Quote Originally Posted by GYSOT1 View Post
This car is all uncharted territory for me. He has the twin turbo 4 in it. I've been seeing all those 'N' numbers being thrown around. What do they mean and how do I find out which one we have?
BMW likes to label their engines just like other manufacturers, And the N52 is the naturally aspirated inline 6 in most BMWs from about 2007/8 to 2013/4. It's in everything from an X5 to a Z4. Turbo variants of it are N54/55.

The 4cyl is the N20. There's other variants, but that's the most common one... Also, despite their "TwinPowerTurbo" label, there's only one turbo on those.