Tomei Oil Thermostat Killer 4G63 Mitsubishi EVO 4-9
One of the seldom-weak points of 4G63 is rising of oil temperature. It is seen more often in circuit driving. Evo uses thermo switch that will work when the temperature gets around 85?. Yet when the oil temp is low, it will restrict oil flow to the oil cooler and raise the temperature of oil consequently. TOMEI oil thermo killer lets oil to flow into the oil cooler constantly regardless of its temperature. Still, it is easy to put it back to stock thermo switch in winter to prevent over cool.