LOP operation is irrelevant to the question posed by Lagentum, the thread starter.
He was asking about POH fuel burn for a
Piper Warrior. It is impossible to lean a carburated Lycoming 4 cylinder engine to LOP and still have it run smoothly. It will start to run rough and otherwise indicate its unhappiness well before you are truely lean of peak because the mixture distribution varies so much between cylinders.
Plus to do LOP operation without hurting your engine you need an engine analyzer which gives continuous readings of the EGT and CHT of each cylinder.
If anyone can find even one example of a VFR Warrior available for rent with an engine analyzer, I will eat my copy of Kaz Thomas's outstanding book "Fly the Engine"
