Extending the Life of Engine Oils: Opportunities and Challenges

1. Extending the Life of Engine Oils: Opportunities and Challenges

2. Introduction: Contributors • R&D - Fluid Chemistry & Systems • Dan Blossfeld • Changsoo Kim • Jim Linden • R&D - Experimental Test • Ed Klusendorf • Tim Festian • Jim LaMothe • Joe Meerschaert • R&D - Other • Ion Halalay • Mike Rogers • R&D - Milford Operations • Gus Mitsopoulos • Scott Baize • Dave Coleman • Jerome Kowalski • Vance McCabe • GM Powertrain • Bob Olree • Matt Snider • Jill Cummings • Dave Staley • Tom Spix • GMNA Product Development • Pat Hanley • Kim Bennett • Paul Harvath • Jessica Kelsch • Craig O’Brian ISFL-2008 – “Extending the Life of Engine Oils”

3. Introduction: Drivers • Customer demand • Reduce maintenance • Convenience • Cost savings • Environmental benefits • Reduce used oil handling and disposal • Conserve petroleum resources • Increased warranty protection • Avoid uncertainty of service-fill oil quality • Competitive advantage • Maintain GM’s leadership position without compromising engine durability ISFL-2008 – “Extending the Life of Engine Oils”

4. Introduction: Where are we now? The GM Engine Oil Life System (EOLS) • Fundamental factors that influence oil life: • Primary Factor: COMBUSTION EVENT • Exposure to the flame front on the cylinder wall destroys oil and additives • Combustion products such as acids and reactive radicals in the blow-by contaminate and react with oil • Secondary Factor: OIL TEMPERATURE • Increased temperature increases oxidation rate of oil • Decreased temperature increases concentration of water and fuel in the oil • Mileage is not a fundamental factor affecting oil life ISFL-2008 – “Extending the Life of Engine Oils”

5. Basics of the Oil Life System: How It Works ISFL-2008 – “Extending the Life of Engine Oils”

6. EOLSHistory >30,000,000 Vehicles 1983 Testing 1988 Introduction 2003 Coverage 2004 Maintenance I / II 2005 Milestone ISFL-2008 – “Extending the Life of Engine Oils”

7. 2006 Model Year EOLS Statistics • The sales-weighted average oil drain interval for 2006 model year GM vehicles equipped with Engine Oil Life Systems is 8,500 miles • The typical oil drain interval specified by GM competitors is 5,000 miles • Results for 2006 model year GM vehicles: • The EOLS will save an estimated 6,600,000 gallons of oil annually for 2005 model year vehicles • The EOLS will save 2005 model year GM customers an estimated $150M annually due to fewer oil changes. Assumptions: 1) 15,000 miles driven per year, 2) 5.5qts of oil per vehicle, 3) 8,500 mile avg oil drain interval for EOLS, 4) 5,000 mile avg oil drain interval for non EOLS, 5) $30 per oil change, 6) 3.9 million vehicles built with EOLS in 2006, 6) All customers who have the EOLS available to them use it. ISFL-2008 – “Extending the Life of Engine Oils”

8. Introduction: Where is GM going? • Short Term / Continuous Improvement • Increase oil change intervals through the GM-developed Engine Oil Life System as service oil quality improves and the understanding of oil degradation processes increases • Mid Term • Employ relatively simple hardware modifications with advanced commercial lubricant formulations to make a significant step in oil drain interval capability • Long Term • Develop new lubricant formulation strategies and incorporate new engine hardware technology, including an oil condition sensor, to permit greatly extended oil change intervals ISFL-2008 – “Extending the Life of Engine Oils”

9. Introduction: How are we getting there? • Engine Dynamometer Testing as a Development Tool • Understanding modes of engine oil deterioration • Rapid evaluation of new lubricants and hardware • Maintain precise control of operating conditions • Vehicle Demonstration Tests • Validate performance seen in dynamometer tests • Employ a wide variety of driving conditions • Advanced Research on Extending Engine Oil Life • Continuous additive replenishment • Real time oil quality sensors ISFL-2008 – “Extending the Life of Engine Oils”

10. Engine Dynamometer Testing: • Different driving conditions have different effects on oil deterioration: need to make choices on screening tests ISFL-2008 – “Extending the Life of Engine Oils”

11. GF-4 High-temperature; high-load test • Test Engine and Operating Conditions • GM 3.4-L 60º V6 SI w/ oil cooler ISFL-2008 – “Extending the Life of Engine Oils”

12. High-temperature; high-load test • Oil Analysis Example: Kinematic Viscosity at 40 and 100 ºC • Corrections made for oil consumption (measured in real time) ISFL-2008 – “Extending the Life of Engine Oils”

13. High-temperature; high-load test • Performance Factor • All individual oil properties that change during HTHL-EDT tests play a role in determining oil performance • Simplest approach is to weight all factors equally • A composite Performance Factor (PF) can be calculated relative to the baseline condition for measuring the effect of a: • Specified lubricant • Given set of hardware conditions • Given set of operating conditions ISFL-2008 – “Extending the Life of Engine Oils”

14. High-temperature; high-load test • Significant potential improvements in oil life with a variety of advanced oil formulations • Performance Factor Results ISFL-2008 – “Extending the Life of Engine Oils”

15. High-temperature; high-load test • Useful for determining Engine Oil Life System parameters • Useful for determining effects of hardware changes • Effect of Operating Parameters on Oil Degradation ISFL-2008 – “Extending the Life of Engine Oils”

16. High-temperature; high-load test: • The most critical question: • How long can a lubricant perform before experiencing significant degradation in performance and/or engine damage? • Problem: most modern lubricants are stable enough to perform adequately until oil addition is required. • The HTHL test does not “break” GF-3 oils during the 125-h test • Solution: Run a 2x (250 h) HTHL test by adding used oil from a prior identical run after the first 125 h to refill the sump ISFL-2008 – “Extending the Life of Engine Oils”

17. High-temperature; high-load test:Failure Point of a GF-3 Oil • “Break” in oxidation, kinematic viscosity, TAN, PIN and Pb corrosion • GF-3 failure point is about 215 h ISFL-2008 – “Extending the Life of Engine Oils”

18. Short Trip & Sludge Dynamometer Tests • Capability for Determining effects of fuel and water contamination on performance and deposits • Substantial fuel and water buildup (>25%) can be observed during one winter of short-trip driving conditions • Potential for cold-temperature sludge formation due to cycles of cold / warm temperature operation ISFL-2008 – “Extending the Life of Engine Oils”

19. Engine Wear Dynamometer Tests • Real-time radiotracer wear measurements • Piston rings: bulk neutron activation • Cylinder bore: surface layer activation ISFL-2008 – “Extending the Life of Engine Oils”

20. Lead Shield Detector Oil Chamber Dewar Oil from sump Engine Wear Dynamometer Tests • Wear Measurement Hardware: ISFL-2008 – “Extending the Life of Engine Oils”

21. Engine Wear Dynamometer Tests • Piston ring wear data during steady-state wear map ISFL-2008 – “Extending the Life of Engine Oils”

22. Engine Wear Dynamometer Tests • Effect of Severely Aged Engine-Aged Oil on Ring Wear 16,000 miles of a city driving schedule • No degradation seen in ring wear performance with severely degraded oil ISFL-2008 – “Extending the Life of Engine Oils”

23. Vehicle Demonstration Programs • Different driving conditions have different effects on oil deterioration: need to validate that there are no “surprises” under more common driving conditions ISFL-2008 – “Extending the Life of Engine Oils”

24. Vehicle Demonstration Programs • Major step-out improvements are achievable in oil drain intervals with appropriate oil quality and hardware technology ISFL-2008 – “Extending the Life of Engine Oils”

25. Advanced Research on Extending Engine Oil Life • Hardware • Periodic replenishment of specific oil additives • Real-time oil quality measurements • Major changes in engine hardware configurations (hybrid, SIDI, etc.) • New Classes of Lubricants • Base stocks and additives • Fuel Effects • Oil Deterioration Tribology; Modeling ISFL-2008 – “Extending the Life of Engine Oils”

26. Advanced Research on Extending Engine Oil Life • Periodic replenishment of specific oil additives • Oil oxidation proceeds rapidly at sump temperature increases • Antioxidants can be added at a rate matching the depletion rate ISFL-2008 – “Extending the Life of Engine Oils”

27. Advanced Research on Extending Engine Oil Life • Real-time measurement of oil quality • Low cost is a requirement • Fail-safe backup to the EOLS algorithm • More critical to measure as oil life increases • Protects against low quality service fill oil • Protects against unforeseen circumstances • Many sensor options are promising ISFL-2008 – “Extending the Life of Engine Oils”

28. Real-time measurement of oil quality • a.c. impedence spectroscopy is used to measure fundamental properties as the oil ages ISFL-2008 – “Extending the Life of Engine Oils”

29. Conclusions • Extending the vehicle’s oil change interval has significant benefits, both for the consumer and for the environment • Engine dynamometer tests play a critical role in extending oil life: • High temperature tests simulate oxidation failure modes • Low temperature tests simulate fuel and water contamination modes • Real-time wear measurements assure long-term engine durability ISFL-2008 – “Extending the Life of Engine Oils”

30. Conclusions (cont’d) • Vehicle demonstration tests are important to: • Validate predicted performance • Test a wider range of operating conditions • Advanced research is needed to reach greatly extended oil life. Promising enabling technologies include: • Continuous additive replenishment • Real-time oil quality sensors • New classes of base stocks and oil additives ISFL-2008 – “Extending the Life of Engine Oils”

31. Thank you. ISFL-2008 – “Extending the Life of Engine Oils”