
I had a test drive of an standard RS6 Avant yesterday. Looks and feels like a slightly bigger RS4 when you sit in it but start the engine and there the similarity ends! The noise of that V8 is just awesome compared with RS4's V6. It also feels more 'refined' to drive - you definitely feel the rubbish uk roads more in the '4 but the upside is that it feels more engaging to drive.
One of the most noticeable differences for me was the engine characteristics. The '6 is massively torquey right from idle and just blows the '4 away at low revs. It's also far more linear across the rev range - which is actually slightly disappointing. I've got the MTM Stage I on my '4 and you'd definitely describe it as 'brutal'

Does anyone know how the MTM (or similar) Stage I chip changes the RS6 engine?