Good morning all. The reason you preheat WMO or WVO is purely for viscosity reasons and what kind of IP you run. Our wonderful(read sarcasm) little idi pumps won't handle a wide variation in viscosity. A guy in Abilene is running straight WMO in a P-pumped 12v with no heater ... has been for three years now with no issues, but our pumps won't do this! I've been running straight crude oil in mine since march and have even unhooked my glow plugs because it starts and runs so much better. My crude (API 44 gravity) still has all the good stuff in it that the refineries take out to make gas and stuff. I've even put some oil samples in the frig and the freezer to run viscosity checks in prep for the upcoming winter .... it'll be fine without any preheat other than naturally occurring heat under the hood. There are remote oilfields around OK and KS that run huge CAT generators on pretty thick (API 18-25 grav.) field oil for their electricity. These engines require the crude to be preheated to 120-160 deg. before the fuel system will efficiently handle it. It doesn't really have any effect on atomization. Once fuel oil will pump, it comes out of the injectors in the same metered amount. In really cold climates, you'll want to run a separate diesel tank for starting and shutdown if you're running a really stout WMO percentage(or just switch tanks on our duel tank trucks). Now a cold air intake will make a huge difference because you Can increase the density of your charge air, but not really so on the fuel system. Hope some of this helps.
