Well, here’s that biodiesel/WVO confusion again. Greasecar specialized in vegetable oil conversions, not biodiesel. Seems like the tradeoff is biodiesel, once made from vegetable oil, is somewhat compatible with some existing diesels, while vegetable oil required quite a bit more up front vehicle conversion costs, but then you don’t need to convert the vegetable oil to biodiesel.
Some folks make biodiesel out of vegetable oil with a process using several dangerous chemicals.