Abstract: Most engine oils are made to acceptable standards of quality. Even so, they can vary widely both in general and in particular qualities. Then, of course, there are engine oils that are of poor quality and put on the market for reasons of ignorance or greed. Unfortunately, for the uninformed automobile owner, an engine oil of appropriate quality and one of poor quality both look and feel the same. Without an alternative source of reliable information regarding engine oil quality, the automobile owner is left with his engine being the recipient and witness of a good oil's benefits or a poor oil's costly adverse engine effects. One of the purposes of this paper is to bring attention to an alternative source of informaition on engine oil qualities. In addition, the paper will show several examples of how such information can be used to more broadly observe the benefits and limitations of formulation and manufacturing practices resulting in the broad range of available engine oil quality.