IDLE fuel/HP requirements

[garfield at pilgrimhouse.com]

I sent this out once before, over a week ago, but saw no responses, and
can't remember if I ever saw it even reflected back, so here goes: once
more, with feeling...

In all the discussion on figuring injector duty cycles/fuel rates, etc.
for WOT, I don't remember anyone ever discussing estimates on IDLE data.

What's a rough ruleOthumb estimate on how much fuel or HP is typical for
idle, assuming just the minimum additional accessory loads of a water
pump, oil pump, fuel pump, alternator. If MAF is usable at this low an
rpm, anybody have some example numbers, from air intake, even. I
understand we're in an area where things could vary widely; I'm just
looking for a rough place to start. Anyone with measured injector signal
timing at idle would be instructive, too.

TIA
Garfield