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A method has been developed for expressing ASTM Sequence IIIE oxidative thickening in terms of test hours to 375 percent viscosity increase (PVI), instead of by PVI at 64 hours, for use in data handling. Expressing results as hrs-to-375 provides a needed transformation for PVI, and enables clearer and more accurate tracking of PVI results. The method has been approved within ASTM for use in proposed Severity Bias Estimate and Multiple Test Acceptance Systems. Use of hrs-to-375 is expected to be required soon.

An ASTM Task Force was formed in 1979 to improve the discriminatory abilities for engine sludge deposits and valve train wear of the ASTM Sequence V-D test. Several statistically designed programs were conducted to identify procedural and hardware items to achieve the stated objectives. The 2.3 liter, four cylinder test engine was updated with electronic fuel injection and high swirl combustion chamber technology. Of the parameters evaluated, increased test length, adjustments of temperatures and control of the rocker cover temperature had the greatest impact on increased test severity. A procedure has been developed that better discriminates between known good and poor engine oils. Field correlation has been improved and expanded to include European experience. An extensive program has been planned to establish field correlation and test precision.