Hello from SE PA. Where it was 93F on Tuesday or Wednesday, 85 or so Thursday and Friday, but is now in the 50s and raining. Weird. As Dick mentioned, running pure coolant is a no no. That's because the absolute best heat transfer agent (coolant) is water. Pure H2O! Of course the problem is that water will promote corrosion and rust. It also freezes in winter and boils in summer. So we add enough ethylene glycol (anti-freeze) to dramatically reduce corrosion/rust, lower the freezing point, and raise the boiling point. A 50/50 mixture is usually recommended because, as others have said, more anti-freeze does NOT improve the situation. Those in warm climates could run pure water and add rust inhibitor/water pump lube, but that stuff may not be available anymore. You may benefit from a product called "Water Wetter" by the company Red Line Synthetics. This stuff, added to water in the cooling system, is supposed to dramatically improve the heat transfer properties of the water. Red Line is well-respected and not a Snake Oyl hawker. Their SI-1 injector cleaner, detergent based instead of solvent based, is very highly regarded. Check out their website at: www.redlineoil.com Pete in PA