The next move is to terminate the corn derived ethanol being added to gasoline. That will increase the MPG for cars based upon gasoline being more efficient than ethanol. My own proof is that before ethanol, my 5-speed Geo storm got 23 mpg commuting around DC and after ethanol it got 18-19 mpg over the same route. On long trips I was getting 40 mpg before and 32-33 mpg afterward.