With all of us experiencing the heavy cold snap, I noticed the product had turned to a "slushy" consistency at about 20 degrees Fahrenheit. From the reviews it seems they changed the recipe in recent years: was propylene glycol, glycerin, corrosion inhibitor - bottles now say water, ethyl alcohol...
Even my jug of winter windshield washer fluid remained completely fluid and didnt turn to a slushy.
Maybe it is a State by State issue having different regulations, but the reviews certainly seem to indicate it perhaps does not afford us all the protection we were expecting, e.g. -50 degrees burst.
Just an FYI and in case anyone else had any comments or thoughts.