Sid,
It was made known to me long ago that running your oil temperature lower than
212-215 degrees F precludes the natural elimination of condensation and
hydrocarbons from your oil thereby shortening your oil's service life and
actually HARMING your engine by retaining fluid contaminants in the oil.
The closer you can keep it to that 215 degree mark the better, but lower than
that is just as bad for your engine, ...in my humble opinion. I was also
informed that organic based motor oils (standard motor oils) are able to
withstand temperatures far greater than 250 before they start to degrade. The
number provided to me was almost 400 degrees F before degradation and coking
begin to take place.
Mike Ladigo