JEEP WRANGLER 2008 JK / 3.G Owners Manual

ADDING FUEL
Fuel Filler Cap (Gas Cap)
The gas cap is located on the driver’s side of the vehicle.
If the gas cap is lost or damaged, be sure the replacement
cap is the correct one for this vehicle.
Loose Fuel Filler Cap Message (gASCAP)
After fuel has been added, the vehicle diagnostic system
can determine if the fuel filler cap is possibly loose,
improperly installed, or damaged. If the system detects a
malfunction, the “gASCAP” message will display in the
odometer display. Tighten the gas cap until aclicking
sound is heard. This is an indication that the gas cap is
properly tightened. Press the odometer reset button to
turn the message off. If the problem persists, the message
will appear the next time the vehicle is started. This
might indicate a damaged cap. If the problem is detected
twice in a row, the system will turn on the Malfunction
Indicator Light. Resolving the problem will turn the MIL
light off.
Fuel Filler Cap
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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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WARNING!
A fire may result if gasoline is pumped into a
portable container that is inside of a vehicle. You
could be burned. Always place gas containers on the
ground while filling.
VEHICLE LOADING
Certification Label
As required by National Highway Traffic Safety Admin-
istration regulations, your vehicle has a certification label
affixed to the driver’s side door or B-Pillar.
This label contains the month and year of manufacture,
Gross Vehicle Weight Rating (GVWR), Gross Axle Weight
Rating (GAWR) front and rear, and Vehicle Identification
Number (VIN). A Month-Day-Hour (MDH) number isincluded on this label and indicates the month, day, and
hour of manufacture. The bar code that appears on the
bottom of the label is your VIN.
Gross Vehicle Weight Rating (GVWR)
The GVWR is the total permissible weight of your vehicle
including driver, passengers, vehicle, options, trailer
tongue weight, and cargo. The label also specifies maxi-
mum capacities of front and rear axle systems (GAWR).
Total load must be limited, so GVWR, and front and rear
GAWR are not exceeded.
Payload
The payload of a vehicle is defined as the allowable load
weight a truck can carry, including the weight of the
driver, all passengers, options and cargo.
Gross Axle Weight Rating (GAWR)
The GAWR is the maximum permissible load on the front
and rear axles. The load must be distributed in the cargo
area so that the GAWR of each axle is not exceeded.
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Each axle’s GAWR is determined by the components in
the system with the lowest load carrying capacity (axle,
springs, tires, or wheels). Heavier axles or suspension
components, sometimes specified by purchasers for in-
creased durability, does not necessarily increase the ve-
hicle’s GVWR.
Tire Size
The tire size on the label represents the actual tire size on
your vehicle. Replacement tires must be equal to the load
capacity of this tire size.
Rim Size
This is the rim size that is appropriate for the tire size
listed.
Inflation Pressure
This is the cold tire inflation pressure for your vehicle for
all loading conditions up to full GAWR.
Curb Weight
The curb weight of a vehicle is defined as the total weight
of the vehicle with all fluids, including vehicle fuel, at full
capacity conditions, and with no occupants or cargo
loaded into the vehicle. The front and rear curb weight
values are determined by weighing your vehicle on a
commercial scale before any occupants or cargo are
added.
Loading
The actual total weight and the weight of the front and
rear of your vehicle at the ground can best be determined
by weighing it when it is loaded and ready for operation.
The entire vehicle should first be weighed on a commer-
cial scale to ensure that the GVWR has not been ex-
ceeded. The weight on the front and rear of the vehicle
should then be determined separately to be sure that the
load is properly distributed over front and rear axle.
Weighing the vehicle may show that the GAWR of either
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the front or rear axles has been exceeded, but the total
load is within the specified GVWR. If so, weight must be
shifted from front to rear, or rear to front, as appropriate
until the specified weight limitations are met. Store the
heavier items down low and be sure that the weight is
distributed equally. Stow all loose items securely before
driving.
Improper weight distributions can have an adverse affect
on the way your vehicle steers and handles, and the way
the brakes operate.CAUTION!
Do not load your vehicle any heavier than the GVWR
or the maximum front and rear GAWR. If you do,
parts on your vehicle can break, or it can change the
way your vehicle handles. This could cause you to
lose control. Also, overloading can shorten the life of
your vehicle.
TRAILER TOWING
In this section you will find safety tips and information
on limits to the type of towing you can reasonably do
with your vehicle. Before towing a trailer carefully re-
view this information to tow your load as efficiently and
safely as possible.
To maintain warranty coverage, follow the requirements
and recommendations in this Owner’s Manual concern-
ing vehicles used for trailer towing.
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Common Towing Definitions
The following trailer towing-related definitions will as-
sist you in understanding the following information:
Gross Vehicle Weight Rating (GVWR)
The GVWR is the total allowable weight of your vehicle.
This includes driver, passengers, cargo and trailer tongue
weight. The total load must be limited so that you do not
exceed the GVWR.
Gross Trailer Weight (GTW)
The GTW is the weight of the trailer plus the weight of all
cargo, consumables and equipment (permanent or tem-
porary) loaded in or on the trailer in itsloaded and
ready for operation condition. The recommended way to
measure GTW is to put your fully-loaded trailer on a
vehicle scale. The entire weight of the trailer must be
supported by the scale.
Gross Combination Weight Rating (GCWR)
The GCWR is the total permissible weight of your vehicle
and trailer when weighed in combination. (Note that
GCWR ratings include a 150 lbs (68 kg) allowance for the
presence of a driver).
Gross Axle Weight Rating (GAWR)
The GAWR is the maximum capacity of the front and rear
axles. Distribute the load over the front and rear axles
evenly. Make sure that you do not exceed either front or
rear GAWR.
WARNING!
It is important that you do not exceed the maximum
front or rear GAWR. A dangerous driving condition
can result if either rating is exceeded. You could lose
control of the vehicle and have an accident.
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Trailer Tongue Weight (TW)
The trailer tongue weight is the downward force exerted
on the hitch ball by the trailer. In most cases it should not
be less than 10% or more than 15% of the trailer load. You
must consider this as part of the load on your vehicle.
Frontal Area
The frontal area is the maximum height and maximum
width of the front of a trailer.
Trailer Sway Control
The trailer sway control is a telescoping link that can be
installed between the hitch receiver and the trailer
tongue. It typically provides adjustable friction associ-
ated with the telescoping motion to dampen any un-
wanted trailer swaying motions while traveling.
Weight-Carrying Hitch
A weight-carrying hitch supports the trailer tongue
weight, just as if it were luggage located at a hitch ball or
some other connecting point of the vehicle. This kind ofhitch is the most popular on the market today and is
commonly used to tow small and medium-sized trailers.
Weight-Distributing Hitch
A weight-distributing hitch system works by applying
leverage through spring (load) bars. It is typically used
for heavier loads, to distribute trailer tongue weight to
the tow vehicle’s front axle and the trailer axle(s). When
used in accordance with the manufacturers’ directions, it
provides for a more level ride, offering more consistent
steering and brake control thereby enhancing towing
safety. The addition of a friction/hydraulic sway control
also dampens sway caused by traffic and crosswinds,
and contributes positively to tow vehicle and trailer
stability. Trailer sway control and a weight-distributing
(load-equalizing) hitch are recommended for heavier
tongue weights (TW) and may be required depending on
vehicle and trailer configuration/loading to comply with
Gross Axle Weight Rating (GAWR) requirements.
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WARNING!
An improperly adjusted weight-distributing hitch
system may reduce handling, stability, braking per-
formance, and could result in an accident.
Weight-Distributing Hitch Systems may not be com-
patible with Surge Brake Couplers. Consult with
your hitch and trailer manufacturer or a reputable
Recreational Vehicle dealer for additional
information.
Weight-Distributing Hitch System
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Trailer Hitch Classification
The following chart provides the industry standard for
the maximum trailer weight a given trailer hitch class can
tow and should be used to assist you in selecting the
correct trailer hitch for your intended towing condition.Refer to the Trailer Towing Weights (Maximum Trailer
Weight Ratings) chart for the Max. GTW towable for your
given drivetrain.
Trailer Hitch Classification
Class Max. GTW (Gross Trailer Wt.)
Class I - Light Duty 2,000 lbs (907 kg)
Class II - Medium
Duty 3,500 lbs (1 587 kg)
All trailer hitches should be professionally installed on
your vehicle.
Trailer Towing Weights (Maximum Trailer Weight
Ratings)
The following chart provides the maximum trailer
weight ratings towable for your given drivetrain.
Improper Adjustment of Weight-Distributing System
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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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