2018 JEEP WRANGLER JK engine

•Mix a minimum solution of 50% OAT engine coolant
that meets the requirements of FCA Material Standard
MS.90032 and distilled water. Use higher concentrations
(not to exceed 70%) if temperatures below 34°F (37°C)
are anticipated. Please contact an authorized dealer for
assistance.
• Use only high purity water such as distilled or deionized
water when mixing the water/engine coolant (anti-
freeze) solution. The use of lower quality water will
reduce the amount of corrosion protection in the engine
cooling system.
NOTE:
• It is the owner’s responsibility to maintain the proper
level of protection against freezing according to the
temperatures occurring in the area where the vehicle is
operated.
• Some vehicles require special tools to add coolant prop-
erly. Failure to fill these systems properly could lead to
severe internal engine damage. If any coolant is needed
to be added to the system, please contact a local autho-
rized dealer.
•
Mixing engine coolant (antifreeze) types is not recom-
mended and can result in cooling system damage. If HOAT and OAT coolant are mixed in an emergency, have
a authorized dealer drain, flush, and refill with OAT
coolant (conforming to MS.90032) as soon as possible.
Cooling System Pressure Cap
The cap must be fully tightened to prevent loss of engine
coolant (antifreeze), and to ensure that engine coolant
(antifreeze) will return to the radiator from the coolant
expansion bottle/recovery tank if so equipped.
The cap should be inspected and cleaned if there is any
accumulation of foreign material on the sealing surfaces.

•Maintain engine coolant (antifreeze) concentration at a
minimum of 50% OAT coolant (conforming to
MS.90032) and distilled water for proper corrosion pro-
tection of your engine which contains aluminum com-
ponents.
• Make sure that the coolant expansion bottle overflow
hoses are not kinked or obstructed.
• Keep the front of the radiator clean. If your vehicle is
equipped with air conditioning, keep the front of the
condenser clean.
• Do not change the thermostat for Summer or Winter
operation. If replacement is ever necessary, install ONLY
the correct type thermostat. Other designs may result in
unsatisfactory engine coolant (antifreeze) performance,
poor gas mileage, and increased emissions.
Brake System
In order to assure brake system performance, all brake
system components should be inspected periodically. Refer
to the “Maintenance Plan” in this section for the proper
maintenance intervals.

WARNING!
•Use only manufacturer’s recommended brake fluid.
Refer to “Fluids And Lubricants” in “Technical
Specifications” for further information. Using the
wrong type of brake fluid can severely damage your
brake system and/or impair its performance. The
proper type of brake fluid for your vehicle is also
identified on the original factory installed hydraulic
master cylinder reservoir.
• To avoid contamination from foreign matter or mois-
ture, use only new brake fluid or fluid that has been
in a tightly closed container. Keep the master cylin-
der reservoir cap secured at all times. Brake fluid in
a open container absorbs moisture from the air
resulting in a lower boiling point. This may cause it
to boil unexpectedly during hard or prolonged brak-
ing, resulting in sudden brake failure. This could
result in a collision.
• Overfilling the brake fluid reservoir can result in
spilling brake fluid on hot engine parts, causing the
brake fluid to catch fire. Brake fluid can also damage
painted and vinyl surfaces, care should be taken to
avoid its contact with these surfaces.
(Continued)

WARNING!
To avoid the risk of forcing the vehicle off the jack, do
not tighten the lug nuts fully until the vehicle has been
lowered. Failure to follow this warning may result in
personal injury.
FUEL REQUIREMENTS
3.6L Engine
This engine is designed to meet all emis-
sions regulations and provide excellent
fuel economy and performance when
using high-quality unleaded “Regular”
gasoline having an octane rating of 87 as
specified by the (R+M)/2 method. The
use of higher octane “Premium” gaso-
line will not provide any benefit over “Regular” gasoline in
these engines.
While operating on gasoline with an octane number of 87,
hearing a light knocking sound from the engine is not a cause for concern. However, if the engine is heard making
a heavy knocking sound, see your dealer immediately. Use
of gasoline with an octane number lower than 87 can cause
engine failure and may void or not be covered by the New
Vehicle Limited 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 consider-
ing service for the vehicle.
Reformulated Gasoline
Many areas of the country require the use of cleaner
burning gasoline referred to as “Reformulated Gasoline”.
Reformulated gasoline contains oxygenates and are specifi-
cally blended to reduce vehicle emissions and improve air
quality.
The use of reformulated gasoline is recommended. Prop-
erly blended reformulated gasoline will provide improved
performance and durability of engine and fuel system
components.