I've just done an experiment. Same route, same-ish conditions, and same speeds and comparing Tesco 99 with a tank of 95. I've easily got 37-40mpg average door to door on a 98 mile journey, mostly M4 and D/C in both West and Easterly directions (so accounting for prevailing wind direction).

Just done the same return trip, 34.5 out and 38.1 home on Tesco 95. Runs just as smoothly, possibly a little down on thrust, but there's more than enough power for that journey / economy driving.

2012 TSI 5k on the clock.

I think the TSI can run on normal unleaded,its the TFSI that's meant to be run on super unleaded.

Yeah got that (I had the TFSI previously

Yeah got that (I had the TFSI previously). Both were remapped, if that makes any difference.

The map on your car was developed for use with high octane fuel

Exactly! Thus my surprise at the economy / general performance on 95 RON.