That is impressive, modern petrol engines, on a good run, are quiet frugal compared to 10 years ago or so.
I did a round trip down to Birmingham on Friday in my M140i approximately 230 miles, and returned 42 mpg.
Not bad for 6 pots, 3 litres, turbo and 340 BHP plus mine isn't the 8 speed auto with a high top gear.
Admittedly compared to a diesel on more urban driving they can't compare but I really can't see me going back to a diesel daily drive.
Petrol is cheaper than diesel too, and non of the pee injection stuff and particulate filters to worry about...at the moment anyway.