This past Sunday, Johnpro, JeffTepper & I were at a local Nor Cal car show that gave us a wonderful temp of 107 degrees. 3pm, I was getting tired and cranky and decided to head home. With 75% distilled water, 25% coolant, bottle of water wetter, crossflow 4 core desert cooler radiator, 180 stat in Red, the coolant temp averaged 184. Very happy.