1 Afton ESCIT Report An Analysis of Sequence IIIG Reference Oil Data Phosphorus Retention - and Volatile Phosphorus Throughput December 12, 2006

2 Overview We have reviewed all available Reference oil Sequence IIIG data as they relate to phosphorus Sequence IIIG used oils have been analyzed for: –Percent phosphorus retention –Total phosphorus throughput –Volatile phosphorus throughput

3 Both elements concentrate in used IIIG oil but Ca concentrates to a greater degree due to base stock volatility and thus it can be used as a marker for volatile oil consumption. Phos Retention Primer

4 Calculation of Phos Retention Initial P conc. is adjusted for increase in Ca at T % decrease is Retention PR% = (CaInit/CaEOT) * (PEOT/PInit) * 100

5 TMC Reference Oil Data Three reference oils –TMC 434, SAE 5W-30, 0.08 P –TMC 435, SAE 5W-20, 0.08 P –TMC 438, SAE 5W-20, 0.10 P Data submitted by four labs –Afton, Mobil, Intertek, SwRI 120 total observations, nearly evenly divided among the reference oils

6 Range of results is between 72 and 90% across all reference oils. This wide range is influenced by the differing performance of the oils.

7 The range of results for a given reference oil is about 10 – 12 %. The overlap of the distributions means a single test point on any oil could fall within any distribution with equal statistical probability.

8 Strengths and Weakness of PPR Strengths: –Easy to calculate –Can be applied to any used oil from any test Weakness: –Gives no information about actual phosphorus throughput (mass) –Has not been correlated to catalyst poisoning –Assumes that all of the missing phosphorus was evacuated from the engine as volatile vapor What about the phosphorus that is incorporated into the anti-wear layer protecting engine parts?

9 Volatile Phosphorus Consumption Proposed ESCIT calculation can cause very misleading conclusions. Almost 30% of tests produce an INCREASE in calcium MASS at 20-hours of Sequence IIIG testing This results in a NEGATIVE value for phosphorus consumption – or the creation of matter In this analysis we treat all negative values as zero, but they should probably be thrown out

10 ESCIT Calculation of Phosphorus Throughput (Total, Volatile and Liquid) ESCIT-proposed calculation method with Afton modification Calculated using the Initial, 20, 40, 60, 80, and 100-hour oil level measurements along with used oil elemental analyses Step 1: Determine the mass of oil –This is performed by using the oil level measurement information from the test lab –This information is used to determine total oil consumption Step 2: Determine the mass of each element present in the oil –This is performed before and after the oil level step using the data from Step 1 and the ICP elemental information –Mass of Ca and mass of P present in the oil are calculated Step 3: Determine the loss of calcium (mass) –Subtract the mass at current test Interval from the previous test interval –This is later related to BULK or LIQUID oil consumption and used to determine volatile P cons. –WARNING: THIS CAN SOMETIMES BE A NEGATIVE NUMBER DUE TO ERRORS Step 4: Determine the amount of oil consumption due to bulk (liquid) oil consumption –Uses average Ca concentration during test interval to calculate oil mass, then this computed value for liquid oil consumption is subtracted from measured value for oil consumption –Since this is bulk or liquid oil consumption, the mass of phosphorus can be calculated. –WARNING: THIS CAN SOMETIMES BE A NEGATIVE NUMBER DUE TO ERRORS Step 5: Determine the amount of oil consumption and P depletion due to volatile losses. –By difference of Step 4 from –WARNING: THIS CAN SOMETIMES BE A NEGATIVE NUMBER DUE TO ERRORS Step 6: Sum the mass of volatile phosphorus consumption across all 5 test intervals. –Afton treats all negative values as zero.

11 Errors in the measurement ICP-MS for elemental concentrations –Stated repeatability of the method is about +/- 30 ppm at measured levels of P and Ca The reference oils show a 100 ppm standard deviation for the initial oil sample Sequence IIIG Oil Level –Accurate to 3 mm on the dipstick –This translates to about ml –Since the amount “low” is the difference between the current and prior oil level the error can be multiplied –Problematic for low-volatility oils and any oil with low oil consumption

12 The range of results for all oils is quite broad. Breaking the distribution up into individual reference oils makes sense.

13 The distributions are still quite large and overlap. Looking at the actual grams might increase separation.

14 Separation is increased but the distributions still overlap. Test precision is quite poor for this parameter and a single point could fall within any distribution with equal statistical probability.

15 Statistical Comparison of TMC Data This table shows the overlap of population confidence intervals. There is much overlap of the intervals. Remember: A significant number of tests (~30%) were assigned a zero value for volatile Phos consumption.

16 Afton’s Position on the Seq. IIIG for Emission System Compatibility We need a performance test to ensure the compatibility of engine oils with emission control systems to replace chemical limits. We need a test with better power to discriminate than the Sequence IIIG. As of today, the IIIG test appears unable to reliably measure and discriminate phosphorus volatility or phosphorus throughput We are concerned that a bad test will bounce oils, not result in a material improvement in catalyst compatibility, or place artificial limits on durability. –We could potentially sacrifice deposit and/or wear protection for phosphorus retention and still not improve catalyst compatibility ESCIT needs to continue the search for a reliable and precise method to ensure improved catalyst compatibility