Q: What is the difference between Dex-Cool and regular green or an antifreeze that will mix with any color or make? What would happen if you added a 50/50 prestone that mixes with any color to a system that calls for Dex-Cool? Thanks in advance!
A: For practical purposes there are two types of coolant used in most cars, although some Euros specify low-silicate standards for their vehicles. There is ethylene glycol (the old technology “green” type) and OAT (organic acid technology) type.
OAT is most commonly used today and they are the “long-life” or “extended-life” type. Color is a dye added to a basically colorless chemical compound; each manufacturer is fond of their color.
I would recommend draining the system and flushing it completely if unsure of the type. Prestone, Peak and most of the other major or house brands sold by your parts jobber will work fine in a 50-50 blend with distilled water.
– Jim O’Neill
