This test method was developed to assess the performance of an engine oil to control engine wear and deposits under heavy duty operating conditions selected to accelerate soot production, valve train wear, and deposit formation in a turbocharged, aftercooled four-stroke-cycle diesel engine.

This test method may be used for engine oil specification acceptance when all details of this test method are in compliance. Applicable engine oil service categories are included in Specification D 4485.

The test method was correlated with field service data, determined from side-by-side comparisons of two or more oils in on-highway service. These data are contained in a research report.⁶ These same field service oils were used to develop the operating conditions of this test method.

The design of the engine used in this test method is representative of many, but not all, modern diesel engines. This factor, along with the accelerated operating conditions should be considered when extrapolating test results.

1.1 This test method is commonly referred to as the Cummins M11 High Soot Test (HST). The test method defines a heavy-duty diesel engine test procedure conducted under high soot conditions to evaluate oil performance with regard to valve train wear, sludge deposits, and oil filter plugging.

1.2 The values stated in SI units are to be regarded as the standard. The values given in parenthesis are for information only.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. See Annex A1 for general safety precautions.