I've made my own bio-diesel, but it's a pain on the road, and we also are trying to convert to veggie oil. Our vehicle is a 1995 with a computerized injection system, and not many people think conversion is possible for us. But anyway, the oil is out there, yes, we take it from grease-traps behind restaurants. No, KFC and fast food are a pain in the ass. Gotta filter it too much, cook off water most of the time and for making biodiesel, it requires more lye. Thai and chinese places are the best. I tried going in and asking for it, but my choice of oriental restaurants usually meant there'd be a language barrier. They say yes when they know what I'm talking about, so I just take it. One good restaurant should fill the tank. Don't get too worked up about the quality though. Long as it's not black and you filter it well you'll be good to go. If you are stationary and not travelling like us, you can make a deal with restaurants. they pay to have it hauled away, so they will gladly let you take it, especially if you are willing to drain it out of the fryer yourself (which insures that you can filter it while it's still warm. a real bonus) For larger amounts, I hear potato chip factories are the way to go, but i never looked into it.
The last time I saw Papabear and his family, they showed me a basket full of empty cooking oil bottles and told me the only way they made it into town was by dumping it all in the tank. And it worked for them, without conversion. they were so proud...
That was so crazy, outside of Bend Or. 3 Gallons of cooking oil straight into the tank. We were already running well and warm when we put it in and we didn't shut down to feul up when we did make it to a station, of course we only put like 3 gallons of deisel in it then. Donut shops are another good place to get oil. Its usally pretty clean and no animal products! We have a few times just put in svo mixed with the deisel, I wouldn't recommend it all the time, but we have always gotten where we wanted to go.
Oh man, you guys have the sweetest wheels. I plan on doing a bus conversion this year for Burning man but the planning part is all crazy. I have no skills in the drilling, electrical construction part. Heck, don't know how I'm even gonna get the seats out yet. I do know I only want a temp set up (like when I go camping but more comfortable) yet the website I've asked questions on rarely gets any serious answers from the long timers. I'm looking at full-size (35' or 11 windows) gas engine, leaving the windows in, tearing the seats out save for the first row and getting some kind of carpeting down, etc. So far I have plans for a small kitchen (regular camping stove w/ propane), rv mini-fridge, food grade barrel for fresh water for the used sink w/ greywater tank (also a barrel), and folding bed/couch for the bedroom. Not bad but no bathroom! And how the heck do I get one of those in?? Wish me luck!