Love this topic.
IMHO I think that most Fiesta owners are too embarrassed to admit that they have chosen a car with lousy MPG performance and exaggerate to hide their embarrassment..
I have had my 1.4 automatic titanium for 4,700 miles from new now...Wifes choice. We are still touring in Europe at speeds not exceeding 50MPG, using feather light touch on accelerator and very little braking, relying on road conditions and use of manual part of gearbox to slow the car down. Tyres are all checked daily and the car only has two people in and very little luggage.
Average speed on tour is 27 MPH and average MPG against petrol purchased is a miserable 37 MPG. Most driving is over 100 mile distances and on smooth, easy roads.
Sorry, but if you want a good MPG car then buy a Volkswagen.
If you want an average about town and country car that is easy to drive and cheap to maintain, buy a Fiesta.
I have come to like most of it but economically, a definite NO.
Swings and roundabouts but definitely lousy MPG.