LOL ^ Si
Not a GTI, but I've got GTI/Ed30 power.
Usual range in winter is around 510 miles. Summer, goes up to 580-600 on mixed easy going driving.
Nurburgring run saw 720 miles to a tank, 59.7 mpg average for that tank.
I was on track at Bedford last week and I averaged between 17-29 mpg between warm/cold laps. Used a smidgen under half a tank for around 34 laps in total.
Sounded alright too, I can't complain on the black pumps