oil cooler valve in the oil filter housing stock opens at 215f DEG or 100c this low temp opens at 75c or 168 f Part Number: 15999 AM001 found on mitsubishi EVO 8, 9, X The HKS Low Temp Oil cooler thermostat works with the factory Mitsubishi EVO 8, 9 and X.The 75 Degree Celsius Thermostat will open several degrees sooner compared to the OEM unit, which will help reduce oil temperatures and help pro-long the l ife of the oil, and slow down thermal breakdown. http://www.part-box.com/images/15999-AM001.jpg http://www.maperformance.com/images/magictoolbox_cache/8a5b5c23bc6b1e9cbba52829116c6900/2/0/20010/thumb600x308/570801723/S_3594.jpg