Ran my TFSI DSG for the first 5000 miles on 98 Ron (Super Unleaded) then (Feb 08) changed to 95 Ron (Normal Unleaded) as an experiment for 2 months. Please see the thread entitled "DSG TSFi Mpg......." for the ongoing results.
Based on the results to date:
I have seen a drop of approximately 1.5 to 2mpg. Taking into consideration the cold weather we have had and the fact that I have had several occasions in the last few weeks to "really put the car through its paces" whilst demonstrating it to several friends who have taken an interest in purchasing a new car
AND the difference between the cost of Super and Normal unleaded petrol. I am
I "personally" have not had any "noticible" difference in performance which possibly a true Petrol Head would
. All I know is that if I have to deal with the occassional "Sunday Driver" or "Fog Lights on CHAV TWAT" Well............. Jobs a gudun
An additional few points to note in respect of the results
I do not drive like a boy racer
but then again I am not a granny driver
I do not drive many miles per month and the majority can be considered as "Urban" driving only.
My own decision at this time is to stay with unleaded
which, if I do get problems, WILL get sorted under warrenty because (as said in previous responses) this is what the manual (and filler cap label) says I can use