To assist the proper functioning of a high-performance cooling system, these Milodon thermostats are designed to warm an engine to a suitable operating temperature in order to avoid the engine running so hot that it loses power. A balanced sleeve design enables the thermostats to equal the pressure exerted on them, which allows operation to be regulated solely by coolant temperature. They are recommended for use with a high-volume water pump (with other thermostats, a high-volume water pump's increased flow can actually try to keep the thermostat closed).