Robert Bonomi wrote:

....
Iowa's _entire_ corn crop, used for fuel, might make a 2-3% reduction in
petroleum fuel usage in Iowa. With a realistic level of diversion to fuel,
you might get a 0.5% reduction _in_Iowa_. On a national basis, probably
an order of magnitude (at least) lower.

It's not a panacea, no...never claimed it to be. It is a positice
impact, however, and has an added benefit of increased markets for ag
products...

There's 200-bu corn raised even here, though. Not that it's
actually that high an average, that's true. There are so many different
"barrels" I wasn't positive which one is the one used in the general
sense. The 31.5/gal factor came from my Perry's Chem E Handbook...