I'd really like to meet Gustave one day. He seems to know quit a bit about performance BMW's.
http://e30m3performance.com/myths/mo...ter_wetter.htm "First we must dispel a common misconception: "Water Wetter" is not designed to lower your car's bulk coolant temperature. So if you put it in your E30 M3 hoping to see lower operational coolant temp's, then you will probably be disappointed.
"Water Wetter" is designed to reduce hot spots in your cylinder head. It does this by reducing the build-up of water vapor in any superheated areas."
"An additional benefit of using "Water Wetter" (in conjunction with 100% water) in you cooling system is that water has an extremely high heat capacity. Thus a gallon of 100% water can carry more heat away from you engine than an equivalent gallon of 50/50 water and coolant. Water also has a high thermal conductivity which increases the convection of heat away from the coolant passage walls and into the free stream of the liquid flowing through the passages."
When I flush my radiator this summer I'm going to go with 100% distilled water and a thing of water wetter.