Just to get my fuelly sig in the thread - 2007 330d auto - first couple of tanks were 37ish mpg, then it went into the dealer to have its wiper sorted out with the OBC showing 37mpg, and came out showing 32...
I think they must have left it running with the aircon going full whack for an hour while they looked at it... Twunts.
Hopefully back up to something a bit more sensible when I next fill up
Edit: This is a mostly a 20 mile trip each way to work, 5 miles across town then 15 on an empty motorway at 70mph. Maybe once a week to the shops.