http://www.stewartcomponents.com/htm...hermostats.asp
These are cool. Not sure if they are "necessary" but in concept and design, they are neat. They are certainly a higher quality piece than the stats you get at Auto Zone. I bought a 160 and a 180 from here and have the 160 in. Unless it's hotter than the blazes of hell outside, engine cruises at about 65-70C, which is too cold. Will be switching to the 180.