I reset my MFD last july when i bought the car and at the time it showed 32.6mpg and would give 360 miles on refil, now it shows 22.8 and 300 miles to a tank but only does 280 before another refil of v-power is required!
i'm running the equivalent of stage 1 but these big heavy lead boots like to hold the pedals to the floor
I once got 40mpg on a nice relaxing midnight drive to Doncaster at a steady 55 (average speed cams) but i didnt buy a gti to worry about fuel costs!