Originally Posted by rbaldwin28
The N55 has a Cast Crank Shaft and the N54 has a Forged Crank Shaft. Suggesting to some that when people start finding the power limits of these motors the N54 will be able to handle more. I think the best 335i is the 07-09 with the N54 because now if you buy new you have to get a 335is to get the N54.
As far as I know 2010 was also N54 (I had one), and I heard the rumor that starting 2013 MY 335is comes with N55...