It should be on IC engine owners “Bucket List” to run 100% water 50/50 coolant 0% water propylene glycol
From my engineering days:
I can tell you 100% water cools better but is prone to corroding and freezing ( DUH) 50/50 has a higher boiling point, doesn't freeze except in EXTREME temps 100% propylene glycol will not cool as well but will lower the freezing point