"Roger Long" wrote
I had an idea today which worked well and I wonder if anyone sees a
downside. I always operate our 172 N on the ground leaned to the max.
Instead of using the brakes this morning, I just leaned some more until the
engine sagged and controlled my speed that way. Turning the vernier knob
didn't seem much more work than pushing the throttle in and out. Running
super lean like that must be good for the plugs.

There is no downside whatsoever to your idea. You can't possibly hurt
your engine by overleaning at these power settings.

However, if you're running so lean that you're reducing power by
leaning, you have no need to maintain 1000 RPM. When you're running
that lean, you can run the RPM as low as you like and you won't foul
plugs.

Michael