Well I acheved 42 mpg between Edinburgh and Perth sat at on the motorway and then 39 mpg between Perth and Aviemore on single carriageway (overtaking took its toll on economy) On the way down i got a lovely northerly wind blowing me back to Edinburgh so I got 44mpg, my best long run average
I didnt use the cruise control but noticed while experimenting that if I activated the cruise the current mpg figure would drop instantly by 3mpg ish
Its a shame, I wont be using that nearly so often now!