Toobuilder
Well Known Member
...But what I do get with that loss of speed, is 5% MORE engine tach hours because I am in the air longer.
That is 5% more of more wear and tear on the engine. If one gets 2000 hours on an engine, then running LOP will meant that you get there 100 hours sooner then if you were running at best power...!
Do they have mandatory TBO limits up in the GWN? Because if they don't then your example has a significant flaw... There is very little wear taking place in an engine operated in thermally stable cruise condition. Compared to throttle (thermal) transients, and engine starts, cruise operation is as close to eternal life as a piston engine gets. Start any Lycoming, run it at maximum continouus power while feeding it clean oil and ample cooling air, and it will likely run past published TBO several times over.