Radiator Cap Selection

It has become popular to install high pressure radiator caps in an attempt to lower cooling system temps. While some makes and models come from the factory with and are designed for high pressure caps, raising your radiator cap's pressure above factory specs increases your cooling system's maximum operating pressure above design parameters. While raising your cooling system's maximum operating pressure does raise your cooling system's boiling point and therefore helps to avoid boil-over, it does not lower your operating temperature prior to boil-over, and simply allows your engine to continue to operate at temperatures higher than it is engineered for. Water boils at 212 degrees, and for each pound you raise the system pressure it raises the boiling point 3 degrees - Example: The 1.1 bar (16 pound) cap will have a boiling point of 260 degrees. Operating your engine at higher than acceptable temperatures can destroy your engine. We wish to point out some considerations that should be taken into account before an individual chooses this approach.

There are several possible reasons that you might be experiencing higher than normal cooling system temperatures:

Raising your cars cooling system's operating pressure increases the stress on all the other components of your cooling system. Before increasing your cooling system pressure by replacing your radiator cap with a higher rated radiator cap, check to make sure your entire cooling system is in excellent condition and all of the components are capable of handling these higher pressures. These may components include, but are not limited to:

Increasing your cooling system pressure by installing a radiator cap that has a pressure rating higher than factory specs increases stress on the entire system. Although some race cars use high pressure caps, their cooling systems are built to handle these higher pressures (All-Aluminum brazed and welded radiators, steel braided hoses, no heater core, high performance water pump, high performance gaskets, etc). We offer high pressure caps because some cars are designed with high pressure cooling systems. We recommend that you only use a cap with the pressure rating that your car was designed for.