Remember that we are driving what is basically a 2 tonne (often more) rectangular brick that makes no attempt at all at being aerodynamic. It's never going to be great on fuel consumption.
I'm in a euro 5, T32, 140 manual 6 speed, remapped to 170. A 50/50 mix of motorway and rural A/B roads. 70mph on the motorway and pretty quick on the A/B when you can (which is often as I'm on the road at 5am), but I get up to speed gently, no real hard acceleration. I'm averaging about 575 miles per 80l tank, but I can get that a lot lower if I drive more aggressively, I just choose not to, unless I'm really in the mood for it.