© Chevron 2007 | Confidential - Chevron Oronite Companies Diesel Engines Showing Excellent Performance and Durability with Reduced TBN Lubricants and Low Sulfur Fuel Patrice Estoueig 3 rd International Conference 'Lubricants Russia 2007'. Moscow November, 29 th 2007

© Chevron 2007 | Confidential - Chevron Oronite Companies 2 The Changing Requirement for TBN TBN is a measure of a lubricant’s base reserve used for neutralizing acids Partly “strong base” which neutralizes acids very effectively Partly “weak base” which is less effective in neutralizing acids SAE shows detergent chemistry impacts Over the last 3 decades the nature of acidic contaminants has shifted Historically more strong acids (H 2 SO 4 ) from combustion of high sulfur fuel More acids and lower temperatures Drain periods TBN limited and not long enough to experience high oxidation Now mostly weak acids from oxidation of base oils Less acids as contaminants and vastly increased temperatures Longer drains resulting in more oxidative exposure

© Chevron 2007 | Confidential - Chevron Oronite Companies 3 The Introduction of Chemical Limits for Lubricants With ever more stringent emission legislation, OEMs introduced exhaust gas after-treatment devices These devices were anticipated to be sensitive to sulfated ash, sulfur, and phosphorus in fuels and lubricants Chemical restrictions were imposed Diesel fuel sulfur limited to a maximum of 15 mg/kg Diesel engine lubricants limited to Maximum 1.0 % sulfated ash (less detergent) Maximum 0.12 % phosphorus (less ZnDTP anti-wear) Maximum 0.4 % sulfur These chemical restrictions result in lower TBN lubricants

© Chevron 2007 | Confidential - Chevron Oronite Companies 4 A Field Test to Study Lubricant Degradation Objectives: Evaluate the impact of chemical restrictions on lubricant degradation Comparison of CI-4 Plus and CJ-4 type lubricants Evaluate the impact of lower sulfur diesel fuel on lubricant degradation Comparison of regular and ultra-low sulfur diesel fuel Field test description Test truck fleet doing Delivery Service Ten units total Five units on regular sulfur diesel fuel (RSD) Five units on ultra-low sulfur diesel fuel (ULSD) Flush-and-run type operation Drain interval nominally 25,000 miles with intermediate samples

© Chevron 2007 | Confidential - Chevron Oronite Companies 5 Test Oil Description CI-4 Plus Reference Prototype API CJ-4 Oil 1 Prototype API CJ-4 Oil 2 Prototype API CJ-4 Oil 3 Prototype API CJ-4 Oil 4 Field Test Color Code BlueRedYellowGreenBlack Fresh Oil TBN (D-2896) Detergent Type ABAB Anti-Oxidant Level LowHigh Low Phosphorus Level, wt%

© Chevron 2007 | Confidential - Chevron Oronite Companies 6 CJ-4 Oils Have Lower TBN Due to SAPS Limitations TBN D4739, mg KOH/g

© Chevron 2007 | Confidential - Chevron Oronite Companies 7 Used Oil Lead Shows No Correlation with Fresh Oil or Used Oil TBN

© Chevron 2007 | Confidential - Chevron Oronite Companies 8 TBN or TAN Based Used Oil Rejection Limits Do Not Apply to Modern Engines Using Low S Fuel and CJ-4 Oils

© Chevron 2007 | Confidential - Chevron Oronite Companies 9 Engines on Low S Fuel Showing Lower Used Oil Iron Content ; Less Wear ?

© Chevron 2007 | Confidential - Chevron Oronite Companies 10 Statistical Analysis Confirms the Significant Difference in Used Oil Iron

© Chevron 2007 | Confidential - Chevron Oronite Companies 11 Search for the Source of the Used Oil Fe Difference Engine inspections were performed on two of the units Both ran on the CI-4 Plus oil for the full duration of the field test One used ULSD, the other RSD Units had very similar mileage (165,000 and 170,000) Inspected parts Valve train Bearings Ring and liners

© Chevron 2007 | Confidential - Chevron Oronite Companies 12 No Difference in Valve Train Wear Between RSD and ULSD Units Crossheads from ULSD UnitCrossheads from RSD Unit

© Chevron 2007 | Confidential - Chevron Oronite Companies 13 No Obvious Difference in Bearing Wear Between RSD and ULSD Units Bearings from RSD UnitBearings from ULSD Unit

© Chevron 2007 | Confidential - Chevron Oronite Companies 14 ULSD Liner Shows Less Wear Anti-Thrust Side Indicator Liner Wear Step Polished Area below Top Ring Reversal Point Liner from ULSD UnitLiner from RSD Unit

© Chevron 2007 | Confidential - Chevron Oronite Companies 15 ULSD Unit Shows Consistently Lower Liner Wear

© Chevron 2007 | Confidential - Chevron Oronite Companies 16 Microscopic Images from RSD and ULSD Liners Show Difference in Wear Liner from ULSD UnitLiner from RSD Unit

© Chevron 2007 | Confidential - Chevron Oronite Companies 17 Liner Wear, with RSD, Has Corrosive Component : Crevice Corrosion – Crack Formation – Crack Propagation - Spalling Void from Removal of Cast Iron Exposed Graphite Flake Propagating Cracks Liner from RSD Unit

© Chevron 2007 | Confidential - Chevron Oronite Companies 18 Conclusions Properly formulated low TBN CJ-4 oils provide excellent engine performance TBN is not a clear indicator of fresh or used lubricant quality Chemical limits in CJ-4 allow for the formulation of diesel engine lubricants with performance equal to conventional CI- 4 Plus lubricants, thus maintaining backward compatibility Further reduction of sulfur and phosphorus levels could significantly impact lubricant performance to the point that backward compatibility can no longer be maintained Low sulfur diesel fuel reduces acid formation in the power cylinder and improves the durability of diesel engines