Originally Posted by Roelof

I havn't seen a real test by running an engine on ceramics and by replacing the bearings running that same engine on steel bearings. Only then you can determ the difference.
Believe me with all I have seen on tolerances and fooling customers by giving them different timings and/or other piston material it is hard to say that 2 engines -one ceramics and one steel- are exactly the same to give a reliable test.