2008 JEEP WRANGLER engine

It is even more important to look for gasoline without
MMT in Canada, because MMT can be used at levels
higher than those allowed in the United States.
MMT is prohibited in Federal and California-
reformulated gasoline.
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 are not needed under
normal conditions and would result in additional cost.
Therefore you should not have to add anything to the
fuel.
Fuel System Cautions
CAUTION!
Follow these guidelines to maintain your vehicle’s
performance:
•The use of leaded gasoline is prohibited by Federal
law. Using leaded gasoline can impair engine perfor-
mance, and damage the emission control system.
•An out-of-tune engine, or certain fuel or ignition
malfunctions, can cause the catalytic converter to
overheat. If you notice a pungent burning odor or
some light smoke, your engine may be out of tune or
malfunctioning and may require immediate service.
Contact your authorized dealer for service assistance.
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•The use of fuel additives which are now being sold as
octane enhancers is not recommended. Most of these
products contain high concentrations of methanol.
Fuel system damage or vehicle performance problems
resulting from the use of such fuels or additives is not
the responsibility of the manufacturer.
NOTE: Intentional tampering with emissions control
systems can result in civil penalties being assessed
against you.
Carbon Monoxide Warnings
WARNING!
Carbon monoxide (CO) in exhaust gases is deadly.
Follow the precautions below to prevent carbon
monoxide poisoning:
•Do not inhale exhaust gases. They contain carbon
monoxide, a colorless and odorless gas which can kill.
Never run the engine in a closed area, such as a
garage, and never sit in a parked vehicle with the
engine running for an extended period. If the vehicle is
stopped in an open area with the engine running for
more than a short period, adjust the ventilation system
to force fresh, outside air into the vehicle.
•Guard against carbon monoxide with proper mainte-
nance. Have the exhaust system inspected every time
the vehicle is raised. Have any abnormal conditions
repaired promptly. Until repaired, drive with all side
windows fully open.
•Keep the swing gate closed when driving your vehicle
to prevent carbon monoxide and other poisonous
exhaust gases from entering the vehicle.
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5

CAUTION!
Damage to the fuel system or emission control sys-
tem 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 Malfunction Indicator Light
to illuminate, due to fuel vapors escaping from the
system.
CAUTION!
To avoid fuel spillage and overfilling, do not “top
off” the fuel tank after filling.
NOTE: When the fuel nozzle “clicks” or shuts off, the
fuel tank is full.
WARNING!
•Never have any smoking materials lit in or near
the vehicle when the gas cap is removed or the
tank filled.
•Never add fuel when the engine is running. This is
in violation of most state and federal fire regula-
tions and will cause the Malfunction Indicator
Light to turn on.
NOTE: Tighten the gas cap about 1/4 turn until you
hear one click. This is an indication that cap is properly
tightened.
If the gas cap is not tightened properly, the Malfunction
Indicator Light will come on. Be sure the gas cap is
tightened every time the vehicle is refueled.
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5

Engine/
Transmission Axle Model GCWR (Gross
Combined Wt.Rating) Frontal Area Max. GTW
(Gross TrailerWt.) Max. Trailer
Tongue Wt. (See Note)
3.8L/Manual 3.21 2–Door X Model (4WD)4,987 lbs
(2 262 kg) 25 sq ft
(2.32 sq m) 1,000 lbs
(453 kg) 100 lbs (45 kg)
3.8L/Manual 3.73 2–Door X Model (4WD)5,987 lbs
(2 716 kg) 25 sq ft
(2.32 sq m) 2,000 lbs
(907 kg) 200 lbs (91 kg)
3.8L/
Automatic 3.73 2–Door X
Model (4WD) 6,032 lbs
(2 736 kg) 25 sq ft
(2.32 sq m) 2,000 lbs
(907 kg) 200 lbs (91 kg)
3.8L/Manual 3.21 2–Door Sahara Model (4WD)5,163 lbs
(2 342 kg) 25 sq ft
(2.32 sq m) 1,000 lbs
(453 kg) 100 lbs (45 kg)
3.8L/Manual 3.73 2–Door Sahara Model (4WD)6,163 lbs
(2 795 kg) 25 sq ft
(2.32 sq m) 2,000 lbs
(907 kg) 200 lbs (91 kg)
3.8L/
Automatic 3.73 2–Door Sahara
Model (4WD) 6,163 lbs
(2 795 kg) 25 sq ft
(2.32 sq m) 2,000 lbs
(907 kg) 200 lbs (91 kg)
3.8L/Manual 4.10 2–Door Rubi- con Model(4WD) 6,236 lbs
(2 829 kg) 25 sq ft
(2.32 sq m) 2,000 lbs
(907 kg) 200 lbs (91 kg)
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5

WARNING!
Improper towing can lead to an injury accident.
Follow these guidelines to make your trailer towing
as safe as possible:
Make certain that the load is secured in the trailer
and will not shift during travel. When trailering
cargo that is not fully secured, dynamic load shifts
can occur that may be difficult for the driver to
control. You could lose control of your vehicle and
have an accident.
•When hauling cargo or towing a trailer, do not over-
load your vehicle or trailer. Overloading can cause a
loss of control, poor performance or damage to brakes,
axle, engine, transmission, steering, suspension, chas-
sis structure or tires.
•Safety chains must always be used between your
vehicle and trailer. Always connect the chains to the
frame or hook retainers of the vehicle hitch. Cross the
chains under the trailer tongue and allow enough
slack for turning corners.
•Vehicles with trailers should not be parked on a grade.
When parking, apply the parking brake on the tow
vehicle. Put the tow vehicle automatic transmission in
PARK. With a manual transmission, shift the transmis-
sion into 1st gear. And with four-wheel-drive vehicles,
make sure the transfer case is not in N (Neutral).
Always, block orchockthe trailer wheels.
•GCWR must not be exceeded.
•Total weight must be distributed between the tow
vehicle and the trailer such that the following four
ratings are not exceeded:
1. GVWR
354 STARTING AND OPERATING

If using a manual transmission vehicle for trailer towing,
all starts must be in 1st gear to avoid excessive clutch
slippage.
Towing Tips — Automatic Transmission
The DRIVE range can be selected when towing. How-
ever, if frequent shifting occurs while in this range, the
OVERDRIVE range should be selected.
NOTE:Using “O/D OFF” while operating the vehicle
under heavy operating conditions will improve perfor-
mance and extend transmission life by reducing exces-
sive shifting and heat build up. This action will also
provide better engine braking.
The automatic transmission fluid and filter should be
changed if you REGULARLY tow a trailer for more than
45 minutes of continuous operation. Refer to the “Main-
tenance Schedule” in Section 8 of this manual for trans-
mission fluid change intervals. NOTE:
Check the automatic transmission fluid level
before towing.
Towing Tips — O/D Off
To reduce potential for automatic transmission overheat-
ing, select the “O/D OFF” feature when driving in hilly
areas or shift the transmission to DRIVE position 2 on
more severe grades. Refer to “Transmission Shifting” in
this section.
Towing Tips — Electronic Speed Control (If
Equipped)

Don’t use in hilly terrain or with heavy loads.
When using the speed control, if you experience speed
drops greater than 10 mph (16 km/h), disengage until
you can get back to cruising speed.
Use speed control in flat terrain and with light loads to
maximize fuel efficiency.
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Towing Tips — Cooling System
To reduce potential for engine and transmission over-
heating, take the following actions:
Highway Driving
Reduce speed.
Air Conditioning
Turn off temporarily.
refer to Cooling System Operating information in the
Maintenance section of this manual for more informa-
tion.
RECREATIONAL TOWING (BEHIND
MOTORHOME, ETC.)
CAUTION!
Front or rear wheel lifts should not be used. Internal
damage to the transmission or transfer case will occur
if a front or rear wheel lift is used when recreational
towing.
Towing – 2WD Models
Recreational towing is allowed ONLY if the rear drive-
shaft is removed. See your authorized dealer or refer to
the Service Manual. Towing with the rear wheels on the
ground while the driveshaft is connected can result in
severe transmission damage.
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5

Towing – 4WD Models
NOTE:The transfer case must be shifted into N (Neu-
tral) for recreational towing.
Shifting Into Neutral (N)
Use the following procedure to prepare your vehicle for
recreational towing.
CAUTION!
It is necessary to follow these steps to be certain that
the transfer case is fully in N (Neutral) before recre-
ational towing to prevent damage to internal parts.
1. Depress brake pedal.
2. Shift automatic transmission into NEUTRAL or de-
press clutch pedal on manual transmission.
3. Shift transfer case lever into N (Neutral). 4. Start engine.
5. Shift automatic transmission into DRIVE or manual
transmission into gear.
6. Release brake pedal and ensure that there is no vehicle
movement.
7. Shut the engine off and place the ignition key into the
ACC position.
8. Shift automatic transmission into PARK.
9. Apply parking brake.
10. Attach vehicle to the tow vehicle with tow bar.
11. Release parking brake.
12. Disconnect the negative battery cable, and secure it
away from the negative battery post.
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