There was a story in the Detroit News about car diesels using vegetable oil
obtained from local restaurants. You have to start the engine with diesel
fuel but when the vegetable oil gets heated to where it's thin enough you
switch over to the vegetable oil. The story said that the restaurants are
glad to give it away for free so they don't have to pay to have it hauled
away. The first image I got was a piece of French Fry getting into the
injector. The story didn't mention any filtering of the vegetable oil. I
think I'd have to hear a lot of favorable first hand reports before I'd
think of trying this. Exhaust fumes would be different though.
Paul