I'm looking forward to a track day in May with the M3. Last year I managed to get 26L/100km out of my 135i. I'm hoping to get to 30L/100km in the M3!!! I'd better take a few jerrycans of fuel on the day! However based on the "drive hard to save fuel" principle I may end up at 10L/100km - doubt it though....
2012 BMW F10 520d M-Sport
2010 BMW E70 X5 xdrive40d