I had a big argument with some guys on another forum about the usefullness of a nismo thermostat. I thought they allowed cooler running of the car. It was explained to me that the nismo thermostat in no way makes your car run cooler (which seems to be the common thought here). Doesnt matter that the thermostat opens sooner because once it is open, it is open, and the temperature of the entire system will quickly be the same as with a stock thermostat.