[thstone]

"So if the low temp thermostat works so well why won't Porsche put it in all their cars?"

There are two reasons why Porsche installs a standard temp thermostat:

(1) Lower Emissions - the quicker that an engine warms up, the lower the emissions.
(2) Longer Oil Change Intervals - a warmer running engine ensures that moisture gets cooked out of the oil even on shorter trips. This allows Porsche to recommend longer oil change intervals and fewer oil changes uses less oil, reduces maintanence costs, and is considered to be "greener" for the environment.

The above statements are generally true for almost all car manufacturers in this day and age.