Review on The MotoRad 7302-170 Fail-Safe Thermostat: Reliable Temperature Control You Can Trust by Chadwick Webster

I decided to purchase this Failsafe Thermostat because in my experience as a car owner and mechanic, a failsafe mechanism can mean the difference between saving an engine and complete failure. When the thermostat doesn't open, heat builds up pressure. Many automakers use the cheapest parts unless the car is expensive. When the pressure increases due to heat in the cooling system, that pressure has to go somewhere. On older vehicles and high mileage engines, this pressure is sometimes relieved by the cylinder head gasket IF the original thermostat is stuck closed and the radiator cap does not release the pressure above the set limit. Seals age, and when the head-to-block interface is under constant thermal stress as the engine burns fuel and flows through the coolant system, a weak point often develops. In my experience, a failsafe thermostat will stay open as your car cools and save you from blowing up a head gasket or other component in the engine. Think of it as cheap insurance! Highly recommended.