Mr. Gasket High Performance Thermostats eliminate the huge swings in coolant pressure that plague lesser thermostats at high rpm, when coolant temperature and pressure can battle for control of the thermostat and prevent it from opening at the designated temperature. Fully compatible with Chryslers, Dodges, and Plymouths, they open at 160 degrees every time, regardless of engine rpm, and their high-flow design and brass and copper construction eliminate the damaging effects of cycling when youre stuck in stop-and-go traffic.