Originally Posted by Tom C
The M5 is only lighter by 142lbs , whereas the dyno showed 30+whp and 50+wtq advantages. Yes, the DCT is a more efficient set up and quicker. But the AWD on the E63 S also helps it efficiently put power to the ground. We are talking wheel hp where the parasitic loss from the AWD is already being factored in so the E63 S's 540awhp is already being impacted by that. So the AWD and DCT advantages are kind of cancelling each out. Lieberman alludea to the fact that BMW's are more finicky on a dyno. Like I said, the way the M5 is performing is much closer to 540whp than to 500whp.
The AWD improves the ET not the trap. The Benz will have a better 0-60mph and 60' time due to awd.
The DCT contributes to both a faster ET and trap for a given power to weight compared to an inferior transmission. This is best illustrated by comparing a given car available with a DCT and non-DCT transmission i.e. the e92 M3.
The AWD contributes primarily to a lower ET when compared to RWD (assuming street tires) and contributes minimally if at all to a higher trap speed. This is best illustrated by comparing a car available in both rwd and awd, there are quite a few.
"Finicky on a dyno". That's what you say when you don't know much about dyno's and you're suprised by the observed result i.e. have no other explanation.