Originally Posted by
Lead Balloon
If you're interested in maximising the longevity of an engine, it's better to sacrifice some fuel efficiency by going further ROP, or better still to sacrifice a few knots in return for greater efficiency by running LOP.
What evidence do you have that this improves longevity? By how much?
According to one of John Deakin's articles, Lycoming said they have collected data that indicates more problems with engines run LOP.
Deakin's conclusion was that Lycoming didn't know what they were talking about and it was because the pilots weren't doing it right.
But Lycoming are in the best position to collect that data. What evidence is there that they don't understand the data they are collecting? Alternatively, would they really lie?
If Lycoming really wanted to sell more engines or parts they could just reduce the TBO, or require mandatory replacement of certain parts like Rotax with their 5 year rubber & fuel pump replacements.
And I have already given my opinion on the APS attitude that if you DO have problems when following their recommendations it must be the pilot's fault.