They used left over fry grease. It was filtered (I think quite a bit from the sound of it on the show). The car got the same mileage as with PetroDiesel. Sounded rather impressive all things considered (unknown maintence requirements/firing issues, etc)

Here's an article I read a while back that holds a lot of promise for speedy and mobile production of your own diesel. I would tend to agree that ethanol is not the end all of our problems with fuel, but I think it's still needed for the diesel process as you mentioned. It will have it's place and with the flexfuel vehicles, you can switch between gas and E85. With Diesel, you can switch between Diesel and BioDiesel (and maybe Veggie oil!). Diesel isn't as easy to find as gas and BioDiesel is even harder (so is E85 for that matter). If we could manufacture our own from home grown oil stocks, farmers could sell you biodiesel! Talk about bring it back home for the working man. <img src="/images/graemlins/smile.gif" alt="" />

The other thing I'm intersted in is the new Algae feedstock for biodiesel which can be produced while it filters power plant emissions. Very cool indeed.
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Experience is a hard teacher because she gives the test first, the lesson afterwards.