Apparently scientists (and some of our readers, surely) have known that we can grow oil for years, and not in the grow-corn-make-oil kind of way.
The Brazilian Copaifera langsdorfii can be tapped (ala maple syrup) for a natural diesel fuel that requires only simple filtering before being poured into a truck. (This picture is of the tree’s cells.) The catch? The diesel only has a shelf-life of about 3 months.