Hitting 52.5 mpg won't require major tech advancement

By 2025, US automakers will have to have an average fleet fuel economy of 52.5 miles per gallon. That standard is 27.3 mpg today, so it sounds like a great, big, scary leap. But not really, say vehicle technology experts. In fact, there's enough room for improvement in things like auto-body design, that we can meet the new goal without needing any major technological breakthroughs.