There is no 08 model in the US. Ours starts with 09. The engines, turbos, and for the most part, trans are all the same. The newer ones just use more of the reserve capacity that the older ones left on the table for aftermarket tuners. Word on the street is that the 2014 does actually have larger turbos. We shall see.
'17 F80 Tanzanite/SS DCT ZEC/ZCP
'14 991 GT3, Sapphire Blue / Black, 11.30 @ 124
'07 997TT 6MT, Arctic Silver/Sea Blue: FBO E85, stock turbos: 5.9 60-130 (now with 656 whp, 700 wtq)