Water turns to a vapor or boils at 212°F.  For every pound of pressure we put water under, it raises the boiling point 3 degrees.  15 lbs of pressure would raise the boiling point of water from 212°F to 265°F.  (These numbers are all altitude sensitive.)  So 15 lbs of pressure created by the radiator cap multiplied by 3.5 degrees will move water’s boiling point upwards 45+ degrees. So under pressure, your radiator liquid will boil at 245-265°F and not at 212°F.


A large percentage of the engines that are replaced by professional technicians have been damaged beyond repair because of overheating.  Others ran low on oil and some simply were worn out.

If you are thinking – If a 50/50 mixture is good, then 70/30 has to be better – get that idea out of your head immediately!  Any deviation of this 50/50 mixture will do nothing to make your hot or cold protection any better.  100% coolant will cause your engine to overheat because 100% coolant cannot dissipate heat.  Too much coolant can cause your engine to overheat because, like epoxy (or gravy), you need two components in the right amount to accomplish your goals.

The pressure tester to check the performance of your radiator cap is about 20 times the cost of a new cap, so replace the radiator cap with a name brand cap when you service your cooling system.

When servicing your cooling system, be sure to use a good flush to clean and remove the trash from your system.  Rinse well with clean water.  Then pick an appropriate coolant or antifreeze. You can enhance the properties of your coolant by using a water pump lubricant or rust inhibitor that will not damage your seals and gaskets.