The Facts !

[sharplab]

This is the proper way. Lean mixture any time under 75% power or over 3000msl. Continue to lean until you are at cruise flight level and leave the mixture there. This will keep your engine warmer for your descents. If you engine is too lean then it will let you know. Being a little lean of peak egt is fine. Also for your descent set prop and power to 20/20. This prop setting will help keep a load on the engine thus keep it warm. After descent then 20/23 is fine and leave the prop there until short final. Vref usually works at around 14-18 inches man pressure. Remember after flying at 10,000 feet the fuel in your tanks has cooled and richening the mixture could have serious shock cooling effects. Hope this helps.

Stephen C. Sharp
Comm. Pilot