SAE J300, first issued in 1911 and revised as recently as April 2021, is the cornerstone for classifying engine oils based on their rheological properties. This global standard is crucial for lubricant blenders and manufacturers worldwide, providing a foundation for formulating and labelling engine oils that meet modern engine demands.
SAE J300 defines engine oil viscosity grades, categorising them into single grades and multigrades. The standard outlines two series: W grades for low-temperature performance and non-W grades for high-temperature performance.
W grades must maintain fluidity at low temperatures to ensure proper lubrication during cold starts. SAE J300 specifies maximum cranking viscosity (ASTM D5293) and pumping viscosity (ASTM D4684) for W grades, measured in milliPascal-seconds (mPa·s).
High-temperature viscosity influences oil film strength and thermal stability. SAE J300 specifies kinematic viscosity at 100°C (ASTM D445 or bias-corrected ASTM D7042) and high-temperature high-shear-rate (HTHS) viscosity at 150°C (ASTM D4683, D4741, or D5481) for non-W grades.
Multigrade oils (e.g., 10W-30) offer versatile performance across a broad temperature range, meeting both low- and high-temperature requirements. They’re ideal for year-round use in varying climates and are predominant in the market, obtained by adding Viscosity Index Improvers (VII) to the formula.
The SAE J300 standard has been continuously updated to meet evolving industry needs. Recent revisions have extended the classification system to include lower high-temperature high-shear-rate (HTHS) viscosities, adding new grades such as SAE 16, SAE 12, and SAE 8. These additions support the ongoing quest of Original Equipment Manufacturers for improved fuel efficiency.
Proper labelling is essential for SAE J300 compliance:
- “SAE” must precede the viscosity grade number
- Multigrade oils: W grade first, followed by non-W grade (e.g., SAE 10W-30)
- Oils not meeting viscosity grade requirements must not bear an SAE viscosity grade label
SAE J300 offers a crucial, global framework for how all market stakeholders identify viscosity. It allows oil marketers to legitimise their products via standardisation and provides OEMs and end users with confidence that service fill lubricants meet recommended criteria. This standardisation is vital for maintaining consistency and reliability among lubricants, especially as the industry trends towards lower viscosity formulations.
Understanding SAE J300 is crucial for the lubricant industry. By adhering to these standards, we ensure our products deliver the reliability and efficiency modern engines demand globally.
Trust Valorem Chemicals to be your partner in achieving excellence in lubricant formulation and performance.