Originally Posted by ozinaldo
Obviously. In fact, this was well known before. When BMW M opted for the N54 for the 1 series M coupe development and not for the N55 both engineers and executives made clear statements about N54 being more suitable for extra power and torque and for further tuning possibilites, there were also rumours that the N54 wouldn't be able to meet forthcoming tighter emissions standarts in various markets. Plus, the two turbo set up of N54 gives less turbo lag. N55 is really an emissions and consumption oriented unit despite similar or identical output.
The rumor is that the next M3 is going to have a modified version of the N55 so it can worst! Also i have had both engines and believe me the N55 has less lag and its faster than the N54 in Stock conditions, not even to mention a 135i N55 DCT with PPK Stage 2 its faster than a M Coupe in straights. I also have had confirmation from different countrys BMW Techs that the N55 is a better engine