On Friday, December 26, 2014 4:00:53 PM UTC-7, Bill T wrote:
The C-182RG I fly is not fuel injected and no good engine temp gauge. So that's what I do for cruise, lean until it stumbles then one rotation rich. Vernier mixture control. Learned that when I first learned to fly in C-150s. Same technique still works.

Adjusting to the break point between rough and smooth gives best power mixture. To get best economy mixture, lean until the engine shakes so bad you can't stand it - then enrich the mixture slowly until you can just barely stand it. Best economy will always be slightly rough.