the SAE entered into a contract to host the next meeting of the board. A nonprofit organization under the SAE was established, named "Lubricant Review Institute." Basically, the engine builders have supported this activity and wish the review of new oils by a board for approval and to insure they meet the classification on military specifications. This matter is still1 to be resolved because the military needs may be different from those of the commercial market National Bureau of Standards Special Publication 556. Proceedings of SOME VIEWS ON SUBSTANTIAL EQUIVALENCY J. A. Creedon The Lubrizol Corporation I appreciate this opportunity to participate in the panel discussion and to present some views on the subject of substantial equivalency specifically related to the entire test program which was recently completed on six selected re-refined oils. The purpose of the test program was to examine possible variations in re-refined oil basestocks and to estimate the effect of these variations on the ability of the blended product to qualify under existing U.S. military specifications. To accomplish this objective, six oils were chosen by a subgroup of the American Society for Testing and Materials (ASTM) Re-refined Oil Task Force and representatives from the Environmental Protection Agency and the U.S. Army. Six different re-refined lubricants were selected to represent quality levels ranging from "best" to "low." These oils represented products of differing chemical and physical properties, and the purpose of selecting various quality levels was to determine the effect on overall engine performance. Two lubricants were represented as being of the so-called "best" quality, three in the middle category, and one representing the poorest or low level. Recommendations were then received relating to additive treatment. All six lubricants were formulated with a single additive package at a specific treating level and subjected to engine sequence and Caterpillar 1-H2 tests. A review of the test data obtained indicates several interpretations are possible (table 1). The first, and perhaps most obvious, approach is to look at the data on an overall basis to determine whether or not a specific lubricant would meet the requirements of the MIL-L-46152 specification. Another approach would be to evaluate the lubricants on a pass/fail basis relating to each individual test which was conducted. Still another possibility would be to look at the overall program based on assessment of the individual performance criterion involved--specifically, such items as top groove filling, bearing weight loss, engine rust, wear, viscosity increase, sludge deposits, etc. Also, it would be of interest to look at the data and relate the results to the quality levels of the base stock which were assigned to these lubricants by the ASTM Re-refined Task Force. Table 2 shows the finished oil inspection data on these six lubricants for additive component levels and viscosity levels prior to engine performance testing. The first approach in interpreting the data relating to the MIL-L-46152 specification would indicate that only one of the six lubricants could be considered as meeting the qualification requirements of the specification. Reviewing the data on the basis of the number of tests involved, a somewhat different picture is found; namely, that, of the 6 oils evaluated which were run on 30 different tests, 25 of the tests met the MIL-L-46152 requirements and 5 failed to meet the acceptance limits. The 30 tests involved 114 different numerical requirements which the lubricants must meet. Reviewing the data on this basis, the 6 lubricants met 109 numerical requirements and failed 5. Another possible method of reviewing the test data on a pass/fail basis pertains to a comparison with the quality levels assigned to the basestocks by the ASTM Re-refined Task Force (table 3). Viewing this test program in this fashion shows that all of the oils passed the L-38 and IIC tests. The one lubricant, L-852, meeting MIL-L-46152 performance was considered to be in the middle category with respect to base oil quality. The two oils represented as being "best" failed the 1-H2 test. A broad assessment of the test data points to the following potential strengths and weaknesses. The strengths relate to IIIC deposit control, both from the standpoint of sludge and varnish as well as oxidation resistance as measured by the viscosity increase in the IIIC test. The only possible exception here is with oil CCL-850, which gave a viscosity increase at 64 hours of 4,774 percent with an acceptable answer at 40 hours of 126 percent. This was the only lubricant which gave excessive viscosity increase even at 64 hours. The other oils ranged from 103 to 173 percent at 64 hours. All of the lubricants also exhibited acceptable valve train wear control as measured by cam and lifter wear in the IIIC test. Without exception, all of the lubricants exhibited satisfactory IIC antirust protection. With respect to the L-38 test, although there was some variation in the bearing weight loss, the results indicate comparable performance from the standpoint of adequate copper-lead bearing corrosion protection. The VC test results also showed satisfactory performance from the standpoint of overall sludge and varnish deposits. The potential weaknesses of the formulations tested appear to be in the area of 1-H2 lacquer deposits where three of the six lubricants failed to meet the U.S. military MIL-L-46152 requirements. There also appears to be some indication of possible marginal performance with respect to piston varnish in the VC test. The test program involving these six lubricants has provided a substantial amount of useful and significant information. However, in any program of this type there are obvious limitations. For example, it was felt necessary in this program to utilize a single additive system, as well as a given additive treatment. addition, due to cost limitations, a single evaluation was made on each test procedure which does not allow assessment of test repeatability. In To summarize, we believe the test data developed demonstrate the capability of these six lubricants to meet the military specification requirements with a given additive system. As we have shown, there are several ways to interpret the data, any one of which may have equal validity. Also, the data suggest that re-refined oils do have satisfactory performance potential to be utilized in formulating lubricants to meet the U.S. military specification requirements. The test data obtained relate to a single additive type and treating level; therefore, the conclusions reached must be confined to a discussion of the re-refined oils within these parameters. It is well known that to obtain satisfactory performance potential on re-refined oils it is necessary to establish adequate quality control of raw materials, as well as re-refining and blending processes. This can, however, be accomplished and has been satisfactorily demonstrated by the program established and operating in South Africa under the South African Bureau of Standards. To achieve the maximum amount of information relating to the performance differences in re-refined stocks, the present program should be expanded to include other types of additive chemistry and variations in additive treating levels. This, we feel, is particularly important to adequately determine and define the performance of individual re-refined basestocks. Significant progress has been made to achieve the original purpose of this program, which was to "examine variations in re-refined oil basestock and to estimate the effect of these variations on the ability of the blended product to qualify under existing military specifications." Additional work, however, needs to be done, and it is recommended that the responsible groups review the progress made to date for the purpose of setting up additional test programs to fully accomplish the program objectives. |