I think I briefly saw 40mpg one day which was a bit of a shock. I'm amazed that it's even possible to see 50mpg in the GTI regardless of how you drive
I've never even seen 40! I briefly got to 38.9 once, then within 2 mins it was back down to 31

40? The girlfriends Mk5 used to return 23.5mpg with her at the wheel (!) and even my fast (but very slightly smoother) style only produced an average of 28.5mpg! (About the same as I was getting out of my E90 BMW 330i Auto at the time).
If I see 35mpg long term, then I'll be very happy, but given that the boys at EVO are only getting 31.2mpg out of their long term test car - somehow I doubt it!