Brulen, I’ve only used biodiesel once, but it seemed to yield slightly more power and mileage. Still, I’ve been warned that long term use requires rubber supply lines to be of a compound specifically made for that fuel. I’ve also read that clean vegetable oil, or well-filtered used veg. oil will work, as long as it is warm (usually heated by a line from the engine cooling system routed through the tank) enough to be liquid of approximately the same viscosity as diesel. I’ve never tried that myself, but I’ve talked to a few “greasecar” owners who were satisfied with the mileage they were getting for the cost (usually just labor) of gathering it from restaurants, filtering, and storing it.