Rad Caps??

Thanks...still looking for the pressure system answer.

Why is the caps PSI important?? I know that it makes your system like a "pressure cooker" and that the higher the PSI cap..will increase the boiling point temp. So why not use a MAX PSI cap and to lower the overall temp as max as possible. Wouldn't a system with a higher boiling point reduce the overall pressure in the system preventing due to less boilover, leaks and high overheating temps?


What don't I understand here about this phyics stuff and why is it standard to have a 16 - 18 PSI Cap..