Diesel engines can run on a lot of different fuels... I checked into the biodiesel bit, and while I love it for a SHTF purpose, it just doesn't seem to be practical from a per gallon cost perspective. The only way it is, is if you can actually get quality used cooking oil for free, from a restaurant. Sadly, this is largely a thing of the past, as now most can actually SELL this to companies doing much the same thing for their own vehicles. They do sell starter kits, but in my own research, the per gallon savings, for the work involved, just isn't worth it. Not to mention, you'll need two tanks for most applications. One with regular diesel fuel, and one with the biodiesel. You'll need to use the diesel fuel to start the engine, then have a heater to ensure the biodiesel is liquid before switching to that tank. My truck already has a three tank setup, and even I decided the cost just isn't worth it to do now. (though I would like to have the starter kit for a SHTF scenario).