Originally Posted by OTRtech
Someone correct me if this is inaccurate.It was explained to me many years ago that straight antifreeze would freeze at a higher temperature than antifreeze mixed with water.
I've had unopened jugs of Prestone freeze at -25 sitting next to a gallon of mixed 50/50 that flowed fine.
Correct, to the best of my knowledge, and I believe straight anti-freeze has less high temperature tolerance as well.
Straight antifreeze needs dilution, but they do also sell pre-mixed 50/50 antifreeze/water.
The advantage of buying it straight is that you can tailor percentage dilution to your particular climate/temperature requirements.
P.S. Cold snap in Canada, NE US just coming to an end - temps up here ranged -15 to -25 C for about a week; with wind chill, subtract about another 10 degrees C or so; don't know exactly how that translates to Fahrenheit, but it was darn cold.