Reading through all of this, the Chevy Volt's formula of electric car which happens to have a gasoline engine seems like the interim winner. Even the Prius seems to have latched onto that formula. For now, it seems like the ability to supplement the battery range when needed is what we'll have to live with as batteries themselves ramp up their energy density. Matt Farah, not exactly known as an eco-minded individual, is actually excited at the possibility of getting his Volt back. He mentioned once that he'd gone 8 months without putting gas in the darn thing.