Originally Posted by 1SerieStud
I call BS. Based on what map/tune is used, there could be more or less power to play with. My last experimental car was a 2010 Mazdaspeed3; my buddy had an AP on his 2009 speed3 and that thing was a rocket. The "greater" power gains you see on this engine are due to 2 extra cylinders and larger displacement, as well as 2 turbo's on an n54. Subaru's, Mazdaspeed's, and Evo's are all turbocharged 4-bangers.
The more power is pretty much given for the BMW but attaining it is a different story, the BMW ECU is a much hard safer to crack...