A Critical Assessment of the Low-Temperature Viscosity Requirements of SAE J300 and Its Future

The low-temperature portion of SAE J300 Engine Oil Viscosity classification has been analyzed in terms of its scope and its use by domestic engine manufacturers. Also, its ability to protect against pumping failures has been analyzed. The analysis shows that the use is not in accord with the stated scope, and that protection against pumping failures is not adequate for a significant portion of engines. An alternative scope for J300 is proposed which is based on minimum-use temperatures for each grade. The results of this analysis will assist in formulating a future revision of SAE J300 based on the results of the ASTM Low Temperature Engine Performance program.