OK, I said for IDI, because I don't want this to become some kind of full fledged biodiesel conversation that belongs in another forum. I'm gonna buy one of these.... http://www.homebiodieselkits.com/hobikit.html I'd be interested to know if anybody has run biodiesel in their IDI, and what the gotcha's are. I'm tired of $3.17 a gallon, and so it's time to do something serious about it. WMO doesn't smell good. I've done the math, and this system will pay for itself in 5 months, assuming I get my "crude" for free. That's a pretty dang fast ROI, and that's for one truck alone. I have 3, and maybe soon 4.