Let me bring some real insider news(don't ask me where I got it and who I am but you will see
).
Start 2nd half of next year, N55/N55HP will be replaced by an newer version of N55, power goes up ~10-15% and wil start with F32, F10 LCI and F15 X5(Sorry, no current F30 sedan), then all cars with N series L6 Turbo in the next 2-3 yrs(includes F30 LCI). This will reduce the SKU and hence lower the overall cost.
The all new N series L6 turbo engine under R&D now is coded N58, displacement very likely stays the same but while its N55 predecessor uses a single twin scroll turbocharger, the N58 is going back with twin-turbochargers again however
with one twin scroll turbocharger and the other one is not! Power target is 370-400hp range. It's going to hit the market between 2016-2018(2016 the earliest), which is the perfect timing for all new 5/X3 series, F32 LCI, F15 LCI, etc...
V8 engine will stay pretty much the same, which is the current N63tu, it will replace all N63 next year, though will also get minor tune here and there and goes to 500hp club in the next 3-4 yrs. Currently not sure if displacement will stay the same after 2-3 yrs but as far as technology is not going to be any major changes.
There is also a diesel engine coded N59 under R&D but I am not a fan of diesel so not even want to bother...
