Originally Posted by epiphone3
which engine is the N53 again? I know the N52 is valvetronic and naturally aspirated. N54 is the engine in the 335i. What is N53?
N53 is the direct injected (HPI in BMW parlance) natuarlly aspirated I6. It starts shipping right about now I believe (March model changed) in the E93 and E93 330i, but only in countries with clean enough fuel (i.e not North America). In its first iteration it makes the same power as the highest output N52 (272hp), but with much greater fuel economy (I think 15% or so).