What Is a SAE 30 Oil?

By Lexa W. Lee
SAE 30 motor oil keeps engines running smoothly.

SAE 30 oil is a motor oil that has been given a viscosity rating of 30 by the Society of Automotive Engineers, according to AA1Car Automotive Diagnostic Help Center. Motor oils typically have ratings from 0 to 50.



Viscosity

Viscosity is a measure of how well an oil pours at a given temperature. Viscosity is sometimes referred to as weight. A low rating means a thinner oil, while a high rating means a thicker oil.

Performance

Thinner oils perform better in colder weather, especially when starting a car. Thicker oils perform better at higher temperatures. Single-grade oils, such as SAE 30, are thicker than lower grades, and in this case has a viscosity rating of 30 at a temperature of 100 degrees Celsius.

Use

SAE 30 oil is typically used for smaller air-cooled engines, like the ones in small tractors, lawnmowers, and chain saws. Most motor oils today are multi-grade oils that will perform well in all seasons.

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.