Yank all you like but I think you are missing the point he is not saying your engine will run cooler but what I think he is saying is that the mixture in the rad can reach a higher temperature the more anti freeze there is in the mixture before the onset of boiling occurs or at least this is the assumption I would make from what he says but then again I am only a mere mortal not a scientist.

Would it not be fair to say though that if the engine temp is running that close to boiling that rather than mess with chemicals it would be more practical to fit a more efficient radiator or move the one you have to a better place.