Just wait 'till the state gets involved…
On the one hand, vegetable oil isn’t considered a motor vehicle fuel in its raw state, and if you’d have to have special EPA dispensation as a “refiner” or fuel processor…
OTOH, I wonder if people go this way, they’d be sued for not paying motor fuel taxes. It’s all nuts, really.
And if you don’t think this hasn’t happened…
http://www.herald-review.com/articles/2007/03/01/news/local_news/1021491.txt