1 Proposal for Phosphorus Emission Index Inclusion in GF-5 ESCIT Meeting April 24, 2007 Presented by: Ted Selby Savant, Inc.

2 Engine Oil Phosphorus Emission Control in GF-5  Phosphorus emissions from engine oils have been clearly shown by Phosphorus Emission Index (PEI) studies to be independent of either the volatility of the engine oil or the initial phosphorus level reflecting the ZDDP in the oil. Considerations  Extensive studies have now demonstrated that engine oil phosphorus emissions are dependent on the chemistry of the ZDDP and, perhaps, other additives in the engine oil.  In particular, limiting phosphorus volatility on the basis of initial phosphorus level in the engine oil – although seemingly intuitive – is counter-productive and should be questioned.  This was shown in recent PEI studies at 165°C of a series of ILSAC GF-4 and API SM engine oils in which small variation of initial phosphorus values around 800 PPM gave no clue to the actual phosphorus volatility ranging from 250 to 1450 PPM …..

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4 Engine Oil Phosphorus Emission Control in GF-5  Reasonably repeatable engine tests are absolutely essential in proving the need for appropriate levels of lubrication and in the process should generate reference oils for correlation. Considerations  However, placing engine tests in specifications of engine oil acceptability must be carefully weighed as to their costs of maintenance and the logistics of parts and fuels as well as the costs of tests and re-tests with modern engines and oils.  Moreover, the increasingly rapid rate of engine design and redesign has led to multiplicity of engine test sequences.  As our understanding of the engine grows, a better path may be that bench tests correlating with field results and/or pertinent engine test protocols should be encouraged, generated, and applied in engine oil specifications.

5 Considerations regarding bench tests Bench tests have much to offer: 1. Markedly less complicated, normally. 2. Usually much more repeatable. 3. Free from need to stock parts and accessories for long periods. 4. Modifiable to keep pace with engine needs and redesign. 5. Much lower costs for equipment, facilities, and tests. 6. Usually show greater reproducibility among laboratories. 7. Often can produce clearer insight on the desired physical or chemical parameter since the data sought can be either isolated from, or incorporated with, other engine variables. Engine Oil Phosphorus Emission Control in GF-5 8. Permits formulations to be screened and modified quickly.

6 However, the critical words for an acceptable bench test are “engine-correlated” and “well-designed”. The engine/bench test relationship The engine is always the source of the relevant test information and the critically important test lubricants. With essential engine information and oils, developing a bench test then requires reasonable understanding and insights into both physical and chemical factors involved in engine operation and innovative ways of applying these to instrument design. When successfully developed, bench tests have often led the way to understanding engine parameters and interactions not quite clear because of complicating engine operating factors. Engine Oil Phosphorus Emission Control in GF-5

7 The PEI is a simple approach to determining phosphorus volatility and has good repeatability. Good correlation has been shown to the ESCIT with taxi fleet tests – an overall correlation of R²=0.82. PEI/engine correlation Chevron Oronite also reported good correlation between PEI(165-16) values and Sequence IIIG results in previous ESCIT meetings. Engine Oil Phosphorus Emission Control in GF-5

8 Inclusion of PEI in the GF-5 specification Engine Oil Phosphorus Emission Control in GF-5  On the basis of the previously shown plot of initial phosphorus concentration versus volatility, a PEI value of 50 was equivalent to ~800 PPM.

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10  It is suggested that a PEI value of 50 be set as an upper GF-5 limit for phosphorus volatility using the 165°C/16 hours protocol. Inclusion of PEI in the GF-5 specification  The value of ~50 also corresponds to the PEI value shown for the Ford-Lubrizol Low Impact oil at 165°C as well as for the TMC IIIG Reference Oil 435. Engine Oil Phosphorus Emission Control in GF-5  On the basis of the previously shown plot of initial phosphorus concentration versus volatility, a PEI value of 50 was equivalent to ~800 PPM.  It is further suggested that 1) initial phosphorus level be only reported, and 2) consideration be given to relieving, to some degree, present engine oil volatility constraints.