Setting the mixture to around 25C ROP is the worst setting for a piston aero-engine
whatever the power setting. It will produce the highest CHT possible for that power.
Given the choice of a 74% power setting with a CHT of X and a 74% power setting with CHT less than X, I choose the latter.
Detonation is not the only thing that is detrimental to engine longevity. So is heat. The manufacturers say so.
