this is an interesting subject... when I was younger, I was taught that pure water has a higher boiling point than antifreeze, and thus on a hot day, pure water would cool better. Antifreeze was only invented so the water would not freeze.
water has a boiling point of 100*C (212*F)
and when you buy a bottle of antifreeze, right on the back it has mixing directions and specifications of temperature range per solution percentage.
And I was interested to find out that for every percentage of mixture with antifreeze (with Ethylene Glycol) the boiling point is raised higher than what pure water would have. For example, with a 50/50 mixture, the boiling point is raised to 129*C (265*F)
and as I understand it, when heated up, antifreeze does not evaporate under pressure, unlike water which has a greater tendency to evaporate under pressure?