Another thing about the oil level that I haven't seen mentioned is the load
on the crankshaft if it is actually hitting the oil in the sump.  Anybody
notice less power or lower fuel mileage on the full or overfull condition?
I doubt the power loss would be noticeable, but maybe.  I know soem race
engines have precise gadgets in them that are like stationary fins that
"scrape" (don't actually touch the crankshaft) the oil off the crankshaft.
Is that  a windage tray?  I can't remember the name right now.  Even some
street rodders use those.  A friend with a souped up Corrado is getting a
new engine because his hit the crank, got chewed into pieces, clogged the
oil pick up, and then...

Edward