Methods presently in use by the Penn Central Railroad for draining diesel locomotive engine crankcases are discussed. We believe these criteria apply to other types of diesel as well as gasoline engines. The author explores the use of oil insoluble values as limiting factors of an oil's effective life.
The effectiveness of blotter spot interpretations and their meaning in evaluating the condition of used lubricating oil is pointed out. Although controversial, the author feels it as well as later modifications of the technique can be most meaningful to the engine fleet maintainer.