How you run your engine depends on what engine you have, 470/520/550. My 200B has the IO-550F and I generally do short trips of 30 minutes to 1.5 hours at 4500′- 5500′. I’m not concerned about the fuel burn as I like the speed. I will run it at 23″@ 2400 186kts gps ( no wind ) and fuel burn around 19gph. Flew from my home airport CA32 ( San Joaquin,Ca ) to Columbia,Ca on Saturday at 4500′ 24″@ 2500 208kts gps (a nice tailwind) burning 20-21gph. The return trip later that day at 5500′ 23″@ 2450 was 168kts 19gph (damn headwinds).On a cold day 500agl everything firewalled it will indicate 220mph and around 25gph. When I do fly at higher altitudes I will lean until it runs rough then richen the mixture so it runs smoother
