The addition of antifreeze, which is also an anti-boil, in fact diminishes the coolant properties of water.
PLEASE NOTE: The above is specific to the ability of the coolant to absorb heat . Just because it increases the boiling point does NOT mean it is a better coolant.
Thus, for maximum cooling efficiency a lower percentage of antifreeze is better. When I asked Bill at Ron Davis radiators in Arizona what to use in my new aluminum triple-pass they built for me, he said he personally recommends a 25% antifreeze mix; 25% will protect from freezing down to 10 degrees. The only additive Ron Davis Radiators recommends is Red Line Water Wetter.
Antifreeze is usually used in automotive coolant systems to ensure against engine damage caused by the freezing of the coolant. Likewise, it will increase the boiling point of the coolant, protecting the engine from heat damage (that is, steam pockets).
A 50%/50% mixture with water, in a system with a 15 pound pressure cap, lowers the freeze point to about -34 degrees, while raising the boiling point to about 270 degrees.
Antifreeze also contains rust inhibitors and water pump lubricants; but these can also be obtained as a separate additive not incorporating any antifreeze properties.
Pressurizing the coolant system will also raise the boiling point of the coolant. Panteras came stock with a 16 pound pressure tank on the surge-swirl tank. The overflow tank does have a cap, but it was not and should not be a pressure cap.
As the coolant abilities of water are diminished - that is, the % of antifreeze used is increased - the flow of the coolant needs to be increased to maintain the baseline coolant properties. This is in the range of 15% for a 50%/50% mix. In other words, if pure water keeps temperature at 180 degrees, when using the 50/50 mix you would need to increase coolant flow by 15% to maintain that 180 degrees.
Pressure - antifreeze % - coolant flow all interact on final coolant efficiency and performance.
Larry - flame suit on...
