5.1 Some fuel dilution of the engine oil may take place during normal operation. However, excessive fuel dilution is of concern in terms of possible performance problems. This method provides a means to determine the magnitude of the fuel dilution, providing the user with the ability to predict performance and to take appropriate action.

1.1 This test method covers the use of gas chromatography to determine the amount of diesel fuel in used engine lubricating oil. This test is limited to SAE 30 oil. The diesel fuel diluent is analyzed at concentrations up to 12 % by mass.

Note 1: This test method may be applicable to higher viscosity grade oils. However, such oils were not included in the program used to develop the precision statement.

1.2 This test method is limited to gas chromatographs equipped with flame ionization detectors and temperature programmable ovens.

Note 2: The use of other detectors and instrumentation has been reported. However, the precision statement applies only when the instrumentation specified is employed.

1.3 There is some overlap of the boiling ranges of diesel fuel and SAE 30 engine oils. Moreover, the boiling range of SAE 30 oils from various sources can vary appreciably. As a result, the calibration can be altered by as much as 2 %, in terms of fuel dilution. When testing unknown or mixed brands of used engine oil, it should be realized that the precision of the method may be poorer than the precision obtained when calibrating with a new oil representative of the used oil being tested.

1.4 The values stated in SI units are to be regarded as the standard. The values stated in inch-pound units are for information only.

1.5 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, health, and environmental practices and determine the applicability of regulatory requirements prior to use.

1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.