I have just filled mine up after 714 miles with 55.76ltr and I make my consumption to be 58.5mpg, the car though tells me it did 63.4mpg
I have the F30 Sport with 5900 on the clock and on this tank I have been driving like a Nanna mainly in eco pro mode with a mixture of motorway, country and city driving. I also have had the aircon permanently on.
Since I have had the car I have averaged 55.5mpg with the worst tank being 52.6 and the best being 59.2mpg. I'm well happy with that (I should say my boss is) as my previous car only averaged 42.5mpg.