Here's a question for all you Audi aficionados: How is it that the automatic transmission version of the S4 (B6, 4.2 V8) gets 23 mpg while the 6 speed manual gets 21 mpg (highway). I can maybe see how the automatic could possibly get better mileage in the city, but once you hit the highway I would think the best the automatic could do is get the same mpg as the manual? If indeed it is true, would this imply the automatic somehow is more efficient in transferring power to the wheels? And if this is true, is the automatic faster?

Thanks,
Doug