It's not greener, same crap as Lithium batteries, the champagne swillers in the home counties congratulate themselves on being greener having simply moved the issue elsewhere. Look up the production of ethanol around the world for this stuff. It's tearing up important ecosystems, taking food out of supply chains meant to feed people, nothing green about it at all.

And as you rightly point out the drop in MPG is another kick in the balls, pay the same for a worse product.