The engineer reported that, although the aircraft had been using oil at a higher rate than previously, the compression testing performed at the last 100-hourly inspection indicated that compression was within tolerances.
The engineer had advised company pilots that, rather than flying at higher altitudes, with higher engine revolutions per minute (RPM) settings and a MP of about 21 inches Hg, it was more desirable to remain at a lower altitude where 23 inches Hg could be achieved.
Oil consumption going up, directed to fly power settings that would produce slightly higher than normal peak pressures, and most probably a lifetime of running at slightly ROP settings creating maximum force on... the.... Conrod! C'mon ATSB isn't anyone in there curious? We've been building these engines for over 50 years really shouldn't be breaking conrods anymore. Unless for some reason these engines are actually very strong but are getting unknowingly abused...
Is there evidence that supports the implied assertion in this report that low rpm / high mp will reduce oil consumption versus high rpm / low mp?