Think about this, my 99 vette (with a vette motor BTW lol) got 31+ almost 32mpg going 70 on the interstate with the ac on. It was 355hp and 6 speed. Why can't they make a 6 cyl or 4cyl car get 50mpg?
Ever notice that the cars that do get above 30 are so ugly nobody wants one. All the hybrids are stupid looking. Make a spoty looking car that gets really good gas miledge and maybe they will sell. I think the car makers make 'em ugly on purpose so they can say nobody wants to buy 'em.