Nismo Racing Radiator Cap maintains a higher internal pressure for the cooling system than the standard cap (Valve opening pressure : 1.3kg/cm2). It prevents the coolant from boiling and vaporizing easily (the boiling point is approximatery 6C higher than the standard cap's 0.9kg/cm2 threshold) and improves cooling efficiency.

Because the Nismo Racing Radiator Cap keeps pressure in the cooling system at a high level, be sure to inspect the radiator and hoses before installation to ensure that there is no damage or leaks. Older cars are particular prone to problems due to deterioration of parts; even if there was no problem when used with low cooling system pressure, leaks may occur under higher pressure.

There are two common different types of caps, some vehicles may have either or, aftermarket radiators may have a different one from the compatibility notes. Please check the bottom of your cap to make sure that it matches the shape pictured.