Dennis Haynes wrote:

<After long runs, I always let engine idle down for minute or two before
turning off.>

Extremely good advice.
From some time spent messing with so-called exotic cars, that's one bit of
knowledge that has stuck with me.
You always let an engine warm-up until the oil temp starts to rise before
putting any load on it and you always allow an engine to run at between idle
and 1500 rpm for several minutes after a good run to ensure proper cool-down.

Sam Bateman
Fork Union, VA
'87 Vanagon GL (too poor to afford any exotics now!)