Base oils are the fundamental building blocks of lubricants, forming the foundation for a wide range of automotive and industrial oil formulations. Among the various types available, SN 500, SN 350, and SN 150 are some of the most commonly used solvent neutral base oils, categorized primarily by their viscosity levels and refining processes.

SN 150 is a light-grade base oil with low viscosity, making it suitable for applications requiring excellent fluidity at low temperatures. It is commonly used in the production of engine oils, gear oils, and other lubricants that need to flow quickly and maintain performance under lighter loads or cooler environments. SN 150 also offers good oxidation stability and solvency, which helps in controlling sludge and deposit formation.

Moving up the scale, SN 350 offers a balanced viscosity profile that lies between SN 150 and SN 500. It is often used in blended lubricants to achieve specific performance characteristics. This mid-range base oil is preferred in industrial oils, transmission fluids, and process oils where moderate viscosity is essential. Its versatility allows formulators to tailor products for a range of mechanical systems and conditions.

SN 500 is a heavier base oil with higher viscosity, ideal for applications that require thicker lubrication films and better load-carrying capabilities. It is widely used in the formulation of heavy-duty engine oils, gear oils, and hydraulic fluids. SN 500 offers excellent thermal and oxidation stability, ensuring prolonged oil life and enhanced equipment protection under high-stress operating conditions.

All three grades — SN 150, SN 350, and SN 500 — are refined through solvent extraction and dewaxing processes to remove impurities and improve performance. They are typically classified as Group I base oils, known for their good solvency and cost-effectiveness. While Group I oils are suitable for many traditional applications, they are often blended with additives or higher group oils to meet modern performance standards.