We've been making biodiesel for about 7 months now and we're up to around 170 gallons. We've run the '84 Mercedes "bitty" wagon over 2500 miles on this renewable, clean-burning fuel.
The process isn't anywhere near as difficult as you'd think, and you'll recognize how much wasteful driving is done when you're actually responsible for producing the fuel that you use! I'll be detailing the process on http://theseep.com
in upcoming months, but essentially, with a used hot water heater, a pump, some plumbing and a bit of elbow grease (literally and figuratively), you can make your own clean-burning fuel at home. After an initial investment of around $1000 (you can do this MUCH cheaper - I bought a new water heater and had to build a small shed. Plenty of used and cheap parts can be found and scavenged through craig's list, ebay, and other sources to bring the cost down), the fuel costs around $1.50/gallon to make plus a few hours of time for every 30 gallon batch. The only costs are the methanol (the cheapest I've found locally is at J.B. Dewar's in SLO at $216 for a 55 gallon barrel, which makes 275 gallons of biodiesel) and the KOH (potassium hydroxide) and some maintenance here and there. We're planning on upgrading to a VW Golf TDI which gets around 50 mpg!http://www.localb100.com/
is a great place to start. Maria Alovert, mother of the "appleseed processor" is a regular poster in the forums and a wealth of knowledge for questions. I attended one of her seminars last year at Four Elements Herb Farm in Atascadero, CA and it really got me going and I've been up and running since. A friend that I met there, Rich Tao, DVM has since converted his diesel truck to SVO (straight vegetable oil) and he's been driving on completely free used oil!