I have a couple of friends who run their diesels on recycled cooking oil in the summer exclusively. They don't use any type of converter or heater. In the summer 100% oil just straight into the tank. In the fall they start to mix ratio's of 3/4 oil to 1/4 diesel, 1/2 to 1/2 etc until when it is cold, only diesel. They have had great success. I haven't jumped off the crazy bridge with them yet. Any other experimented with oil?