So I bought my 2013 Fusion on 1/14/2015 and I've already put over 3000 miles on it so I thought I'd share some MPG numbers.
It's rated at 22 city/33 highway (FWD) I've been averaging 25 MPG in-town (Pensacola)
Went on a 560 mile trip, cruising @ 68 MPH with no air conditioning I got 33.5.
On the return trip, I cruised between 70-74 mph, air conditioning on, had some additional weight in the car in the form of flatpacked furniture. got 31.7 MPG.
Overall I'm pleased, if a little surprised I wasn't able to best the highway rating better because I have with every previous car I've owned. I guess Ford is really pushing their MPG limits with the EPA for the whole Ecoboost marketing scheme. Can't help but think that my Grand Marquis was pretty fantastic for getting 27-28 MPG in the same conditions when its engine is over twice the size (but less powerful) and the vehicle itself weighs a good 600 lbs more. I guess that's the wonders of an engine hardly having to work at all.