46-48 MPG at 70 MPH on flat ground. 2013 Ford Fiesta SE sedan 1.6L manual. Non-Eco tires at 44psi, no other mods. 2 people and about 150 lbs of cargo.
Averaged 50.2 mpg (indicated) on my trip from Vancouver WA to Renton WA (one way) over Christmas break. I was very happy to break 50 mpg for the first time. I was driving at 65 mph when I didn't have a semi to tail, then tailing semis at a 2.5-3.0 second following distance going 65-70 mph when I could. My display reads about one MPG optimistic, so I probably got 49 MPG in reality. Hit traffic on the way back home and finished out the tank with 47 MPG indicated, forgot to check actual mileage when I filled it up
I typically get 40-42 MPG around town (country roads plus some city driving). If I drive it like a "normal" driver it gets 35 mpg around town, or 30 if I use the AC and drive it "normal"