I know a guy that bought a diesel car and for about $800 added a tank that holds veggie oil from fast food places. With the cost of filters it costs him about $.13 a gallon. It seems like this might be a little more expensive at first but could pay off. Trucks could be run on veggie oil and I wonder if a mower could be converted as well. The engine still needs to start and stop on diesel but otherwise can run on the veggie oil. It seems like it could be saving us $100 or more a week which would seem huge. Anyone else seen heard of this? There was another car on CNN yesterday that someone convereted to run on the veggie oil as well.