OK. A very brief explanation: The truck has 2 tanks, 1 for diesel (factory) one for veggie (aluminum where spare tire was). The veggie tank is heated by coolant that flows back to the veggie tank, goes through a loop and warms the veggie, there are 2 separate fuel filters the veggie one is heated, there are 3 valves that are electrically controlled that choose which tank to pull from, which fuel filter to feed, and the third controls the flush cycle. There is also a flatplate heat exchanger, a # of temp sensors, and the "brain" which controls it all and shows temps, fuel level, etc.
So basically I start the truck on diesel, drive until my coolant temp is 158 degrees, switch to veggie, drive as long as I want, before I get to my destination and shut the truck off, I switch back to diesel and purge the veggie out of the system before I shut off. I also have a filtration system built at home which filters and de-waters the fuel down to 5 microns. It all sounds good on paper and I can attest that it works, but it is not fool proof, its messy, time consuming, filters clog, fuel line blow and leak and like I said before filtering on the road is very difficult.
My wife thinks its all cool and wants me to do a system on a TDI VW Passat for her. We have talked about it and I am not sure I want to deal with it, the VW's are a little more sensitive than a 12 valve, I could see her forgetting to purge and the whole car gelling up, I work 48 hr shifts at a fire dept and if she breaks down from a clog or a blown line I can't leave and go help her. I think she's going to run her 97 Subaru for a bit longer and I want to convert a Toyota pickup with some (yet to be determined) diesel that she can drive also, but not totally rely on.
If you're thinking about it, do a lot of reading, make sure you can find veggie sources and seriously consider which vehicle you want to use, most of the newer diesels don't respond as well as the older ones.
