TDI no contest. Living in Europe 0.7 seconds slower to 60 is insignificant compared to an extra 12mpg. Plus all that extra torque!
As mentioned, at idle, that tdi sounds like an americna v8
I voted TDI, theres nothing better than driving into narrow garages, and hearing the diesel roar!
I understand OP is comparing engine noises, but for all of you, comparing a s6 to an a6 is a little apples to oranges, no? Does the s6 not have a tuned exhaust to make it sound sporty?
Does the new BiTDi need the add blue?
Second, the supersprint exhaust, the video mentions reprogramming the dpf, have they found a way to remove it completely, and program the ecu?
For the type of driving I do 95% of the time? TDI.
It'd be hugely rapid and likely deliver high 20's on the city cycle. In a car like the A6, that's fantastic--and much better to live with in the real world than the S6, which would likely return 16-18 I'd think (for comparison, I barely get more than 22mpg in my GTI on my daily commute, which averages 18-19mph).
However, the S6 is huge value against cars like the Merc and M5. Honestly, I couldn't see myself stretching to buy an M5 over the S6.