STP81: Petroleum Lubricating Oils as Related to Automotive Equipment

    Larson, C. M.
    Chief Consulting Engineer, Sinclair Refining Co., New York, N. Y.

    Pages: 19    Published: Jan 1948


    Abstract

    The petroleum industry, having spent hundreds of thousands of dollars for fundamental research in the pure hydrocarbon field has found that the manufacture of automotive lubricating oils today is still more of an art than a science. Petroleum, Fig. 1, made up of many complex types of mixed organic hydrocarbons, is the raw material used to make lubricating oils. The carbon atoms can combine and recombine with each other in many different ways as well as with many elements such as hydrogen, oxygen, sulfur, nitrogen and other inorganic substances. It has been estimated that in an S.A.E. 30 motor oil range the possible combinations of hydrocarbon compounds, due to the action and reaction of the various carbon atoms in that mixture, could run into millions. When you hear statements such as those of Frederick Rossini that it took 200 man years of research to isolate 72 hydrocarbons from Midcontinent crude, then you realize how complex the situation is in comparison to inorganic substances and their reactions and why the long standing physical and chemical specifications of lubricating oils are giving way to performance specifications. Performance specifications require a statement or guarantee of future performance in service based on “life test” approvals made under actual or similar operating conditions. There was a time when automotive lubricating oils were specified by physical limits measured by rather simple A.S.T.M. laboratory test methods such as flash, fire, viscosity, viscosity index, pour, and Conradson carbon, but at that time the inherent factors of safety in the proper selected lubricating oil were far beyond the requirements of the engines, gears, or bearings. A special Subcommittee on Oil Purchase Specifications of Committee D-2, reported that “There is not nearly enough reliable information now available as regards test methods to permit workable oil purchase specifications which would, within themselves and without performance tests, serve as a reliable guide in the selection of lubricants.” Laboratory tests are not safe guides to service performance. In most instances, the best refined lubricating oils or those known research samples of pure hydrocarbons need inorganic substitution compounds or metallo-organic additives and other organic inhibitors to enable them to meet the service requirements of greater energy, force, and motion imposed upon these automotive lubricating oils.


    Paper ID: STP47906S

    Committee/Subcommittee: D02.B0

    DOI: 10.1520/STP47906S


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