TM-5-4310-389-14
Section IV.
OPERATING UNDER UNUSUAL CONDITIONS
2-14 OPERATION IN EXTREME COLD.
NOTE
When operating the K-20 in cold weather 320F (00C) or below, both the
engine and compressor lubricating oils must be changed to cold weather
oils.
To ensure satisfactory cold starting, the choice of the viscosity grade should be governed by the ambient temperature
prevailing at the time of starting. As to the oil change intervals, it should be kept in mind that operation below 50'F
(100C) requires shorter oil change intervals.
Use winter-grade fuel in winter because, with ordinary fuel, waxing may occur at low temperatures and clog the fuel filter.
At excessively low temperatures, even winter-grade fuel may tend to wax. Therefore, if only summer-grade fuel is
available, or if winter-grade fuel is used at excessively low temperatures, the following percentages are recommended
(figure 2-16) for mixtures of diesel fuel and kerosene or regular-grade gasoline.
Figure 2-16. Fuel Mixture by Temperature
Prepare the blend in the tank itself: fill in the gasoline first, then add diesel fuel. The blend is as easily flammable as
pure gasoline. A mixture of the latter, however, is permissible for a short period only, but never for permanent operation.
2-19
