My car runs on special diesel. It's a bit more refined. I think the name is petrol or something.
Anyway I got 525 miles out my tank from full to empty. There was nothing left in the tank as I pulled into the station. During my journey I averaged 65 ish with one blast up to 135 k
mph 
I know we have a bit of rivalry between diesel and petrol but my car is putting out 270 bhp and 300 lbs of torque. I'm getting maybe 70% of the mpg that a 170 bhp diesel gets. The diesel is putting out about 65% of the power of my car? When looked at that way I'd say the GTI is still a pretty good car for the performance.
And if you want to argue with that go look at a Focus RS owner's mpg claims... yet the GTI can match that thing for pace.