JEEP WRANGLER UNLIMITED 2013 Owners Manual

can be used at levels higher than those allowed in the
United States. MMT is prohibited in Federal and Califor-
nia 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 is not needed under normal conditions
and they 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 gas is prohibited by Federal law.
Using leaded gasoline can impair engine perfor-
mance and damage the emissions control system. (Continued) CAUTION! (Continued)• 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.
• The use of fuel additives, which are now being sold
as octane enhancers, is not recommended. Most of
these products contain high concentrations of metha-
nol. Fuel system damage or vehicle performance
problems resulting from the use of such fuels or
additives is not the responsibility of the manufac-
turer.
NOTE: Intentional tampering with the emissions control
system can result in civil penalties being assessed against
you.
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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. (Continued) WARNING! (Continued)• Guard against carbon monoxide with proper main-
tenance. 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.
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.510 STARTING AND OPERATING

CAUTION!• Damage to the fuel system or emission control
system could result from using an improper fuel (Continued) CAUTION! (Continued)cap (gas cap). A poorly fitting cap could let impu-
rities into the fuel system. Also, a poorly fitting
aftermarket cap can cause the “Malfunction Indi-
cator Light (MIL)” to illuminate, due to fuel vapors
escaping from the system.
• To avoid fuel spillage and overfilling, do not “top
off” the fuel tank after filling.
WARNING!• Never have any smoking materials lit in or near the
vehicle when the gas cap is removed or the tank is
being filled.
• Never add fuel when the engine is running. This is
in violation of most state and federal fire regula-
tions and may cause the MIL to turn on. (Continued)Fuel Filler Cap
5 STARTING AND OPERATING 511

WARNING! (Continued)• 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.
NOTE:
• When the fuel nozzle “clicks” or shuts off, the fuel tank
is full.
• Tighten the gas cap about 1/4 turn until you hear one
click. This is an indication that the cap is properly
tightened.
• If the gas cap is not tightened properly, the MIL will
come on. Be sure the gas cap is tightened every time
the vehicle is refueled. Loose Fuel Filler Cap Message
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 a  clicking 
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 MIL. Resolving
the problem will turn the MIL off.512 STARTING AND OPERATING

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 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 is
included 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 and cargo.
The label also specifies maximum 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.
Each axle 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 vehi-
cle’s GVWR.
5 STARTING AND OPERATING 513

Tire Size
The tire size on the Vehicle Certification 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 insure that the GVWR has not been exceeded.
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 the front and rear axle. Weigh-
ing the vehicle may show that the GAWR of either 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 heavier514 STARTING AND OPERATING

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 effect
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
review this information to tow your load as efficiently
and safely as possible.
To maintain warranty coverage, follow the requirements
and recommendations in this manual concerning ve-
hicles used for trailer towing.
Common Towing Definitions
The following trailer towing related definitions will assist
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 tongue
weight. The total load must be limited so that you do not
5 STARTING AND OPERATING 515

exceed the GVWR. Refer to “Vehicle Loading/Vehicle
Certification Label” in “Starting and Operating” for
further information.
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 its  loaded 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: The GCWR rating includes 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. Refer to “Vehicle Loading/Vehicle Certification
Label” in “Starting and Operating” for further information.
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 a collision.
Tongue Weight (TW)
The 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.516 STARTING AND OPERATING

Frontal Area
The frontal area is the maximum height multiplied by the
maximum width of the front of a trailer.
Trailer Sway Control – If Equipped
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. These kinds
of hitches are the most popular on the market today and
they are commonly used to tow small- and medium-
sized trailers. Weight-Distributing Hitch
A weight-distributing system works by applying lever-
age through spring (load) bars. They are 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 manufacturer’s directions, it pro-
vides 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
performance, and could result in a collision.
• Weight Distributing Systems may not be compatible
with Surge Brake Couplers. Consult with your hitch
and trailer manufacturer or a reputable Recreational
Vehicle dealer for additional information.
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. Trailer Hitch Classification Definitions
Class Max. Trailer Hitch
Industry Standards
Class I - Light Duty 2,000 lbs (907 kg)
Class II - Medium Duty 3,500 lbs (1 587 kg)
Class III - Heavy Duty 5,000 lbs (2 268 kg)
Class IV - Extra Heavy
Duty 10,000 lbs (4 540 kg)
Refer to the “Trailer Towing Weights (Maximum
Trailer Weight Ratings)” chart for the Maximum
Gross Trailer Weight (GTW) towable for your given
drivetrain.
All trailer hitches should be professionally installed
on your vehicle.518 STARTING AND OPERATING