ASTM D3525-20

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 problems and to take appropriate action.

1.1 This test method describes a gas chromatographic technique for determining the amount of gasoline fuel dilution in used lubricating oils arising from their use in gasoline engines.

1.2 This test method is limited to gas chromatographs accommodating wide-bore (0.53 mm) capillary columns and that are equipped with flame ionization detectors (FIDs) and temperature programmable ovens.

1.3 There is no limitation regarding the fuel dilution concentration range that can be determined by this method, however the precision statements apply only to the concentration range of 0.5 % to 20.3 % gasoline. A reporting limit of 0.5 % gasoline fuel dilution has also been included in the method.

1.4 Lubricating fluids recovered from engine crankcases have undergone changes due to heating, volatilization, sheering, oxidation and other reactions, and, as a result, the chromatographic profiles of the gasoline diluents and engine oils often differ significantly from their original patterns. Caution is accordingly advised when comparing quantitative determinations made using new verses used or in-service materials.

1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.6 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.

1.7 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.