There are already many vehicles that will do far over 55mpg on a "fossil fuel" powered engine. Unfortunately, higher mpg = higher carbon emissions. As long as the Govt and Oil industries control environmental regulations, they can easily control maximum mpg by regulating how much emission can come from the engine (and thus, how efficiently the engine can burn gas).

Simple logic, theyre just hoping everybody keeps buying the environmentalism sales tactic so they can continue to force us to buy electric cars or low mpg cars. You are either buying their lithium, or overpaying for their gas...