Having gone from 2l A3 TDi (184) quattro (and the 3l Touareg v6 245hp diesel we still have) to S5, you have to drive them differently. Found this out when testing an RS5 and S4 some 2 years back. Thought they were OK, but nothing special, so discounted them. Whilst the low-down grunt of a diesel is appealing, you need to rev the petrol engines more before they do their stuff. It is something that as a diesel driver, you have to recondition yourself to doing....I did sort out a test drive in the new S6 - Nice but not enough torque after the diesel.