Errr.....don't think I ever said I was obsessed over mpg ?
My current Scirocco TDI doesn't actually achieve the published figures, but then I never thought it would, and it doesn't worry me one bit, especially as I drive it quite "enthusiastically". The question was more whether the GTD will give me similar economy with 18" alloys that my TDI Rocco does with 18s. If it does, I'll be well happy, as the Rocco gives me a average 45 mpg without having to worry how I drive it.
If the GTD gives me the same economy despite it being more powerful and thus not having to "nanny" it to get a consumption figure that I'd be delighted with, then the GTD will be even more the perfect car for me than I already currently think it is.