You might wanna get some logs done on vcds on that one, does seem strange. My sport mode feels faster than normal, yes sone of its in my head
In my semi-scientific dash from Billy Mill roundabout starting at 25mph at a slip road to a sign I use as a marker, I could pass it at 80mph in my MK5 170TDI PD, 78mph in my 140TDI CR Scirocco, 83mph in the Scirocco 170TDI CR, and 81 mph in my GTD (Sport mode, best attempt). All in bone dry, non-windy conditions, only real variable was the temperature, and the GTD was done at 18C with 1000 miles on the clock mid-October, so not comparing freezing with boiling ambient temp.
For this reason I thought my GTD was only kicking out 160PS and looked into the tuning box options.
I gave Normal a go out of curiosity recently and passed the sign at 85mph twice in 2 attempts, both in the dry at about 8C. Definitely think my Sport is Normal in disguise, except the steering is heavier and more direct and the Soundaktor is louder in Sport mode.