Yup you are absolutely correct I just looked that up I am mistaken. It will cool the object faster but will not exceed the real feel temp. So more than likely it's the type of antifreeze and the ratio that's causing the freezing.I agree with everything you say except for the windchill part. Nothing can get colder than the actual outdoor temp. Windchill just helps it get there quicker. The windchill factor is how cold it feels versus the actual temperature that you will cool down to.