[bruce.augenstein@comcast.]

Originally Posted by swamp2

Some fair points here foot, right from the database I helped compile. My forgetfulness of these very figures is a bit embarassing. Do look and think a bit deeper though. No one is saying the M3 hands the RS4 a beating. Most reasonable folks know and accept them to be pretty darn close rivals in most areas that matter. However, in thinking this whole loss thing through consider:

1. Ignore the 0-60 mph, 100km/h, you know better. Those times are traction limited and even the power sapping quattro can do as good or better than an equivalent power to weight ratio car.
2. The Audi RS4 weighs more than the M3. There seems to be massive diagreement between US specs and European ones for the RS4 weight and no real quorum anywhere. However, it seems to me the car is very close to 4,000 lbs.
3. The distribution of times and particularly its best times are more indicative of a cars ultimate potential than its average times.
4. In this list, obviously focused around the M3, there are way more M3 data points. If you had an equally large sample, from an equally wide range of sources, I guarantee you would find the the average values for M3 figures that most heavily depend on power to weight like trap speed and 0-100mph/200kph will be better for the M3.
5. Each bearing and gear set in a hub or case provides losses, as does the lubrication process, pure, simple, undeniable. The Quattro has way more of these so it will produce higher losses. The wheel dynos and opening post in this thread demonstrate this common sense/well accepted fact perfectly well.
6. Audi should, eventually, provide a system that mitigates losses better with 100% power transfer to the rear end under normal non traction limited hard acceleration. Then you would only have the weight penalty to deal with.

Swamp, near as I can tell, the RS4 performs about the way it should against the M3 in an acceleration contest, taking into account the weight difference, and the undeniable fact that anybody's awd takes more power to run than a comparable rwd system. You're right that more data points would be better, but frankly, just looking at those numbers (and others that I've seen), the differences both feel about right and come out about right when doing very basic analysis.

As we've discussed previously, a system that can apportion power to 100% anywhere is preferable, but when you look around out there at all those available systems, Quattro comes up with decent marks.

I know you're not taking any particular position, but just thought I'd take a break from my discussion with the so far content-free guy.

Bruce