is suppost to do just that, I had some of that new, mixes with any type or color, prestone, as an extra bottle, mixed properly 50/50, tested to -45 , and at -2 it was slushy, but still tested at -45 so I used a diffrent tester same thing, just glad it wasn't in my moter. All I can figure is that it was a messed up bottle (chemically). Anybody else have this issue?