The answer: consult your owner’s manual for proper antifreeze specifications.
I have an old '65 cuda and it needs a 50:50 solution, I went too heavy on the antifreeze once and it ate right through the water pump. But those were the days when you were always boiling over and adding water at the gas station. These days, you can’t even find a gas station with a water hose.
AFAIK, modern engines are designed to run on 100% antifreeze. Or at least, that’s how my '96 Toyota works.
Anti-freeze/coolant mix is important. Pure in-the-jug AF will freeze at about 11 degrees below zero F. Mixed with water in a fifty- fifty mix it will protect downto -34F. Pure AF is also thicker than water and will not allow proper heat transfer. If it matters I was a NIASE certifed mechanic. I let it lapse.
Which model? A call to my Toyota dealer says they know of no model that is supposed to be doing that - especially since the important mixture of the two is best on both the cold and the hot sides of the scale…?
I know of no “modern engines” that are supposed to be running on 100% antifreeze.
And there is also:
These guys have a simple explanation, without getting into the chemistry involved.