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Why Go OAT?


A typical antifreeze/coolant formulation is 96% water and glycol. However, the remaining 4% is important and can have a lasting impact on a heavy-duty diesel engine.

In heavy-duty diesel engine applications, coolant/antifreeze is formulated to prevent liner cavitation in wet sleeve liners and also protect against scale, corrosion and hard water deposits.

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TypicalAntifreeze/Coolant Composition

Wet-SleeveLiner Cavitation: Cavitation occurs in wet-sleeve linersfrom rapid formation and collapse of vapor bubbles

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caused by vibrationsoccurring as the piston moves up and down. High pressures generated in verysmall areas cause the collapsing bubbles to hammer the liner and effectivelydrill small holes into the liner wall. Coolant additives, referred to asinhibitors, prevent this catastrophic occurrence by forming a hard surface onthe liner wall that shields the metal.

Inhibitors: There are two general categories of inhibitors: inorganic and organic. Organic acid technology (OAT) inhibitors are preferred by today’s original equipment manufacturers (OEMs) and eliminate the need to add or maintain supplemental coolant additives (SCAs). OAT inhibitors are opportunistic by moving to trouble spots as needed and selectively protect the cooling system, resulting in longer-lasting protection.

Conventional inhibitors are typically comprised of inorganic molecules that act quickly and cover all components throughout the cooling system. Unfortunately, they also deplete quickly and result in short-lived protection unless SCAs are added periodically.

Go OAT: FS Extended Life OAT Antifreeze/Coolant

FS Extended Life OAT Antifreeze/Coolant is a premium organic acid technology (OAT) coolant that is formulated for heavy-duty and light-duty diesel and gasoline applications.

Additional Benefits:

  • Eliminates the need for supplemental coolant additives (SCAs) and coolant filters
  • Provides superior long-term elastomer compatibility
  • Prevents pitting caused by cavitation and corrosion of brass, copper, solder, steel, cast iron, and aluminum
  • Extended service life – up to 1,000,000 miles | 8 years or 20,000 hours protection
  • Free of phosphates, silicate, nitrites, amines, and borates
  • Compatible with most major OEM brands of extended life coolant
  • Provides maximum freeze up and boil-over protection
  • Available as pre-diluted (50/50) or as concentrate
  • NOAT Extended Life Coolant is also available (contains nitrite; up to 1,000,000 miles | 20,000 hours or 8 years protection; does require an extender at 500,000 miles)

Sticking with Green?

If you have been maintaining vehicles for decades, it is easy to stick with what you know when it comes to cooling system fluids: conventional “green” antifreeze. The maintenance practices are easy to remember: replace every 12 months or 12,000 miles. But the old standard green isn’t the best coolant for modern engines, and misusing it can even cause damage!

Here are three things to consider if you are sticking with green:

1. If you are using it in a vehicle with the model year 1996 or newer, you are likely using sub-optimal antifreeze for your system: most automotive makes of these model years use organic acid technology (OAT) antifreeze due to the high aluminum content of their cooling systems.

2. Sticking with conventional technology antifreeze can be more costly: the increased maintenance compared to OAT antifreeze/ coolant can cost time and money.

3. Using conventional “green” antifreeze/coolant in heavy duty applications can cause catastrophic damage in the form of liner pitting/cavitation. Review manufacturer recommendations: you typically need to add an SCA to green antifreeze to use it in heavy duty applications.

-Reference: KOST USA; “Sticking with Green” quoted from KOST USA

Visit for more information or contact your local FS Energy Sales Specialist to Go OAT.

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