Lean of Peak vs. Rich of Peak Engine Leaning

The Question:
Should I run my aircraft’s piston engine Lean of Peak (LOP)?

My Thoughts:

If you have the equipment, training, and time to do so, as well as your aircraft and engine manufacturers’ approval, certainly.

If you are a new instrument pilot on your first solo flight into the weather (a very heavy workload);
If you have a carbureted engine with a single EGT probe that sometimes seems to work, you think;
If your aircraft POH states specifically “Lean of Peak Operations are not approved;”
If you have only the vaguest of ideas about Lean of Peak and are unaware of the potential hazards for running too lean;
If the terms “detonation” and “pre-ignition” have you wondering which language are they;
If you regularly forget to enrichen the mixture during descent from cruise;
Or if you are taking a very short flight in Southern California or the Northeast Corridor (complicated airspace) during a very busy time and leaning the engine is the least of your concerns;
Then NO. Do NOT run Lean of Peak. Seek guidance from your engine overhaul shop, your local A&P, the rental outfit’s management, and/or your friendly flight instructor.

If your aircraft has an EGT and CHT probe for each cylinder and they work;
If you understand the various EGT and CHT indications and the required pilot actions for each;
If you are familiar with the symptoms, causes, and fixes for pre-ignition and detonation;
If you have had training and remember it during Lean of Peak operations;
If you have aircraft and engine manufacturers’ data in which to calculate fuel flows for flight planning when LOP;
If when flying you have the time, energy, and workload management skills to use your checklist and manage the mixture for the phase of flight;
If you are willing to return to ROP operations when your time, energy, and/or workload increases to the point where managing once less thing is helpful;
And it is not a sin against your piloting prowess to use ROP as needed;
Then YES. Run Lean of Peak when your equipment allows and Rich of Peak when it does not. Still seek guidance from your engine overhaul shop, your local A&P, the rental outfit’s management, and/or your friendly flight instructor.

I’m a convert from never running Lean of Peak to running it in aircraft with equipment, manufacturer approval, and my workload inflight allows. If time, the aircraft, the POH, or my workload does not, I run Rich of Peak.

When it comes to a coin toss, remember the words of one mechanic from one of the top engine overhaul shops in the country: “We love Lean of Peak; it’s GREAT for business!”

The bottom line:
If you’re trying to make TBO, both Lycoming and Continental Technical Reps state:
“The Number One Rule to Making TBO is Fly Frequently*.”

* Frequently = 30 hours per month minimum. Check your engine’s warranty for the pro-rate.