Originally Posted by nick325xit 5spd

In my experience, *very* few people understand the different between Genuine, OE, and OEM.

Here are the definitions that I use:

Genuine: Anything that BMW sells over the parts counter. This may include things like "Genuine BMW Victor Reinz," which is insulting. That said, I use enough genuine parts that my parts guys recognize my voice on the phone.

OE: The actual supplier of the Genuine part. (I will include a previous supplier of the Genuine part in this category.)

OEM: A manufacturer that sells anything at all to BMW, no matter how unrelated to the replacement part being sold aftermarket.

I usually buy either Genuine or OE, unless I have a specific reason not to. Unfortunately, BMW Genuine parts quality has radically declined, so I have more frequent reasons to go aftermarket.

Edit: I will note that there's some grey area here, in my opinion. For example, I don't care whether or not BMW sells Victor Reinz as Genuine or not. It's aftermarket trash to me. Whenever I get a VR part over the counter at BMW, I refuse it.