Some of the Shermans had aircraft engines in them and on airplanes they would add gasoline to the oil while the engine was still hot to make the oil really thin so the engine would turn over in the cold. After it started the gas would burn or evaporate off and the oil would be it's normal weight.
I do not know if they did the same for the diesel powered shermans. Don't know much about diesel but I bet T.A. has a Dodge turbo diesel in his driveway or at least wants one. It fits his personility.
