
words SRS/AIRBAG are embossed on the airbag covers.
NOTE:The front airbags are certified to the Federal
regulations that allow less forceful deployment.
The front airbags have a multistage inflator design. This
may allow the airbag to have different rates of inflation
that are based on collision severity and occupant size.
This vehicle is equipped with window bags to protect the
driver, front, and rear passengers sitting next to a win-
dow. They are located above the side windows. Their
covers are also labeled SRS/AIRBAG.NOTE:Airbag covers may not be obvious in the interior
trim; but they will open to allow airbag deployment.
Window Airbag Location
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²TheDriver and Passenger Airbag/Inflator Unitsare
located in the center of the steering wheel and the right
side of the instrument panel. When the ORC detects a
collision requiring the airbags, it signals the inflator
units. A large quantity of nontoxic gas is generated to
inflate the front airbags. Different airbag inflation rates
are possible, based on collision severity and occupant
size. The steering wheel hub trim cover and the upper
right side of the instrument panel separate and fold
out of the way as the bags inflate to their full size. The
bags fully inflate in about 50±70 milliseconds. This is
about half of the time it takes to blink your eyes. The
bags then quickly deflate while helping to restrain the
driver and front passenger.
The driver front airbag gas is vented through the vent
holes in the sides of the airbag. The passenger front
airbag gas is vented through the vent holes in the sides
of the airbag. In this way, the airbags do not interfere
with your control of the vehicle.²TheSide Impact SRS Side Curtain Airbagsare de-
signed to activate only in certain side or rollover
collisions. When the Occupant Restraint Control Mod-
ule (ORC) detects a collision requiring the window
bags to inflate, it signals the inflators on the crash side
of the vehicle both sides of the vehicle if equipped
with rollover sensing. A quantity of nontoxic gas is
generated to inflate the window bag. The inflating
window bag pushes the outside edge of the headliner
out of the way and covers the window. The airbag
inflates in about 30 milliseconds (about one-quarter of
the time it takes to blink your eyes) with enough force
to injure you if you are not belted and seated properly,
or if items are positioned in the area where the
window bag inflates. This especially applies to chil-
dren. The window bag is only about 3 inches (8 cm)
thick when it is inflated.
54 THINGS TO KNOW BEFORE STARTING YOUR VEHICLE

of reasons, including the installation of replacement or
alternate tires or wheels on the vehicle that prevent the
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 replace-
ment 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. After-market wheels can cause
sensor damage. Do not use aftermarket tire sealants
or balance beads if your vehicle is equipped with a
TPMS, as damage to the sensors may result.
13. Temperature Gauge
The temperature gauge shows engine coolant tempera-
ture. Any reading within the normal range indicates that
the engine cooling system is operating satisfactorily.
UNDERSTANDING YOUR INSTRUMENT PANEL 191
4

Quadra-Trac IITOperating
Instructions/Precautions Ð If Equipped
The Quadra-Trac IIttransfer case is fully automatic in the
normal driving 4 HI mode. The Quadra-Trac IIttransfer
case provides three mode positions Ð four wheel drive
high range, neutral, and four wheel drive low range.
This transfer case is fully automatic in the 4 HI mode.
This transfer case divides engine torque almost evenly
with 48 percent of engine torque to the front axle and 52
percent of engine torque to the rear axle. When speed
differences are increased between the front and rear drive
shafts, the transfer case can transmit up to 100 percent of
available engine torque to the front or rear drive shafts.
When additional traction is required, the 4 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 4 LOW position is intended for loose, slipperyroad surfaces only. Driving in the 4 LOW position on dry
hard surfaced roads may cause increased tire wear and
damage to driveline components.
When operating your vehicle in 4 LOW, the engine speed
is approximately three times that of the 4 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.
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When parking on a hill, turn the front wheels toward the
curb on a downhill grade and away from the curb on an
uphill grade.
The parking brake should always be applied whenever
the driver is not in the vehicle.
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 you have your foot
lightly on the brake while this test is occurring, you may
feel slight pedal movement. The movement can be more
apparent on ice and snow. This is normal.
The Anti-Lock Brake System pump motor runs during
the self-test at 12 mph (20 km/h) and during an ABS stop.
The pump motor makes a low humming noise during
operation, which is normal.
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CAUTION!
Prolonged operation of the steering system at the end
of the steering wheel travel will increase the steering
fluid temperature and it should be avoided when
possible. Damage to the power steering pump may
occur.
MULTI DISPLACEMENT SYSTEM (MDS) Ð 5.7L
Engine Only
This feature offers improved fuel economy by shutting
off four of the engine's eight cylinders during light load
and cruise conditions. The system is automatic with no
driver inputs or additional driving skills required.
NOTE:The MDS system may take some time to return
to full functionality after a battery disconnect.
TIRE SAFETY INFORMATION
Tire Markings
NOTE:
²P (Passenger)-Metric tire sizing is based on U.S. design
standards. P-Metric tires have the letter ªPº molded
into the sidewall preceding the size designation. Ex-
ample: P215/65R15 95H.
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WARNING!
²Do not use a tire, wheel size or rating other than
that specified for your vehicle. Some combina-
tions of unapproved tires and wheels may change
suspension dimensions and performance charac-
teristics, resulting in changes to steering, han-
dling, and braking of your vehicle. This can cause
unpredictable handling and stress to steering and
suspension components. You could lose control
and have an accident resulting in serious injury
or death. Use only the tire and wheel sizes with
load ratings approved for your vehicle.
²Never use a tire with a smaller load index or
capacity, other 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 an accident.
²Failure 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
readings.
Alignment and Balance
Poor suspension alignment may result in:
²Fast tire wear.
²Uneven tire wear, such as feathering and one-sided
wear.
²Vehicle pull to right or left.
Tires may also cause the vehicle to pull left or right.
Alignment will not correct this problem. See your autho-
rized dealer for proper diagnosis.
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Improper alignment will not cause vehicle vibration.
Vibration may be a result of tire and wheel out-of-
balance. Proper balancing will reduce vibration and
avoid tire cupping and spotty wear.
TIRE CHAINS
Only models fitted with 235/65R17XL (extra load) tires
have sufficient tire-to-body clearance to allow use of tire
chains.Install chains on rear tires only.Follow these
recommendations to guard against damage and exces-
sive tire and chain wear:
²Do not install tire chains or traction devices on ve-
hicles with larger than 235/65R17XL size tires. Tires
larger than this may not provide sufficient body
clearance with chains or other traction devices.
²Manufacturer recommends a cold inflation pressure of
38 psi (262 kPa) when using 235/65R17XL size tires for
this vehicle.
²Use SAE class ªSº tire chains or traction devices only.
²Follow tire chain manufacturer's instructions for
mounting chains.
²Install chains snugly and tighten after 1/2 mile (1 km)
of driving.
²Do notexceed 30 mph (48 km/h), unless otherwise
specified by the chain manufacturer.
²Drive cautiously, avoiding large bumps, potholes and
extreme driving maneuvers.
TIRE ROTATION RECOMMENDATIONS
Tires on the front and rear axles of vehicles operate at
different loads and perform different steering, handling,
and braking functions. For these reasons, they wear at
unequal rates, and develop irregular wear patterns.
These effects can be reduced by timely rotation of tires.
The benefits of rotation are especially worthwhile with
322 STARTING AND OPERATING

Telltale Lightº 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 equip-
ment that is not of the same size, type, and/or style.
Aftermarket wheels can cause sensor damage. Do not
use aftermarket tire sealants or balance beads if your
vehicle is equipped with a TPMS, as damage to the
sensors may result.
CAUTION!
After inspecting or adjusting the tire pressure always
reinstall the valve stem cap. This will prevent mois-
ture and dirt from entering the valve stem, which
could damage the Tire Pressure Monitoring Sensor.
NOTE:
²The TPMS is not intended to replace normal tire care
and maintenance, or to provide warning of a tire
failure or condition.
²The TPMS should not be used as a tire pressure gauge
while adjusting your tire pressure.
²Driving 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.
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5

²The TPMS is not a substitute for proper tire mainte-
nance, and it is the driver 's responsibility to maintain
correct tire pressure using an accurate tire gauge, even
if under-inflation has not reached the level to trigger
illumination of the ªTire Pressure Monitoring Telltale
Light.º
²Seasonal temperature changes will affect tire pressure,
and the TPM system will monitor the actual tire
pressure in the tire.
Base System Ð If Equipped
The Tire Pressure Monitor System (TPMS) uses wireless
technology with wheel rim mounted electronic sensors to
monitor tire pressure levels. Sensors, mounted to each
wheel as part of the valve stem, transmit tire pressure
readings to the Receiver Module.
NOTE:It is particularly important, for you to check the
tire pressure in all of your tires regularly and to maintain
the proper pressure.The Tire Pressure Monitor System (TPMS) consists of the
following components:
²Receiver Module
²4 Tire Pressure Monitoring Sensors
²Tire Pressure Monitoring Telltale Light
A tire pressure monitoring sensor is located in the spare
wheel if the vehicle is equipped with a matching full size
spare wheel and tire assembly. The matching full size
spare tire can be used in place of any of the four road
tires. A low spare tire will not cause the ªTire Pressure
Monitoring Telltale Lightº to illuminate or the chime to
sound.
The ªTire Pressure Monitoring Telltale Lightº will
illuminate in the instrument cluster, and an au-
dible chime will be activated when one or more of
the four active road tire pressures are low. Should this
occur, you should stop as soon as possible, check the
326 STARTING AND OPERATING