RAM 2500 2020 Owner's Manual page 227

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. Refer to "Fuel Requirements" in
"Technical Specifications" for further infor-
mation.
If climatized or diesel 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).
Under some circumstances increased engine

noise may be audible in the seconds
following a cold start. This is most likely to
occur when using fuel that isn't blended for
the ambient temperature present. This may
occur on an unseasonably cold day or when a
truck is fueled in a warmer climate and driven
to a colder climate. The noise can typically be
prevented by using Mopar Premium Diesel
Fuel Treatment as recommended (see Fuel
Operating Range Chart).
Engine Oil Usage
Refer to "Dealer Service" in "Servicing And
Maintenance" for the correct engine oil
viscosity.
Winter Front Cover Usage
A Winter front or cold weather cover is to be
used in ambient temperatures below 32°F
(0°C), especially during extended idle
conditions. This cover is equipped with four
flaps for managing total grille opening in varying
ambient temperatures. If a Winter front or cold
weather cover is to be used the flaps should be
left in the full open position to allow air flow to
the charge air cooler and automatic
transmission oil cooler. When ambient
temperatures drop below 0°F (-17°C) the four
flaps need to be closed. A suitable cold weather
cover is available from your Mopar dealer.
Battery Blanket Usage
A battery loses 60% of its cranking power as the
battery temperature decreases to 0°F (-18°C).
For the same decrease in temperature, the
engine requires twice as much power to crank
at the same RPM. The use of 120 VAC powered
battery blankets will greatly increase starting
STARTING AND OPERATING
capability at low temperatures. Suitable battery
blankets are available from an authorized
Mopar dealer.
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.
NOTE:
High-speed, no-load running of a cold engine
can result in excessive white smoke and poor
engine performance. No-load engine speeds
should be kept under 1,000 RPM during the
warm-up period, especially in cold ambient
temperature conditions.
Your vehicle is equipped with an engine warm
up protection feature that may limit engine
performance after cold starting at low ambient
temperatures. The length of time engine speed
is limited is dependent upon engine coolant
temperature. Engine speed may be briefly
limited to 1000 RPM after starting with coolant
temperature below freezing conditions, and
may be limited to 1000 RPM for up to
approximately 2 minutes under more severe
cold conditions.
225
5