ASTM D6922 Test Method for Determination of Homogeneity and Miscibility in Automotive Engine Oils
4. Summary of Test Method
4.1 Visual color determinations and observations are made on an undiluted test oil specimen, along with six blends of the same test oil that have been combined with specific reference oils. The pour point is then determined for the undiluted test oil specimen and the six blends. The undiluted test oil specimen and six blends are then allowed to warm to room temperature. Color determinations and observations are again made on the undiluted test oil specimen and six blends. The undiluted test oil specimen and six blends are heated to 232°C, then allowed to cool to room temperature, and then stored at their pour point temperatures for 18 to 24 h. The undiluted test oil specimen and six blends are then allowed to thaw and a series of color determinations and observations are made as they reach room temperature. All data are recorded on a report form.
5. Significance and Use
5.1 It is important that engine oils from different manufacturers be homogeneous and miscible with each other, because operators of automotive engines often do not have prior knowledge of the manufacturer of the oil that is currently used in their application, and engine failure can occur if oils are combined that do not stay homogeneous and function properly.
