As 2014 drew to a close, the ticklish issue of how to label the coming heavy-duty engine oil upgrade came squarely to the foreground. This upgrade, known for now as PC-11, will need two distinct names under the American Petroleum Institutes licensing system. One could follow the familiar API C series, but the other version must be flagged clearly for consumers as a fuel-economy specification for the latest-model engines – not for existing and older heavy-duty diesels.
The New Category Development Team creating the heavy-duty upgrade convened in San Diego on Dec. 9, during the ASTM Committee D2 meeting. Chaired by Dan Arcy of Shell, it includes representatives from API, the Truck and Engine Manufacturers Association (EMA), and the American Chemistry Council, which represents additive companies.
In San Diego, the NCDT was reminded that prior categories posed less difficulty since their viscosity grades were in alignment with traditional SAE J300 viscosity limits. However, PC-11 presents a fresh dilemma since it will be two categories in one. PC-11A will be the normal engine oil, totally backwards compatible with earlier API categories. This version is likely to be called API CK-4, succeeding the current API CJ-4 category.
Its cousin PC-11B will have a lower high-temperature, high-shear rate (HTHS) viscosity to offer some improvement in fuel economy. However, there is likelihood that it may not be fully backwards compatible as preferred under APIs Engine Oil Licensing and Certification System. So PC-11B oils cannot simply take up the next letter in the API C sequence.
The naming issue has been discussed for over a year, with several proposals for differentiating the two oil subcategories. One early idea came from EMA, the Truck and Engine Manufacturers Association, which asked that each version have improvements in oxidation stability, aeration and shear stability. The core difference between the subcategories is their HTHS limit.
For SAE 10W-30 grade oils, HTHS viscosity will be set at a minimum 3.5 centiPoise for PC-11A, and at a lighter 2.9 to 3.2 cP for PC-11B. The oil industry has expressed concern that there is insufficient difference – just 0.3 cP – between the PC-11A and PC-11B HTHS specifications to allow for a reasonable blending tolerance when making the finished oils. Retailers have also voiced concern over having two versions of the same viscosity grade on their shelves.
Although SAE 10W-30 represents a small percent of North Americas heavy-duty engine oil sales today (about 6 percent, according to the additive company Infineum USA), sales are accelerating as more engine manufacturers recommend this grade to capture fuel economy benefits.
EMA noted that ACEA (which writes oil specs for European vehicles) was setting the HTHS limit for XW-30 multigrade oils at 3.2 cP to assure fuel economy. There are no general data supporting this viscosity; however, Volvo Powertrain has data demonstrating a benefit, and has incorporated 3.2 cP HTHS into its own Volvo engine oil specification.
The New Category Development Team had requested guidance from the API Lubricants Group for naming the two sub-categories. The Lubricants Group responded that for the high HTHS version (PC-11A), it was comfortable with the category name API CK-4. For the low HTHS version (PC-11B), the discussion centered on how to establish an evergreen aspect for future categories.
Oil marketers also want to see a minimum number of characters that must be displayed, and to see a distinct difference between PC-11A High Vis and PC-11B Low Vis. Theyd prefer an evergreen name or symbol, and that the low-viscosity oil not sound like the high-vis oil.
After testing several naming options within the NCDT, agreement was reached on the following system: PC-11A oils should be designated as API CK-4, while PC-11B oils would be designated as API FA-4.
In addition, an H or L would be added to the SAE XW-30 viscosity grade to clearly differentiate the fuel economy (L) and non-fuel economy (H) sub-grades. At left are proposed API service symbols demonstrating how the marks would look.
Next, on Dec. 20, Dan Arcy presented the question of having SAE XW-30 in both H and L versions to an SAE J300 Engine Oil Viscosity Classification Task Force, to weigh its concurrence with the concept. The J300 Task Force responded that it was acceptable – provided it garners broad market support. SAE also must vote to modify its J300 standard to incorporate the L and H definitions.
The designations are not chiseled in stone, so dont order new labels to be printed up yet! There are many steps to go before marketers can begin to strategize for their CK-4 and FA-4 product launches, as API engine oil manager Kevin Ferrick reminded LubesnGreases last month. First, APIs heavy-duty subcommittee was to discuss the issue on Jan. 28. A Standards meeting then would have to convene to review it, perhaps this month or next. And the proposed designations still must be considered, balloted and approved by the full Lubricants Group.
EMA still wants to see these heavy-duty oils begin licensing before the end of 2016. Ferrick acknowledged that the PC-11 clock is ticking down – and the pressure is on for API to take each step at a full run. z
Steve Swedberg is LubesnGreases automotive editor. Tom Glenn is away; look for his Need to Know column to return next month.