J300_202405 Engine Oil Viscosity Classification

This revision includes multiple revisions to the standard. First, an additional acceptable method for determination of low shear rate kinematic viscosity at 100 °C, ASTM D7945, has been introduced. The inclusion of an additional method can enable engine oil producers to improve logistics and quality assurance. The equivalence of ASTM D445 and ASTM D7945 in determination of kinematic viscosity at 100 °C for a wide variety of engine oil formulations within the viscosity range covered by the current SAE J300 Standard has been demonstrated in the ASTM Research Report RR:D02-1797 and the ASTM Research Report RR:D02-2057.

Additionally, this revision clarifies editorially the Low-Temperature Cranking Viscosity requirements for SAE xW grades in Table 1 and related text, while the title for ASTM D5293 referenced in SAE J300 has been updated to align with the current method title. Finally, ASTM D4683 has been defined as the referee method for high-temperature high-shear-rate viscosity.