ok this is what i read on icbmotorsport.com.........."This thermostat has the operating temperature set lower than normal. It prevents engine power loss by minimizing rapid water-temperature rises under harsh conditions such as during circuit driving. The use of a flow-control-type valve prevents hunting, thereby achieving rapid stabilization of the water temperature (the engine warms up within a short period). Operating temperature: 68 degrees (STD.: 76~80 degrees) Full-throttle acceleration temperature: 81 degrees (STD.: 90 degrees)"..."Activates cooling fan at 80 degrees instead of the stock 93 degrees. Requires use of Mugen low-temp thermostat."