Gixxer's Pure Turbo / Active Autowerke e70 X5M on the AWD Dyno at Mpact East 2017 in Pocono, PA 596awhp/612awt on pump gas! (20% AWD driveline loss) Watch out for the flames!
The reason is the special headers used on the S63 engine. They use cross-flow pulses which means all the exhaust pulses line up. I.e. No V8 burble because no collision of air gasses.
None. The N63 and S63 engine are sadly very unreliable. Makes me weep because I've driven both and they are incredible engines if not in for maintenance. x5 35d with M57 engine is the better option won't make quite as much power but enough to satisfy most.
Proper maintenance is the key. Mine had all updates and Service Bulletins from BMW addresses before tuning began. I had “0” issues, no “check engine lights” or anything to go sideways. It was super reliable and could have been daily driven..... but I wanted to keep it super nice, so it only got driven on nice days
