Task Group Study of Extended Time PEI Tests on an Oil Matrix ESCIT Meeting 2007 August 9 Midland, Michigan Presented by: Ted Selby Task Group Chair

Scope and Objectives: Scope 1.The Scope of the Phosphorus Emissions Bench Test Task Group is to determine the optimum test length for the PEI(165) protocol to obtain best correlation with field and engine tests. 2.The Scope of the Task Group also includes the setting of Objectives. Objectives 1.To determine, through designed bench studies utilizing the Selby-Noack instrument, the optimum test length that will provide best correlation with data from taxi fleet and engine data. 2.To report the data gathered to the parent ESCIT group with recommendations regarding a subsequent round robin conducted under the auspices of ASTM Committee D02 and its Subcommittee B, Section 7.

Background: Task Group appointed at previous ESCIT meeting, June 14 th

Oils included in the study were selected by Task Group based on two criteria: 1.Oils would include ZDDP products from all four manufacturers. 2.Oils should, if available, carry some background engine performance data.

The PEI testing matrix was selected as being: All of the 16-hour tests had been run on either the newly submitted matrix oils or on their previous samples, so the 16- hour runs were not repeated. No 64-hour tests were scheduled until the matrix to 48 hours was completed (July 31 st ). The 48-hour work led to choice of four oils 64-hour analyses as shown by the blue highlighting and this work is now ongoing.

Results of the Task Group study and prior work on Matrix oils up to 48 hours:

When the results of the Task Group study are graphed, the matrix oils fall into two groups:

The PEI of these matrix oils could not be compared on the basis of one type of engine test and it was suggested that a ranking approach would show reasonable uniformity in ranking the oils. With the exception of the atypical FT-33 and the unknown precision of PEI(165-T), ranking of oils through the aging remained uniform.

A question of the agreement of two ICP methods of determining phosphorus content led to a small cooperative study:

Regarding the determination of phosphorus in the volatilized samples, statistical analysis showed very good agreement:

Chairman’s observations and recommendations: Observations : 1.The primary objectives of the Task Group have been met through due diligence over the last eight weeks. 2.A matrix of eight oils have been evaluated at extended test intervals of 32 and 48 hours. 3.It has been indicated by these tests that the present level of good correlation with different engine tests is not likely to be improved by extending the length time of the PEI(165) protocol. 4.For test precision and conservation of time and effort, it is preferable to run the shortest test that will provide an acceptable level of correlation.

Chairman’s observations and recommendations: Recommendations 1.That the work of the Task Group be continued in collecting the data from remaining 64- and repeat 48-hour tests. 2.That the present Task Group or a new group be charged with setting up and conducting a round robin using the PEI(165-16) protocol under the auspices of the ASTM Committee D02. 3.That the Task Group Chairman as present sponsor of the PEI(165-16) bench test provide a timeline chart for the ESCIT Chair within one week to meet the ESCIT Chair’s need.

Chairman’s personal observations on JAMA engine correlation data: 1.Correlation between bench test and engine test is almost always affected much more by the engine test repeatability than the bench test, which usually fairly repeatable. 2.The JAMA engine tests were run at 85° and 135°C while the PEI test is run at 165°C. 3.It is thus somewhat surprising that the correlations shown were in some cases as good as they were (ranging up to R² values of 0.56) considering the temperature dependence of ZDDP decomposition. 4.For meaningful comparison between PEI(165-16) and the JAMA oil #2, #4, and #5, higher temperature engine tests are needed. 5.Another interesting alternative would be to obtain data using the PEI protocol at 135°C. (PEI studies have been made and reported at temperatures of 120°C that have shown correlation with engine tests.)