JEEP WRANGLER 2008 JK / 3.G Owners Manual

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WARNING!
Overloading of your tires is dangerous. Overloading
can cause tire failure, affect vehicle handling, and
increase your stopping distance. Use tires of the
recommended load capacity for your vehicle. Never
overload them.
TIRES — GENERAL INFORMATION
Tire Pressure
Proper tire inflation pressure is essential to the safe and
satisfactory operation of your vehicle. Three primary
areas are affected by improper tire pressure:
Safety
WARNING!
Improperly inflated tires are dangerous and can cause
accidents.
•Under-inflation increases tire flexing and can result in
tire failure.
• Over-inflation reduces a tire’s ability to cushion
shock. Objects on the road and chuck holes can cause
damage that results in tire failure.
• Unequal tire pressures can cause steering problems.
You could lose control of your vehicle.
• Over-inflated or under-inflated tires can affect vehicle
handling and can fail suddenly, resulting in loss of
vehicle control.
• Unequal tire pressures from one side of the vehicle to
the other can cause the vehicle to drift to the right or left.
Always drive with each tire properly inflated.
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Economy
Improper inflation pressures can cause uneven wear
patterns to develop across the tire tread. These abnormal
wear patterns will reduce tread life resulting in a need for
earlier tire replacement. Under-inflation also increases
tire rolling resistance and results in higher fuel consump-
tion.
Ride Comfort and Vehicle Stability
Proper tire inflation contributes to a comfortable ride.
Over-inflation produces a jarring and uncomfortable
ride.
Tire Inflation Pressures
Tire Placard Location (Two-Door Models)
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Tire pressure should be checked and adjusted as well as
inspecting for signs of tire wear or visible damage, at
least once a month. Use a good quality pocket-type gauge
to check tire pressure. Do not make a visual judgement
when determining proper inflation. Radial tires may look
properly inflated even when they are under inflated.
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.
Inflation pressures specified on the placard are always
“cold tire inflation pressure.” Cold tire inflation pressure
is defined as the tire pressure after the vehicle has not
been driven for at least three hours, or driven less than 1
mi (1 km) after a three hour period. The cold tire inflation
pressure must not exceed the maximum inflation pres-
sure molded into the tire side wall.
Check tire pressures more often if subject to a wide range
of outdoor temperatures, as tire pressures vary with
temperature changes.
Tire Placard Location (Four-Door Models)
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Tire pressures change by approximately 1 psi (7 kPa) per
12° F (7° C) of air temperature change. Keep this in mind
when checking tire pressure inside a garage especially in
the winter.
Example: If garage temperature = 68° F (20° C) and the
outside temperature = 32° F (0° C) then the cold tire
inflation pressure should be increased by 3 psi (21 kPa),
which equals 1 psi (7 kPa) for every 12° F (7° C) for this
outside temperature condition.
Tire pressure may increase from 2 to 6 psi (13 to 40 kPa)
during operation. DO NOT reduce this normal pressure
buildup or your tire pressure will be too low.
Tire Pressures for High-Speed Operation
The manufacturer advocates driving at safe speeds
within posted speed limits. Where speed limits or condi-
tions are such that the vehicle can be driven at high
speeds, maintaining correct tire inflation pressure is very
important. Increased tire pressure and reduced vehicleloading may be required for high-speed vehicle opera-
tion. Refer to original equipment or an authorized tire
dealer for recommended safe operating speeds, loading
and cold tire inflation pressures.
WARNING!
High speed driving with your vehicle under load is
dangerous. The added strain on your tires could
cause them to fail. You could have a serious accident.
Do not drive a vehicle loaded to maximum capacity at
continuous speeds above 75 mph (120 km/h).
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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 an accident. Al-
ways use radial tires in sets of four. Never combine
them with other types of tires.
Cuts and punctures in radial tires are repairable only in
the tread area because of sidewall flexing. Consult your
authorized dealer for radial tire repairs.
Tire Spinning
When stuck in mud, sand, snow, or ice conditions, do not
spin your vehicle’s wheels above 35 mph (55 km/h).
WARNING!
Fast spinning tires can be dangerous. Forces gener-
ated by excessive wheel speeds may cause tire dam-
age or failure. A tire could explode and injure some-
one. Do not spin your vehicle’s wheels faster than 35
mph (55 km/h) when you are stuck, and do not let
anyone near a spinning wheel no matter what the
speed.
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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 and will appear as bands when the tread depth
becomes 1/16 inch (2 mm). When the indicators appear
in two or more adjacent grooves, the tire should be
replaced.
Many states have laws requiring tire replacement at this
point.
Life of Tire
The service life of a tire is dependent upon varying
factors including but not limited to:
•Driving style
•Tire pressure
•Distance driven
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WARNING!
Tires and 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 an accident resulting in
serious injury or death.
Keep unmounted 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 (see the paragraph on tread
wear indicators). Refer to the Tire and Loading Informa-
tion placard for the size designation of your tire. The
service description and load identification will be found
on the original equipment tire. Failure to use equivalent
replacement tires may adversely affect the safety, han-
dling, and ride of your vehicle. We recommend that you
contact your original equipment or an authorized tire
dealer with any questions you may have on tire specifi-
cations or capability.
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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 suspension
dimensions and performance characteristics, result-
ing in changes to steering, handling, 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.
• Never 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.
• Failure to equip your vehicle with tires having ad-
equate 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:
•Fast tire wear.
•Uneven tire wear, such as feathering and one-sided
wear.
•Vehicle 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
Install chains on rear tires only. Tire chains may be
installed on all models except the Sahara and Rubicon.
Follow these recommendations to guard against damage
and excessive tire and chain wear:
•Use chains on P225/75R16 tires only. P245/75R16,
P255/75R17, P255/70R18, and LT255/75R17 tires do
not provide adequate clearance.
•Use SAE class “S” tire chains or traction devices only.
•Chains must be the proper size for the vehicle, as
recommended by the chain manufacturer.
•Follow tire chain manufacturer’s instructions for
mounting chains.
•Install chains snugly and tighten after 0.6 mi (1 km) of
driving.
•Do notexceed 30 mph (48 km/h).
•Drive 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
aggressive tread designs such as those on On/Off Road
type tires. Rotation will increase tread life, help to main-
tain mud, snow, and wet traction levels, and contribute to
a smooth, quiet ride.
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