[Ed in Maine]

When you add anti-freeze to the water it lowers the specific gravity of the solution. In other words, the weight of a gallon of 50/50 solution is less than a gallon of plain water. It makes the solution leak out easier than plain water. I don't like the coolant blowing back onto the firewall from the water pump and I don't like to take the risk of head gasket seepage into the crankcase. I use plain water with Prestone Anti-Rust and Water Pump Lubricant. In Florida this coolant is just fine. In Maine, I mark my calendar to drain the water/anti-rust solutions in mid October!!

At the Model A National Meet in Georgia in 2019, a speaker mentioned that distilled water tends to absorb minerals from the metals in the radiator and is not recommended. Of course always use distilled water in your battery. Ed