What Is the Difference in Antifreeze for Deisel Engines & Gas Engines?

by Lexa W. Lee

The difference between the antifreeze used in a diesel engine and that used in a conventional gas engine is that diesel antifreeze contains a special additive that protects against erosion on cylinder walls.

Cavitation

Cavitation occurs when high-pressure vapor bubbles that form in the cooling system attach to, implode and erode the wall of the cylinder in a diesel engine. Gasoline engines typically operate under lighter loads, have much lower cylinder pressures and do not require protection against cavitation.

SCA

Diesel antifreeze contains SCAs, or supplemental coolant additives. They prevent cavitation by forming a protective barrier between the cylinder wall and the vapor bubbles. Erosion affects the SCA coating instead of the cylinder wall.

Additional Benefits of SCAs

SCAs also neutralize acids, provide anti-foam protection and prevent scale and corrosion. The coolant system should be tested at least two times per year as part of engine maintenance. This is usually done with a refractometer or hydrometer.

About the Author

Lexa W. Lee is a New Orleans-based writer with more than 20 years of experience. She has contributed to "Central Nervous System News" and the "Journal of Naturopathic Medicine," as well as several online publications. Lee holds a Bachelor of Science in biology from Reed College, a naturopathic medical degree from the National College of Naturopathic Medicine and served as a postdoctoral researcher in immunology.