Did you ? You explained about how its got base settings to use 95, not why they have decided to do this and not stick with the MK5s 98RON settings . . ?
Are you sure? Being is this thread is now 18 pages long, I certainly CBA to read through all that lot again!

So . . . . basically, the reason the Mk6 (and just like this new TSI, and its 1.8 variants in Audis) can use 95 for maximum fuel economy is simply down to the fact that Audi must have made advances and improvements in the actual design and specification of this new engine. One of the most common ways is to improve the shape and profile of the combustion chamber through CFD - but unless you have a Mk5 and a Mk6 engine stripped down on the bench side by side - you aint gonna see it. More obvious improvements include a much higher fuel rail pressure - the Mk5 had a max of 110 bar, the Mk6 is 150 bar. Fuel injectors have improved too - Mk5 were five hole and Mk6 are six hole. And then there is the 'valvelift' system. Understand now?

However, future developments of this engine, such as an Edition 35, or a Mk3 Audi S3 - when they start ramping up the power, may very well need to 'go back' to using a 98 brew. But for the 'standard' GTI - with its 'ballpark' 200 bhp - the boffins at Audi have achieved the 200 horses from just 95 brew.
Have I missed anything?
