Quote:
Originally Posted by bruce.augenstein@comcast.
Bottom line, I'm not trying to say anything about which car is better, just that based on what I see in this string plus my own experience, Quattro is far from "horrible", and it certainly isn't particularly power hungry.
|
I'm won't comment on the relative losses comparing Quattro vs. BMW except that the 100% rear bias available on the BMW does help substantially. I think the point is that regardless of the design or manufacturer AWD systems produce a significant amount of loss. If you believe the particular dyno numbers in the OP the RS4 losses are 18% vs. 12% for the M3. This difference is consistent with numbers used in simulation (numbers thanks to you, with my tweaks) of 3% for axles and 1% for a diff (12+2x3+1 = 19). No matter how you slice it 6% is a lot and for cars in this power range it is ~ 25 hp. In lb, at 9 lb/hp, this is ~ 225 lb.