Forgot to say I also had a 1.1 litre Panda Active that did low 50s mpg (manufacturer figure was about 56 I think) on the identical commute I do in the fiesta, although it was obviously very slow to accelerate (it needed a damn good thrashing but was still economical. I sold that and the D5 diesel volvo to downsize.
maybe ecoboost is good for town but crap on longer runs???
Remember air resistance is lower in town!