Originally Posted by Spazdoc
What I am getting at is one of my buddies has the 2006 328 (325?) and says the engine is the same as the 330 and 335 except different programming. I do not have enough info to tell him that is waaaay off.
He is wrong. There are enough differences that they are "different" engines; the main, and most obvious one, being that the 335i block is *all aluminum* whereas the 325/328/330 block is aluminum/magnesium. When something is made out of a different substance than something else, most people classify it as "not the same".
That goes without mentioning the iron lined cylinders, or the fact that the N52 has valvetronic, and the N54 is direct injection.
A very simple way to put it is: if you added two turbo's and the appropriate ECU to a 328/330i would it give you a 335i engine? The answer is no.