al:

with engine optimized for 87 C thermostat, the 80 C unit would reduce fuel
economy, increase emissions, and limit heat available inside, especially
in bitter cold weather. i think lower temp thermostat might be helpful in
extremely hot weather, especially off road or for really high speed
driving, or to compensate for another problem, but is not necessary for
most applications.

the thermostat on our '84 1.9 l evidently failed open, which was lucky,
because without lowering the exaust pipes on this particular van, it is
impossible to remove the lower thermostat housing. believe me, i've spent
hours jiggling, and it is impossible. the van runs great, but a little
cool in our mild w oregon winters. we more or less have a rule against
driving it in sub-freezing weather anyway, which allows me to leave well
enough alone, and also run 20W50 dino oil year round.

incidently, i had a thermostat fail closed in another car last week, and
it was tedius driving 1/2 mi, letting the engine cool off, then another
1/2 mi, and so on, a few miles across town, with, conveniently, napa the
last stop before home. i think the thermostat gave a little warning the
day before, but it was ambiguous because i had had the coolant drained,
and just refilled the system after several days and therefore wasn't too
surprised by the car running a little hotter than usual, maybe purging
some trapped air in a short drive around the neighborhood. curious as to
whether anyone has had experience with a line of beck arnley thermostats,
which are engineered to fail open.

dan

On Wed, 12 Jan 2005 01:40:38 -0600, Al and Sue Brase <albeeee@MCHSI.COM>
wrote:

>Is there any reason to not run the highest temp one all the time? Is
>that 87� C? I don't think any manufacturer
>recommends changing thermostats between summer and winter.
>Al Brase