Purpose of the Thermostat...
Thermostats have a couple of purposes..
First off it keeps the engine at a consistent temperature for even performance.. Since the car is expected to run at a certain temperature the engineers can then plan on fuel delivery, timing and other things once they know what the consistent temperature of the engine will be. This consitent temperature determines all sorts of things including the thickness of cylinder walls, intake and exhaust ports, all of that stuff. With consistent temperature you can build a more precise engine because the expansion of the metal is controlled, wherease free air engines are not controlled and must be engineered with loser tolerances to take into account more expansion.
The second aspect is sludge build up in an engine. If the engine never reaches proper running temperature the oil will build up deposits in the block, thus clogging the filter sooner, leaving sludge down in the block, actually causing the engine to wear out pre-maturely... As a former marine mechanic, Mercury, Johnson, Evinrude, OMC and Chris Craft I can personally tell you there is nothing like a Chris Craft engine for oil sludge in the block. The boat uses lake water directly and here in Colorado, Grand Lake, never sees the high side of 55 degrees F which means the engine never runs over about 120 degrees and the oil just deposits itself in the lifter gallery, etc... Needless to say the first thing that happens on a rebuild around these areas is boiling the block..
Water Wetter is a very good product. In real racing you are not allowed to use Anti-Freeze as when an accident happens or a hose goes you leave the water/antifreeze on the road and it's a hazard to all those driving around you. Water Wetter doesn't provide this slick mess on the road and it is allowed by NASA and SCCA for all of their events. It really does work..