For years we've been hearing about the surprising vim and vigor of people who hit age milestones like 4, which once meant the downhill slide had begun. Now 40 is being touted as the new 30. We wondered if this milestone for people was true for mileage per gallon in cars. Is 40 miles per gallon (mpg) the new 30?
Could this be the de facto standard for a new crop of vigorous, green machines that promise to cart our gracefully aging selves around while taking baby sips of fuel or electrons?