[NTTY]

Originally Posted by ksoze

Actually, although the engines are different, they are pretty close. $1,700 in Dinan will even get you within 10HP (still not the same car however).

From Motor Trends initial review of both cars:


https://www.motortrend.com/news/2018...-m550i-xdrive/

Yeah, power is not all, and there are plenty of updates in the M5's engine to achieve more power and cope with additional heat and potential (track) use (abuse) of the car.

Motortrend mentioned some but not all of them (I'm thinking of the air intake for instance, and BTW the compression ratio is not the same between the two engines). The document I referenced before is badly documented mixing comparison with the M550i N63TU2 engine and previous S63 engines in the M5 F10 and X5/6M F8x (S63B44T0 and S63B44T2).

To get the complete picture, one would need to read in full N63TU, N63TU2 and all S63 training guides :-)

Cheers