Not buying the claim for a 100% to 400% improvement in fuel mileage biodiesel over petroleum diesel. Neat biodiesel (B100) has less energy content than diesel #2. More interesting is the reduced emissions. More here.

I don't know anything about hacking a bus but in 1967 in Alaska during the sesquisentenial, we met a man who had hacked a bus. He had cut the roof off and inserted a riser and then put the roof back on so he could stand up in it. He also gave us some sour dough starter. I got mine form my Dad and he and I have restarted each other's starter ever since. Doesn't taste the same though - been contaminated by too much local flora so it really isn't the same starter. So, nevermind.