Never thought I would see this on ar15.com! Back in college I was really in to renewables. As an engineering project we ran a conventional gas engine on a form of ethanol we cooked up ourselves. At the time I was working as a diesel mechanic while in school. I had a boss that was the master of diesel mechs, and he showed how you could actually run a diesel on refined milk!!! Apparently it is the high fat content in bio fuels that is important. I bought an old Volkswagon Rabbit that had a diesel in it and ran it on a mix of WVO and my own home brewed ethanol. My WVO mix was so poor I had to add ethanol in it to get it going. One of the problems with this using WVO is that companies actually contract to buy the stuff for use in other things, so it is hard to get believe or not. Was for me anyway. Eventually mixing the fuels ruined the engine in the old Rabbit. Hadn't thought about that stuff in a while. I really enjoyed doing that project, I am not much of a tree hugger but I like doing my own thing. If I can find my old college engineering notes I will email them to you. Lot of good info.