Jeep Gladiator 2021, Owner'S Manual, Page: 149 / 484

STARTING AND OPERATING 147
NOTE:

Use of Climatized ULSD Fuel or Number
1 ULSD fuel results in a noticeable decrease
in fuel economy.

Climatized ULSD fuel is a blend of Number
2 ULSD fuel and Number 1 ULSD fuel which
reduces the temperature at which wax crys -
tals form in fuel.

The fuel grade should be clearly marked on
the pump at the fuel station.

The engine requires the use of “Ultra Low
Sulfur Diesel Fuel”. Use of incorrect fuel
could result in engine and exhaust system
damage
Ú
page 454.

If climatized or Number 1 ULSD fuel is not
available, and you are operating below 20°F
(-6°C), in sustained arctic conditions,
Mopar® Premium Diesel Fuel Treatment (or
equivalent) is recommended to avoid gelling
(see Fuel Operating Range Chart).
Engine Oil Usage
See Engine Fluids and Lubricants for the correct
engine oil viscosity
Ú
page 458.
Engine Warm-Up
Avoid full throttle operation when the engine is
cold. When starting a cold engine, bring the
engine up to operating speed slowly to allow the
oil pressure to stabilize as the engine warms up.
If temperatures are below 32°F (0°C), operate
the engine at moderate speeds for five minutes
before full loads are applied.
E
NGINE
I
DLING
Avoid prolonged idling, long periods of idling
may be harmful to your engine because
combustion chamber temperatures can drop so
low that the fuel may not burn completely.
Incomplete combustion allows carbon and
varnish to form on piston rings, cylinder head
valves, and injector nozzles. Also, the unburned
fuel can enter the crankcase, diluting the oil
and causing rapid wear to the engine.
S
TOPPING
T
HE
E
NGINE
After full load operation, idle the engine for a
few minutes before shutting it down. This idle
period will allow the lubricating oil and coolant
to carry excess heat away from the
turbocharger.
NOTE:
Refer to the following chart for proper engine
shutdown.
Driving Condition Load Turbocharger Temperature
Idle Time (min.) Before Engine
Shutdown
Stop and Go Empty Cool None
Stop and Go Medium 0.5
Highway Speeds Medium Warm 1.0
4