Currently averaging 53-55mpg on an auto ED with 7k on the clock. Not getting more than 600 miles per tank (brim to brim) and thats pushing the fuel warning light down to last 10 miles. I think Signpost's figures will be hard to beat.
Its a shame the fuel tank size is 5 litres short of my old E90 ED, as over 2 years of ownership my overall average MPG was 57 and achieved a personal best of 885 miles from a full tank.
Reducing the F30 fuel tank size (weight reduction) must be to compensate for the overall larger car in comparison to the E90.
Current weather and the car being an auto seems to be the culprit here. Keen to see whats it like when the weather improves.