My 6000 lb Chevy truck gets 13-14 mpg,and my 3100 lb Chevy car gets 25-28mpg.
My parents' 1970 Opel station wagon got 28mpg,it probably weighed less than 3000 lbs.
All this tinkering with fuel systems can squeeze out a few more points of efficiency at ever-increasing costs per percentage pointb but the laws of physics can't be changed by any government .Not even one lead by the Kenyan impostor.
Sir Isaac Newton knows more about gas mileage then the EPA !!!