Coolants
Background & Properties
castrol.com/GPS
800 255 4417
May 2025
GPS
Types of Coolants
Propylene Glycol Antifreeze
A less toxic coolant than ethylene glycol, Propylene Glycol Antifreeze is much more expensive. It must be
disposed of just like any other more toxic coolant product and is not as efficient at dissipating heat as
ethylene glycol.
Recycled Antifreeze
Recycled Antifreeze is available for a number of coolant systems and is typically a lower quality product. It is
sold mainly on price and exudes a burnt smell when used.
A Word on Extended-Life Antifreezes
Extended-life antifreezes usually require only one service during coolant life. For example, Castrol Radicool
SF-O can be used for up to 1,000,000 miles or 20,000 hours.
Although regular duty and extended life antifreezes are compatible, it is not recommended to mix the two.
e regular antifreeze negates the extended service characteristics of the long life fluid. It is best to drain the
system and fill with only one coolant type.
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