Originally Posted by CanAutM3
It is my understanding that the break-in oils in both the engine and diff are not designed for maximum performance but rather to optimize the break-in.
What do you mean? I am not 100% sure, but I believe they put in the same type of oil... TWS 10W60.
OP, I pushed my RPMs to 7K+ at least a couple of times during the break-in period. I also drove past 140mph during the same period (autobahn is wayyyy too tempting). Changed the oil at about 1900 miles and no issues at all. About 20k miles now and running strong. Was I right or wrong? I don't know, but I do know this: When I brought in the vehicle to the dealership for the oil change, I asked the mech (who happened to be the "M expert") if he thought I would have any issues later. He looked at me, smiled, and said "It's an M3! It's ok!". So I didn't worry about it anymore.