Good heads up, Ken! In general the author was right on, but there was one glaring factual error in the article, though:
"...The proper freeze point mixture also is the
most effective coolant, because the fluid’s ability to carry heat (heat capacity) is best at a 50/50 mix..."
The above quote from the article is simply wrong. Straight water has the highest ability to carry heat and exchange it at the radiator to the surrounding air when compared to any antifreeze/coolant-water ratio. Period. Unfortunately, straight water also quickly boils away and/or freezes-up, as well as promotes corrosion of the cooling system's metal components. A 50/50 antifreeze/coolant-concentrate and distilled water mix generally provides the best compromise in corrosion protection, freeze-up protection, and heat carrying ability in most areas. Conversely, running 100% antifreeze concentrate won't protect very well against corrosion at all - it needs 30% to 60% water content in the cooling system to adequately activate the corrosion inhibitors. Strangely, straight antifreeze/coolant concentrate will actually freeze sooner than a proper mix with distilled water, too. This is true for both conventional as well as extended-life antifreeze/coolant products. In really cold climates, up to a 70% antifreeze to distilled water concentration would provide the lowest temperature freeze-up protection. In year around hot climates, running 40% antifreeze to distilled water would offer adequate corrosion protection and enhanced cooling efficiency.
