The next heavy-duty engine oil upgrade, known as PC-11, took center stage June 26 during ASTM Committee D-2’s technical week in San Francisco. The New Category Development Team (NCDT) is making progress in creating the oil that will be needed for heavy-duty diesels produced starting in 2016.
The NCDT is actually developing two oils. The first is a fully backwards-compatible product with traditional viscometrics, such as SAE 15W-40. The second will be a lower-viscosity oil providing fuel economy benefits. Whether the lower-vis version will be fully compatible with current and older on-road equipment has not been determined yet.
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The team’s chairman, Dan Arcy, global OEM technical manager for Shell Global Solutions, noted that the meeting was packed both from an agenda standpoint as well as in attendance, with more than an estimated 100 in the audience.
The meeting heard that, in general, the effort to produce a new oil category is on schedule for a 2016 introduction However, the American Chemistry Council, which represents lubricant additive manufacturers, requested a delay of six months from January to July of 2016. This would accommodate the development work needed for the new passenger car engine oil upgrade (ILSAC GF-6) which is also scheduled for a January 2016 debut.
ACC reasoned that bringing two new categories to market at the same time will result in huge bottlenecks in engine test development, matrix testing, and early blending and testing programs for product approvals. This will be discussed with the American Petroleum Institute’s Lubricants Group, which will license all the new oils.
The NCDT meeting also reviewed three new engine sequence tests which have been identified for PC-11.
The first, the Caterpillar C-13 engine oil aeration test, is moving ahead with a projected end-of-2012 timing for finalizing the test procedure. If work continues as projected, matrix testing can begin early next year. This test procedure seems to be on or slightly ahead of schedule.
Second is a scuffing-wear test being developed jointly by Detroit Diesel and Lubrizol. The NCDT heard that this test is currently operating and has six test runs under its belt. Conditions for the procedure include a 100-hour test with oil sampling every 20 hours, and end-of-test rating of engine parts. A preliminary selection for a “poor” reference oil (2.9 cPs high-temperature, high-shear viscosity) has been made. The final HTHS viscosity for the PC-11 fuel-economy formulations hasn’t been set as yet, but minimum targets from 2.9 to 3.2 cPs are being mentioned.
Third is the Mack T-13 test, which is under development and apparently on time as well. This test, a replacement for the T-12 test, will measure engine ring and liner wear, lead levels at each oil change and end of test, and oil consumption.
As well, there’s a possibility that the T-13 may be used as an oxidation test. However, Caterpillar has suggested an oxidation test based on its 1Y-3700 SCOTE engine (currently used in the Cat 1P test). Proposed test conditions and other details have not been released yet.
The desire for a new oxidation test comes from concerns that the Sequence IIIG (the oxidation test for today’s API CJ-4 heavy-duty oils) is due to be replaced by a new sequence test for GF-6. However, that test hasn’t been defined yet, so there is a possibility that PC-11 could be without an oxidation test. Heavy-duty engine manufacturers, represented by the Truck & Engine Manufacturers Association (EMA) are still looking for possible replacements for the Sequence IIIG.
The NCDT’s Shear Stability Task Force reported that they are collecting field samples of diesel oils to determine if viscosity shear down could be a problem. In the past, soot loading-which tends to thicken oil-has partially masked the effects shearing has on viscosity index improvers. However, with the introduction of selective catalytic reduction (SCR) systems on more trucks, oils seem to be running cleaner. So the task force is rethinking what the limit should be for viscosity loss in sheared oils.
The NCDT meeting spent some time discussing category language and how to designate the new oils. This is an issue for the industry since the new oil category will come to market as two oils (traditional and lower viscosity, as described above). Three options emerged to deal with this situation:
1. API could identify the traditional oil as API CJ-4+ (signaling compatibility with today’s CJ-4 oils) and the lower-viscosity oil as CK-4.
2. Have two completely new categories. CK-4 would be for the traditional oil and CL-4 for the lower viscosity oil.
3. Go forward with CK-4 for the traditional oil and a completely different category designation for the lower-viscosity products. An example might be LV3.0 meaning lower viscosity with 3.0 cPs HTHSV.
Options 2 and 3 seemed to gain the most traction with the attendees.
The NCDT meets next in early August in Baltimore.