16psi Radiator Cap

Non-turbo Mirages run a 13psi radiator cap. Certain Mitsubishi cars run a 16psi cap that fits.

* Beware, there is at least one other style of radiator cap. The 2G turbo Eclipses use a cap with a larger center seal. *

This cap is a Nippon Denso part for a 3G (2000-2005) Eclipse GT (V6 model)

A higher pressure radiator cap will release coolant into the overflow container at a higher cooling system pressure.

Higher pressure coolant boils at a higher tempurature, making it able to absorb more heat from the engine (in some cases.)

If your cooling system is already at max pressure and the radiator cap is starting to release some pressure, boiling coolant will fail

to absorb as much heat as it could have. The heat and boiling raise the coolant pressure more and cause the situation to get worse.

This upgrade is not always needed, but I do not want the cooling system to be an issue on my car. Plus I live in Arizona and heat can be an issue.

A higher pressure radiator cap will destroy an old radiator hose that is worn out. It is a good idea to buy new hoses

when increasing the radiator cap pressure. On to the pictures!

Stock replacement 13psi (.9 bar) cap - 16psi (1.1 bar) cap from a 3G Eclipse