Car and Driver tests an S6 and an RS5.

An Audi S6, which has 420hp, weighs 4255, has a 7 speed DCT tranny – does 1/4 mile in 12.1 secs. 0-60 in 3.7 secs.

And here’s an Audi RS5. With 450hp, (+30hp) and more torque - weighs in at 4040 (that’s 200lbs less! ), same (or similar) 7 speed DCT tranny - but only manages a 1/4 mile time of 12.8. 0-60 of 4.4 secs.

I would imagine if the final drive ratio was dramatically different, so I checked that out and...

FINAL-DRIVE RATIO 4 38:1 for the RS5

For the S6 is 4.093

Again, the RS5 should be faster. Yet...?

What gives?

MY 9 year old RS6 is faster than the RS5 – but weighs more and has an old-fangled slushbox (but same hp.)

Yeah, I know there are differences in asphalt, altitude, temperature, but really...this just doesn't fiture.