[Buzz]

I guess a good way to look at it is to think of the the thermostat's job as being to limit how COOL the engine runs not to limit how hot it gets. That becomes the function of the radiator and fan(s). The thermostat is there to limit the effectiveness of the cooling system until the engine approaches the upper end of the ideal operating temperature range. If your engine has an overheating problem, no thermostat regardless of how low it's set to open will help. If your rad and fans are inadequate, the temperature will continue to climb as long as the engine is running. If your cooling system is efficient, however, the thermostat will stop it from cooling the engine below that optimum temperature range.