[fiveohpatrol]

well the boiling point of pure water (which we all know that tap water isn't exactly pure) is 212 degree's F. So if you run straight water then you better make sure you don't get much over 200 degrees.

Antifreeze will raise the boiling point (and lower the freezing point, duh) of water, but it makes it less efficient in transferring heat.
I run about 20-25% antifreeze with the rest water in the summer. And about 50-50 mix in the colder months.

hope this helps some,
-Drew