I think sadly for me since I have to use my car for work and when I'm also travelling 500 miles round trip to see my fiance, I tend just to plod along in it.. I know its got some power and that its fairly quick in standard trim, but I dont need to go revving the nuts off of it to enjoy it
Where I live there's so many narrow roads and bends in the way, its more fun trying to manage to keep the speed as near to and if safe to the roads speed limit rather than seeing how fast you can go from x mph to x mph before braking hard as hell and its not a good thing considering the standard brakes arent great anyways (maybe thats my fault coming from £3500 of AP Racing brakes from my Scoob??

) Those have definitely got to be changed!!
I always reset the trip counter after filling up, noting down the mileage and amount of fuel put in and I just work it out from there. I found my TDI computer to be miles out.. When it started telling me I had averaged 80mpg's I did think something was slightly a bit wrong!!

I have had a GT TDI 130 (about 9 to 10 months I think) and whilst that was an ok drive on a long journey for the econemy (spelling) (at least 50mpg) I couldnt stick with it, it just wasnt my type of car. Mainly due to always having had petrol cars and performance (well mostly) petrol cars at that..
Saying that tho, my GTI does seem to be easy to get 400 miles from a tank without hassles and generally has no problems building speed up rather quickly either..
That said, my lowest MPG since I've owned it is only 35mpg.....
One thing I'd love to do it get it on a set of rollers as I'd like to see what its pushing out in both torque and bhp....