[nachob]

You find all sorts of opinions but for some reason everyone thinks their opinion carries the same weight as the experts. BMW engineers say to break it gradually for 1200 miles then change oil diff and trans. Then work your way up. They built it and engineered it so why not trust them over some nut with a forum account? All the demo units and delivery center cars are broken in by BMW. Period. I have asked the head of M marketing personally because of yahoos say they don't. You also get yahoos that even work as techs at dealerships say drive it like you stole it. First, they are not engineers, secondly if it breaks they get business and third and most important they will say silly things like I drove all my M3s in the past without breaking in and no problems. The problem with that is that many change cars every 3 years or blame something else for the failures. Nikasil engines failed yet some are fine? I wonder how many of them were broken in properly?

Finally and most telling of how non-sensical quoting past experiences with previous engines or motorcycle guys that say during break in you have the most friction so run it hard to seat piston and rings is that your M3 and M4 does not use old school iron cylinder liners but a fairly new liner where material is added directly to the aluminum block through a welding process so past experience with previous BMW motors means very little in that respect. The combination of cylinder wall and rings is different with F80 than previous engines. Not to mention other components like diff and trans that benefit from break-in.

So be smart. If in doubt listen to BMW. They tell you how to break it in. Hope that helps end your dilemma.

As far was warm up drive it mellow to let all the alloys come up to temp and finally don't gun your engine right before turning it off as many do. This spools up the turbos which keep spinning after you shut then engine off. I don't know of the current car continues to push oil through the turbo bearings after shut down so just get into habit of not revving it just before shutting off motor.