Volvo VNL Operator's Manual page 259

254 Engine Start and Operation
Oil Pan Heater (option)
Oil pan heaters aid low temperature starting
by improving oil flow to critical parts in
the engine. This helps prevent engine wear.
They are similar to block heaters and are
wired into the same plug as the engine
coolant heater.
Fuel Heater Filter (option)
If running in very cold weather, a heated
fuel filter should be added. A number of
different fuel heaters are available as op-
tions. They are electrically heated and
regulated by a thermostat. They are typi-
cally built into the primary fuel filter
housing.
W2001067
Fuel Tank Heater (option)
An in-tank fuel heater is also available. In-
tank heaters use hot engine coolant to
warm the fuel. This prevents wax formation
in the fuel during cold season operation.
These heaters are thermostatically con-
trolled and will automatically raise the fuel
temperature to an optimum level.