There may be no greater debate amongst pilots than the “rich of peak” or “lean of peak” (ROP vs. LOP) exhaust gas temperature method of leaning the aircraft engine. //

So that leaves us with the question; is it better to operate rich of peak or lean of peak?

Some engines achieve maximum economy range on the leaner fuel side of peak exhaust gas temperatures (EGT) and maximum power on the rich side of peak EGT. Some achieve both on the rich side of peak EGT. The ultimate answer comes from your engine manufacturer’s engine operator’s manual (EOM).