Originally Posted by car_fan
I like the high strung nature of the S65, the rawness makes it fun in my book. I hear you re: Displacement/Torque, coming from 3 prior N63's one DINAN flashed (claimed 573 ft/lbs) the luxury of having torque down low is a great thing - but I feel the S65 does very well with 295ft/lbs especially when coupled with DCT.
Given the choice I wonder if anyone here would swap the S65 with an S62 in their in E9x - personally I would roll with the S65
I personally would not do that swap. There is some precedent for running the S62 in the E9x platform though. Turner does it in their Rolex M3s -- http://www.turnermotorsport.com/race-cars.aspx
I owned an E39 M5 for 3 years, and had both my M5 and E90 M3 for a few months.
Fundamentally different engine characteristics, both awesome. I can see having a preference for either.
Gun to my head I'll take the S65 because of the excitement factor. Nothing the S62 delivers can match the thrill of power building to 8400 rpm, IMO.
On a side note, I've never experienced an engine that loved the cold like the S62. Felt closer to 500 hp than 400 in freezing temps and below.
As far as reliability, in my experience both are bulletproof. (My M5 was a 4/03 build.)