This is where personal bio-diesel starts to lose me. That’s $3400 worth of stuff, assuming you get the heater, which I imagine is pretty important if you want this to work during our winters. For $3400 I can buy 1133 gallons of $3/gal gasoline and at 20 mpg that gets me almost 22700 miles. That’s almost 2 years of driving on just the initial hardware cost, not even factoring the cost of materials and your time to make the stuff. My time is worth a lot to me, so I really like the ease of being able to stop on any street corner and fill up my tank, not having to worry about if I collected enough used cooking oil this week or not.