Discussion, please!  If derek's right, I would very much like an
explanation for what is extremely counterintuitive.  I can imagine, for
example, that if there's not much oil, then most of it sits in the pan
without circulating through the hotter engine, with the result that the
oil stays cooler.  With more oil, more would circulate, causing the
higher temperature.  In that case it would seem that you might *want*
the hotter oil--that proves it's moving around.  This is pure 
speculation, grabbing at straws....

Will Self
Billings, Montana
'84 Vanagon