http://en.wikipedia.org/wiki/Biodiesel Intresting read. We have been selling Diesel from our rural filling station for a couple of years now and had to have our fuel tanks check for the presents of water from condensation in our fuel tanks as the Bio Diesel will bring the water from the bottom of the tanks with it. Also be aware that you should be using a barrier type fuel hose now as the Bio Diesel degrade rubber. Look it up on the internet...........