Big John wrote
Probably one rational behind keeping engine warm is that if you go to
idle and glide a long time the engine will cool down. You then slap on
full power and the cylinders are hit with a high temperature all of a
sudden.

That's probably the best rationale I've ever heard for 1500 RPM and
one notch of flaps. We all worry about shock cooling, but letting the
engine cool off and then pouring on the coals is a recipe for shock
heating. I might rethink the way I do this...

Of course idle engine will not duplicate aircraft performance with
dead engine.

No it won't. It's also a great recipe for icing up the carb. For
both those reasons, I usually pull the mixture to idle. That way you
get a true windmilling engine, and since no fuel is evaporating in the
carb there's no risk of ice.

1500 RPM is still very low power, and the chance for carb ice is still
there. Not sure whether I'd rather worry about shock heating the
cylinders or icing up the carb.

So, youse kind of pays ur money and takes ur chances )

Yup.

Michael