Hi Keith
Yes....and No. You are right that the boiling point will raise (Ethylene Glycol boils at c.140oC), but the efficiency of the heat transfer will reduce. So, whilst you have more latitude with temperature, you need it, coz the engine will run hotter. My quest is to keep the engine temperatures down, especially around the cyl head, and plain water is a much better heat sink. It is my understanding (and I'm not claiming to be an expert) that distilled water and the Silkolene coolant additive is the best way to go for racing engines. However, all I am trying to achieve is more efficient cooling at slow speed with the fans full on, and I'm hoping that plain water will do the trick. My confidence is such that I am definitely going to do some testing first! If I'm wrong, I'll confress on this forum.
Now, this stuff gets interesting in relation to fire (my favourite subject). Ethylene Glycol is flammable, though you would not expect a coolant leak to cause a fire. However, on the older Range Rover with the Rover V8 there was a problem with electrolytic action (see the Gates Hoses website) which was causing premature failure of some of the hoses. When the top hose split, the leaking coolant mixture would collect in the 'V' of the engine. The water would boil off, leaving the flammable antifreeze to slowly vapourise and ignite. That was a BIG recall!
Water wetter? Google it and see some of the reviews. I used it once, and the head gasket seeped coolant into the oil once it got hot. I had the shame of being towed around the Le Mans circuit back to the car park - I'm still red with embarrassment!
