I just got a new REPLACEMENT engine on my 2009 Clubman S. Any recommendations on how to drive it to break it in? I heard it is good to drive the car hard? Any thoughts? Thanx

 

Well, that's a question that is actually the topic of a current thread in the R58 Coupe sub-forum... There doesn't seem to be any really defining answer, however...

The most consistent recommendation I've seen in that and similar threads is to make a conscious effort to vary the engine RPM through something like the first 1-1.5k miles; don't just drive at one engine speed.

Now, how much one should vary the engine RPM seems to be the point at which the opinions diverge... Some say to keep it moderate (no more than 4-5,000 RPM); others say to redline it occasionally. I guess how you handle the latter is entirely up to you... Personally, I would keep it moderate; but that's just me. Wait until just after the so-called 'break-in' period to start really pushing the engine. I have nothing on which to base that opinion except the belief that putting too much stress (either mechanical or thermal) on an engine too soon after manufacture (i.e., when fit is tightest) is probably not doing it any favors... But I also have no evidence to dispute the claim that redlining a modern engine during the so-called 'break-in' period will not harm it in any way...