My last 400 odd miles have all been city driving and that tank avaeraged 44.8mpg.
To get it over 60mpg is a real effort, and considering their marketing puts the combined figure at 65mpg I do have to wonder how they get away with it.
I agree it could do with a 6th gear, the car cruises really nicely at 90mph and it would be nice if the revs were 1800rpm or there abouts.
I don't think the bigger wheels make any difference though, I have changed 16" alloys on our 320d touring and on the 2.5tdi avant over to 18" ones and it didn't effect it at all, the circumferance shouldn't change.