I understand what you are saying about flow being the heat disapator. I think that even if there isn't as much flow back to them if they have no vapor there the coolant, even if it doesn't have a high flow rate, will disapate heat much better. According to Evans, by using their coolant your cooling system will not build more than 4 psi. The PSI in a cooling system is caused by vapors. Vapors are caused by a liquid reaching their boiling point, like water being heated to 212*. If you boil water on the stove you will notice that it will produce steam before it boils, which will build pressure in a closed system even before the 212* point. I do understand the concept, and the chemistry behind it I just don't know if it would make enough difference to save our trucks from this problem.

Doug