Today I travelled about 400 km to visit another city (including highways and town driving). The trip consumption was 5,5 l/100 km, which gives 18,2 km/l. I find it impressively good for a 184 PS, 320d GT xdrive.
I drove about 60% in comfort mode, 30% in eco pro and 10% in sport. Used autopilot in the higways.
(Sorry for using the MKS system, but that's how it is displayed here...)