been looking at this myself because of my hot running problem. Extract below is from Redline's site (
http://www.redlineoil.com/redlineoil/wwti.html) and is directly on-point........
"Water has amazingly superior heat transfer properties compared to virtually any other liquid cooling medium - far superior to glycol-based coolants. As shown in Table 1, water has almost 2.5 times greater thermal conductivity compared to glycol coolants. Mixtures of glycol and water have nearly proportional improvement due to the addition of water. Most heat is transferred in a cooling system by convection from hot metal to a cooler liquid as in the engine block or from a hot liquid to cooler metal surfaces, as in the radiator. The convection coefficient of liquids in a tube is a complicated relationship between the thermal conductivity, viscosity of the liquid, and the tube diameter which determines the amount of turbulent flow. Since 50/50 glycol solution has about 4 times the viscosity and only 70% of the thermal conductivity of water, the thermal convection coefficient for a 50/50 glycol solution is approximately 50% of the coefficient for water. Water in the cooling system is capable of transferring twice as much heat out of the same system as compared to a 50/50 glycol coolant and water solution. In order for a 50/50 glycol mixture to reject as much heat as water (amount of heat rejected is independent of the coolant), the temperature differentials at the heat transfer surface must be twice as great, which means higher cylinder head temperatures. "
24-Jun-2003, 15:58 
Hybrid Mode
