I have a 08 330d auto, i have had it two weeks just over, and i think its bad of fuel. but its getting better, i think its my driving style as i have never owned an auto. I measured it tank to tank it managed 31mpg and on the i drive did 30mpg, probably 50/50 town and dual carriageway driving.
I have got low coolant temp also, 79c is about all it manages no matter how fast or slow i drive, so its booked in for AUC to sort my low coolant temp. Also noticed mine after a 20-30 mile drive pulling up to a stop it misfires slightly and the rev counter bounces about abit. Hopefully everything is linked and bmw find a fault which helps my mpg