** If you switched to multigrade too soon (before oil consumption stabilized) the break-in process stops.**

The last 125 or so engines we have broken in we did so without EVER using mineral oil at all.  The several of the top builders never place mineral oil in the engine AT ALL.   All of these engines were all finished with the breakin procedure in less than 5 hours.  Based on extensive experience and data downloads from a large sample of engines, if it's not fully broken in by 5 hours, something is wrong and needs to be addressed.  HAVING to use mineral oil is an old wives tale--held over from the 1920s.  There are actually reasons NOT to use mineral oil, but they are minor and not worth arguing over.

What is it about AD oil that you think will stop the breakin process?

Walter