I managed 52mpg on my 33 mile commute home today. A mixture of back roads, A roads and a short section of busier motorway, where speeds varied between 60 and 70. After only a couple of week owning my 2013 GTI, I can't believe what it is capable of. I am not intending on driving particularly economically, just focusing on reading the road, and the traffic to maintain momentum wherever possible.
The back roads are largely downhill on my way home, although i still I get 38 on the way into work. Averaging around 41/42mpg for the tank so far.