COS Blog

PC-11 Gets Green Light

By Steve Swedberg • December 16, 2015

AUSTIN, Texas – PC-11, the next heavy-duty engine oil upgrade, received the go-ahead from both ASTM and the American Petroleum Institute here last week. The new category – which API officially will call CK-4 along with its fuel economy version, FA-4 – now is assured of being available for licensing on Dec. 1, 2016.

Products meeting API CK-4 will continue to be backwards compatible with earlier categories, such as CJ-4 and CI-4PLUS. However, API FA-4 may have only limited backwards compatibility due to the fact that its minimum high-temperature, high-shear viscosity falls below that specified in prior category requirements.

The PC-11 approvals came in a flurry of meetings on Dec. 8, 9 and 10 during the half-yearly gathering of ASTM Committee D02 on Petroleum Products and Lubricants. First, ASTM’s Heavy Duty Engine Oil Classification Panel, chaired by Shawn Whitacre of Chevron, had to review and accept all of PC-11’s tests and limits, which it did Dec. 8.

Immediately following, two other stakeholder groups chimed their agreement: the Diesel Engine Oil Advisory Panel, which represents engine builders and oil and additive companies and is jointly chaired by Steve Kennedy of ExxonMobil and Greg Shank of Volvo Powertrain; and the New Category Development Team, led by Dan Arcy of Shell, which began working on PC-11 back in December 2011 and adroitly steered it to completion.

On Dec. 9, ASTM D02 Technical Committee B moved to ballot the new standard, a simple formality now that all hurdles have been cleared. Joe Franklin of Intertek is this committee’s chairman.

That left API’s Lubricants Group, chaired by Scott Lindholm of Shell, to write PC-11 into Document 1509, which governs the institute’s engine oil licensing system. Thanks to the group’s unanimous vote on Dec. 10, oil marketers can now lay plans to roll out CK-4 and FA-4 products next Dec. 1. That will be the first date licensees may display these designations in the trademarked API “donut” on their labels.

There are still several issues API will need to clean up in the coming months. First, the VGRA-BOI work is ongoing, with matrix testing unfinished yet.

VGRA, viscosity grade read-across, is allowed under API 1509 as a means of reducing engine sequence test costs, by comparing certain engine test results across multiple viscosity grades. Often, for example, lower viscosity oils have more difficulty in successfully passing certain procedures; if an SAE 10W-30 oil earns a passing grade, its results can be read across to a heavier grade such as SAE 15W-40, eliminating the need to run additional tests.

The same holds true for BOI, or base oil interchange. API has grouped base oils according to specific properties, such as sulfur content, saturates content and viscosity index. If a company with an approved engine oil formulation wants to change base oils, BOI guidelines may allow the blender to replace at least some of the original base oil without entirely re-testing the formulation.

So far, enough supporting data has been generated to establish BOI between Group II base oils for PC-11, but not for switching between Group II and Group III, nor for switching within the pool of Group III base oils.

Another and more provocative issue is how marketers will label the new oils – CK-4 and FA-4 – and how they’ll communicate the differences effectively to end users.

API commissioned a study to determine what users value and believe to be descriptive of oil performance. The first results from this study showed that brand name and viscosity grade are the only information that participants consistently said they recognize! The API donut trademark and other terminology are mysteries to most users.

Given that, API has decided to develop an educational piece to communicate the benefits of engine oils with API category designations, which will include information about the importance of viscosity grade and its impact on fuel economy.

During the PC-11 development process, several ideas were tested and discarded regarding public awareness efforts. One proposal was to create an exotic viscosity grade, “SAE 26,” which presumably would identify heavy duty engine oils meeting the FA-4 definition for the SAE XW-30 grade, which has a high-temperature, high-shear viscosity limit of 2.9 to 3.2 centiPoise.

However, there is also room in CK-4 for an SAE XW-30 with HTHS of 3.5 minimum cP. It’s recognized that this could create confusion for oil customers trying to select the correct product.

Another idea put forth was to label the viscosity grade as “SAE XW-30 L” or “SAE XW-30 H.” This was deemed just as confusing as the SAE 26 concept. In the end, the viscosity identification system was left unchanged.