Are you going to be modifying at all, or just working on the nut behind the wheel?
In a fuel efficiency competition last year, the Mustang ran 33.6 mpg (when I was averaging ~30-32 on a tank) and
Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Profile: SecondWind 's
CR-Z doesn't have fuel use averages for then, but he definitely wasn't a slouch, and tipped past 40.
http://ecomodder.com/forum/showthrea...ved-23055.html
This was the final performance, I led by % but they got me by straight MPG.
http://ecomodder.com/forum/showthrea...tml#post335667