I was reading about the S4 with the twin turbo 2.7L engine and found out some of the A6's came with the same engine. I am a larger guy and figured I might need the roomier A6 but wonder how much do I give up in performance going from the A4 body to the A6 body. I had planned on modding it to Stage I or II level eventually and wanted to hear from A6 owners.

 

The 2.7t in an A6 pretty much makes it a rocket, especially with any mods to up the power. But the heavier A6 will stress the trans more than a lighter car, and, of course, the heavier the car the more mass to accelerate (basic physics - can't get away from it...) Manual 6 speed is less prone to break (and more fun IMHO).

I'm 6' 2" and it fits me great. Most fun car I've ever owned (next to my Maseratis) and I wouldn't give it up for anything. A6 is just a perfect size for a sedan, as far as I'm concerned.
Jim

 

There is not as much a weight difference as you would think -- about 400lbs. I have both a 2003 A4 3.0 MT6 and the A6 below, and they are both comfortable cars. The big difference is when a guy like you pushes his seat back, there won't be much room for rear seat passengers. if that's not an issue, the S4 should be a little quicker. As mentioned, the MT6 is a better choice since you can put in a heavy duty clutch (I had to) and there is nothing you can do to beef up the tip.