Two years ago, you bought a 172M with a 180 HP conversion a bit past TBO. After 100 hours you decided to overhaul, and added an engine monitor. That revealed consistently high CHTs, often hitting 430°F in the climb. Today you’re at Hot Springs, SD, with the family. It’s 85°F with density altitude near 6000′. You know that if you lean for best power the engine will get super hot. Maybe that’s fine for a short time. Or maybe keeping things cool matters more, and a full rich takeoff is safer as long as performance is adequate. Or is there a middle ground? If you wait for cooler weather, it’ll be awhile.