Seems to be quite a variation lately, and it's almost certainly due to ambients (Edit: Monkeyhanger got in there before me). I use mine a lot in town in the mornings to drop off the mrs so my long term isn't great, but did 55 miles of b road and some a road driving last night for the hell of it and achieved 49.2 which seems ok, although the car has only done 450 miles so i'm yet to drive it enthusiastically - it seems thirsty when you go for the throttle.
As soon as there is talk of a DPF delete I shall be partaking in that. I am intrigued by the long term tuning box findings tbh, as the subsequent hotter engine temps seem to defer the DPF regens well enough which is ultimately what's raping us all of MPG.
I'll see what figures she throws up on the drive back to Peterborough tomorrow as my 270K 306 happily achieved 50 on that run with past their use-by date injectors. My colleague at work is achieving 57 on his 36mile round trip work run with his Mk6 GTD (30k on the clock) with a mix of roads and spirited/cruise/overtakes so i'm feeling a little cheated atm. Hopefully it will settle in as the miles increase a bit.
