the problem is the whole measuring system is f*cked in europe- it's simuated on a rolling road. these conditions favour hybrid and turbocharged engines which, when driven in the real world will never EVER get anywhere near their claimed totals
as a rough guide: my A3 1.6 MPI and my current 2.0T have EXACTLY the same official mpg figures, but despite the fact i'm older, wiser, and trying to drive more economically the best i've ever gotten from the same size tank on the same V-Power petrol is 15% less than in the 1.6 (PB of 440mi plays PB of 380mi).
turbo petrols are not as economical as their purported to be - i think that's one of the reasons why they're not popular in the US where real world driving is used for the official mpg figures and then there's no appreciable difference between a larger NA engine and a smaller FI engine - and then you factor in that there's more to go wrong. our dump valves for example.
don't get me wrong, i think the 2.0T is a VERY good engine, probably one of the best i've ever driven (and i've been fortunate to drive some very nice metal in my few short years) but it doesn't answer all the questions. i still only average 29mpg or so in mixed driving conditions and tbh that's not great for a 2.0 petrol. i know of VR6 owners who do better.
as a comparison, i remember Clarkson reviewed the 2.0 FSI non-turbo in the A3 when it was first released and mentioned (probably with a hint of hyperbole attached) that he was driving it around in 4th gear because it was so refined he was forgetting he wasn't in 6th and he was still getting 34mpg. i'm sure many of us would consider chopping an arm off to get 34mpg from our cars in a steady 4th gear cruise.
i think the upcoming VAG 2.0 twin turbo soot chucker might be my next engine of choice (whenever they pull their finger out and release it).