What's the advantages of using a high pressure radiator cap?

or the STi brand radiator cap?

 

A higher pressure cap means that the coolant, under more pressure, has a higher boiling point. This means its got to get hotter before it boils (obviously) On a road car there is little point as its never going to get that hot if everythings working as it should.

One thing to remember is that more pressure means the pipework and rad. is under more stress. Something could be a "weak link".

 

Thanks for that.

Are the STi brand radiator cap's a high pressure radiator cap?

 

Indeed it is, 1.3 bar relief pressure as opposed to 0.9 bar relief on standard radiator cap.

 

However it will serve no purpose unless you are boiling your water at the current pressure cap setting.

 

And if you are boiling your engine coolant, I would surmise there is a serious engine problem!

So why do STi make 'em,?

Ta