The bar has been raised: 40 mpg combined is the new 40 mpg highway. While our 2012 list of fuel misers included every car with a highway (or city) rating of 40 mpg or better, this year we required the tougher rating of 40 mpg combined.
http://www.kbb.com/car-reviews-and-news/top-10/40-mpg-cars-2013/?selectedindex=0