2008 JEEP WRANGLER inflation pressure

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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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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Follow the recommended tire rotation frequency for your
type of driving. Refer to the “Maintenance Schedule” in
Section 8 of this manual. More frequent rotation is
permissible if desired. The reasons for any rapid or
unusual wear should be corrected prior to rotation being
performed.
The suggested rotation method is the “forward-cross”
shown in the following diagram.TIRE PRESSURE MONITOR SYSTEM (TPMS)
The Tire Pressure Monitoring System (TPMS) will warn
the driver of a low tire pressure based on the vehicle
recommended cold placard pressure.
The tire pressure will vary with temperature by about 1
psi (6.9 kPa) for every 12°F (6.5°C). This means that when
the outside temperature decreases, the tire pressure will
decrease. Tire pressure should always be set based on
cold inflation tire pressure. This is defined as the tire
pressure after a vehicle has not been driven for more than
three hours, or driven less than 1 mi (1 km) after a three
hour period.Refer to the “Tires — General Informa-
tion” in this section for information on how to properly
inflate the vehicle’s tires. The tire pressure will also
increase as the vehicle is driven, this is normal and there
should be no adjustment for this increased pressure.
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CAUTION!
The TPMS has been optimized for the original
equipment tires and wheels. TPMS pressures have
been established for the tire size equipped on your
vehicle. Undesirable system operation or sensor
damage may result when using replacement equip-
ment that is not of the same size, type, and/or style.
Aftermarket wheels can cause sensor damage. Do not
use aftermarket tire sealants or balance beads if your
vehicle is equipped with a TPMS, as damage to the
sensors may result.
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.
NOTE:
•The TPMS is not intended to replace normal tire care
and maintenance, nor to provide warning of a tire
failure or condition.
•The TPMS should not be used as a tire pressure gauge
while adjusting your tire pressure.
•Driving on a significantly under-inflated tire causes
the tire to overheat and can lead to tire failure.
Under-inflation also reduces fuel efficiency and tire
tread life, and may affect the vehicle’s handling and
stopping ability.
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•The TPMS is not a substitute for proper tire mainte-
nance, and it is the driver ’s responsibility to maintain
correct tire pressure, even if under-inflation has not
reached the level to trigger illumination of the Tire
Pressure Monitoring Telltale Light.
•Seasonal temperature changes will affect tire pressure,
and the TPM System will monitor the actual tire
pressure in the tire.
Base System
The Tire Pressure Monitor System (TPMS) uses wireless
technology with wheel rim-mounted electronic sensors to
monitor tire pressure levels. Sensors, mounted to each
wheel as part of the valve stem, transmit tire pressure
readings to the Receiver Module.
NOTE:It is particularly important, for you to check the
tire pressure in all of your tires regularly and to maintain
the proper pressure. The Tire Pressure Monitor System (TPMS) consists of the
following components:
•Receiver Module
•Four Tire Pressure Monitoring Sensors
•Tire Pressure Monitoring Telltale Light
A tire pressure monitoring sensor is located in the spare
wheel if the vehicle is equipped with a matching full size
spare wheel and tire assembly. The matching full size
spare tire can be used in place of any of the four road
tires. A low spare tire will not cause the Tire Pressure
Monitoring Telltale Light to illuminate or the chime to
sound. The Tire Pressure Monitoring Telltale Light will
illuminate in the instrument cluster, and an au-
dible chime will be activated when one or more of
the four active road tire pressures are low. Should this
occur, you should stop as soon as possible, check the
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inflation pressure of each tire on your vehicle, and inflate
each tire to the vehicle’s recommended cold placard
pressure value. The system will automatically update
and the Tire Pressure Monitoring Telltale Light will
extinguish once the updated tire pressures have been
received. The vehicle may need to be driven for up to 10
minutes above 15 mph (25 km/h) to receive this infor-
mation.
The Tire Pressure Monitoring Telltale Light will flash on
and off for 75 seconds, and will remain on solid when a
system fault is detected. The system fault will also sound
a chime. If the ignition key is cycled, this sequence will
repeat, providing the system fault still exists. A system
fault can occur by any of the following scenarios:
1. Jamming due to electronic devices or driving next to
facilities emitting the same Radio Frequencies as the TPM
sensors.
2. Installing some form of aftermarket window tinting
that affects radio wave signals.3. Lots of snow or ice around the wheels or wheel
housings.
4. Using tire chains on the vehicle.
5. Using wheels/tires not equipped with TPM sensors.
NOTE:
If your vehicle is equipped with a matching
full-size spare wheel and tire assembly, it has a tire
pressure monitoring sensor, and can be monitored by the
Tire Pressure Monitoring System (TPMS). In the event
that the matching full-size spare tire is swapped with a
low pressure road tire, the next ignition key cycle will
still show the Tire Pressure Monitoring Telltale Light to
be ON, and a chime to sound. Driving the vehicle for up
to 10 minutes above 15 mph (25 km/h) will turn OFF the
Tire Pressure Monitoring Telltale Light as long as none of
the road tires are below the low pressure warning thresh-
old.
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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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2. GTW
3. GAWR
4. Tongue weight rating for the trailer hitch utilized
(This requirement may limit the ability to always
achieve the 10% to 15% range of tongue weight as a
percentage of total trailer weight).
Towing Requirements — Tires

Do not attempt to tow a trailer while using a compact
spare tire.
Proper tire inflation pressures are essential to the safe
and satisfactory operation of your vehicle. Refer to the
“Tires–General Information” section of this manual for
proper tire inflation procedures.
Also, check the trailer tires for proper tire inflation
pressures before trailer usage.
Check for signs of tire wear or visible tire damage
before towing a trailer. Refer to the “Tires–General
Information” section of this manual for the proper
inspection procedure.
When replacing tires, refer to the “Tires–General Infor-
mation” section for proper tire replacement proce-
dures. Replacing tires with a higher load carrying
capacity will not increase the vehicle’s GVWR and
GAWR limits.
Towing Requirements — Trailer Brakes

Donot interconnect the hydraulic brake system or
vacuum system of your vehicle with that of the trailer.
This could cause inadequate braking and possible
personal injury.
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