What is the freezing point of 100 percent Antifreeze?

Answer 1

Original Answer: 100 percent coolant freezing point -60 celcius

This is baldly incorrect. 100% solution of ethylene glycol-based antifreeze is approximately -12 degrees celcius, higher for many of the lower quality products (which have a lower concentration of ethylene glycol). The optimum solution is about 60% antifreeze and 40% water. The reason for this is that the two molecule types (ethylene glycol and water) interfere with each other's ability to attract like molecules and crystalize, or freeze. A higher concentration of either liquid will reduce this affect and raise the freezing point.

For warmer climates, 20% antifreeze is probably enough - water has a higher capacity for heat than antifreeze does. Running 100% water is not a good idea though, even in the hottest of temperatures. There are (usually) additives in antifreeze that serve to condition and lubricate the cooling system, primarily the water pump.

Pure ethylene glycol actually freezes at about 8 degrees fahrenheit.. The key is in the mix.