2004 JEEP WRANGLER Owners Manual

High Speed Operation
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.
Don't drive a vehicle loaded to maximum capacity at
continuous speeds above 75 mph (120 km/h).
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, correct tire inflation pressure is very important.
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
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).
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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
someone. Do not spin your vehicle's wheels faster
than 35 mph (55km/h) when you are stuck. And don't
let anyone near a spinning wheel, no matter what the
speed.
Tread Wear Indicators
These indicators are narrow strips 1/16 inch (1.6 mm)
thick and are found in the tread pattern grooves.
When the tread pattern is worn down to these treadwear
indicators, the tires should be replaced.
Overloading your vehicle, long trips in very hot weather,
and driving on bad roads may result in greater wear.
Replacement Tires
The tires on your new vehicle provide a balance of many
characteristics. They should be inspected regularly for
wear and correct inflation pressure. The manufacturer
strongly recommends that you use tires equivalent to the
originals in quality and performance when replacement
is needed (see section on tread wear indicators). Failure
to use equivalent replacement tires may adversely affect
the safety, handling and ride of your vehicle. We recom-
mend that you contact your original equipment tire
dealer on any questions you may have on tire specifica-
tions or capability.
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WARNING!
²Do not use a tire, wheel size or rating other than that
specified for your vehicle. Some combinations of
unapproved tires and wheels may change suspen-
sion dimensions and performance characteristics,
resulting in changes to steering, handling, and brak-
ing of your vehicle. This can cause unpredictable
handling and stress to steering and suspension com-
ponents. 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 smaller than the minimum tire size
listed on your vehicle's tire label. Using a smaller tire
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.
²Overloading your tires is dangerous. Overloading
can cause tire failure. Use tires of the recommended
load capacity for your vehicle - never overload them.
CAUTION!
Replacing original tires with tires of a different size
may result in false speedometer and odometer read-
ings. Check with your dealer before replacing tires
with a different size.
Alignment And Balance
Tire suspension components of your vehicle should be
inspected and aligned when needed, to obtain maximum
tire tread life.
Poor suspension alignment may result in:
²reduced tread life;
²uneven tire wear, such as feathering and one-sided
wear,
²vehicle pull to the right or to the left.
Tires may also cause your vehicle to pull to the left or
right. Alignment won't correct this condition. See your
dealer for proper diagnosis.
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Improper alignment will not cause vehicle vibration,
which 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 Sahara. Follow these
recommendations to guard against damage and exces-
sive tire and chain wear:
²Use chains on P205/75R15 or P215/75R15 tires only.
P225/75R15, LT30 x 9.50R15, and LT245/75R16 tires
do not provide adequate clearance.
²Use SAE class ªSº tire chains or traction devices only.
²Chains must be the proper size for the vehicle, as
recommended by the chain manufacturer.
²Follow tire chain manufacturer's instructions for
mounting chains.
²Install chains snugly and tighten after.6 mile (1 km) of
driving.
²Do notexceed 30 mph (48 km/h).
²Drive cautiously, avoiding large bumps, potholes and
extreme driving maneuvers.
²Do notuse chains or traction devices on the Poly-spare
tire.
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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Follow the recommended tire rotation frequency for your
type of driving found in the ªMaintenance Schedulesº
Section of this manual. More frequent rotation is permis-
sible if desired. The reasons for any rapid or unusual
wear should be corrected prior to rotation being per-
formed.
The suggested rotation method is the ªforward-crossº
shown in the following diagram.FUEL REQUIREMENTS
Your engine is designed to meet all emis-
sions regulations and provide excellent
fuel economy and performance when us-
ing high quality unleaded gasoline having
an octane rating of 87. The use of premium
gasoline is not recommended. The use of
premium gasoline will provide no benefit over high
quality regular gasoline, and in some circumstances may
result in poorer performance.
Light spark knock at low engine speeds is not harmful to
your engine. However, continued heavy spark knock at
high speeds can cause damage and immediate service is
required. Engine damage resulting from operation with a
heavy spark knock may not be covered by the new
vehicle warranty.
Poor quality gasoline can cause problems such as hard
starting, stalling and hesitations. If you experience these
symptoms, try another brand of gasoline before consid-
ering service for the vehicle.
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Over 40 auto manufacturer's world wide have issued and
endorsed consistent gasoline specifications (the World-
wide Fuel Charter, WWFC) to define fuel properties
necessary to deliver enhanced emissions, performance,
and durability for your vehicle. The manufacturer recom-
mends the use of gasoline that meets the WWFC speci-
fications if they are available.
Reformulated Gasoline
Many areas of the country require the use of cleaner
burning gasoline referred to as Reformulated Gasoline.
Reformulated gasoline contains oxygenates, and is spe-
cifically blended to reduce vehicle emissions and im-
prove air quality.
The manufacturer strongly supports the use of reformu-
lated gasoline. Properly blended reformulated gasoline
will provide excellent performance and durability for the
engine and fuel system components.
Gasoline/Oxygenate Blends
Some fuel suppliers blend unleaded gasoline with oxy-
genates such as 10% ethanol, MTBE, and ETBE. Oxygen-
ates are required in some areas of the country during thewinter months to reduce carbon monoxide emissions.
Fuels blended with these oxygenates may be used in
your vehicle.
CAUTION!
DO NOT use gasoline containing METHANOL.
Gasoline containing methanol may damage critical
fuel system components.
MMT In Gasoline
MMT is a manganese containing metallic additive that is
blended into some gasoline to increase octane. Gasoline
blended with MMT provides no performance advantage
beyond gasoline of the same octane number without
MMT. Gasoline blended with MMT reduces spark plug
life and reduces emission system performance in some
vehicles. The manufacturer recommends that gasoline
without MMT be used in your vehicle. The MMT content
of gasoline may not be indicated on the gasoline pump,
therefore, you should ask your gasoline retailer whether
or not his/her gasoline contains MMT.
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It is even more important to look for gasoline without
MMT in Canada because MMT can be used at levels
higher than allowed in the United States. MMT is pro-
hibited in Federal and California reformulated gasoline.
Sulfur In Gasoline
If you live in the northeast United States, your vehicle
may have been designed to meet California low emission
standards with clean burning, low sulfur, California
gasoline. Gasoline sold outside of California is permitted
to have higher sulfur levels which may affect the perfor-
mance of the vehicle's catalytic converter. This may cause
the ªMalfunction Indicator Lightº to illuminate.
Illumination of this light while operating on high sulfur
gasoline does not necessarily mean your emission control
system is malfunctioning. The manufacturer recom-
mends that you try a different brand of unleaded gaso-
line having lower sulfur to determine if the problem is
fuel related prior to returning your vehicle to an autho-
rized dealer for service.
CAUTION!
If the ªMalfunction Indicator Lightº is flashing,
immediate service is required. See ªOnboard Diag-
nostic Systemº in Section 7 of this manual.
Materials Added To Fuel
All gasoline sold in the United States is required to
contain effective detergent additives. Use of additional
detergents or other additives is not needed under normal
conditions.
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FUEL FILLER CAP (GAS CAP)
The fuel cap is located on the left side of the vehicle. If the
fuel cap is lost or damaged, be sure the replacement cap
is for use with this vehicle.CAUTION!
Damage to the fuel system or emission control
system could result from using an improper fuel cap
(gas cap). A poorly fitting cap could let impurities
into the fuel system. Also, a poorly fitting after-
market cap can cause the MIL (Malfunction Indica-
tor Light) to illuminate, due to fuel vapors escaping
from the system.
²Turn the engine off.
²Rotate the fuel cap to the left to remove.
²To replace the cap, insert it into the filler neck and
tighten the cap about 1/4 turn until you hear one click.
This is an indication that the cap is properly tightened.
²Make sure that the fuel cap tether strap is not caught
under the fuel cap.
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