I have gotten as low as 240 and high as near 500 miles all a matter of driving. If all highway you can crack over the 500 a little. The ecoboost tank is smaller than other mustangs with only 15.5 gallons full capacity
i was getting 19-20mpg in town until I put the FRPP Sport exhaust on.... now I can't get over 17.5-17.8 and I'm trying my best to take it easy but it sounds too good .