Talking PC-11 engine oils with Chevron oil veteran

SAN RAMON, Calif. — Chevron’s Shawn Whitacre has been named chairman of the ASTM’s (American Society for Testing and Materials) Heavy-Duty Engine Oil Classification Panel.

Whitacre was chosen for the position after the retirement of long-time Chevron veteran Jim McGeehan, who previously served in that capacity.

As chair, Whitacre, who is senior staff engineer, technology for Chevron, is charged with heading the committee that will establish ASTM standards for the looming PC-11 heavy-duty engine oil category.

“We’ve worked for many years to piece together this new standard, which is happening under the umbrella of the PC-11 new category development,” Whitacre said in an interview with “In my role as chairperson, it’s important that I make sure that all member voices are heard. I help negotiate consensus. The real important thing is to be very transparent as we go through this process.”

We caught up with Whitacre to discuss his new role, and also the impending arrival of the new PC-11 heavy-duty engine oil category and its implications for fleets. In one of the most recent developments, the rollout date for PC-11 has been moved forward to December 2016 from its original launch date in early 2017.

“We’re now committed to a December 2016 first license date,” Whitacre confirmed. “That’s the first time in which oil marketers can officially utilize the category and the nomenclature inside the API donut. It won’t be until December 2016 that we can start claiming the new category, which will be called either CK-4 or FA-4, depending on the viscosity grade of the product.”

Unlike previous HDEO categories, PC-11 will consist of two sub-categories: CK-4 will be a straight replacement for today’s CJ-4 oils and the FA-4 category oils will be of a thinner viscosity, optimized for fuel economy.

While the rollout date for the new category may seem distant, the specification must be fully approved a year in advance of the first licensing. That means December 2015 is the real deadline for standards to be developed and for the category to be finalized.

“That’s why this next four months is going to be very busy as we get all these pieces wrapped up and get the official votes that authorize this as an ASTM spec’,” Whitacre explained.

Asked if there’s anxiety among oil companies to meet the looming deadline, Whitacre said “It’s aggressive, but I think we’ve got a reasonable handle on it. We’re certainly working under tight deadlines, but that’s nothing new for (HDEO) category development.”

One of the biggest questions involving the PC-11 oil category is whether or not both sub-categories will be backwards compatible with previous-generation engines. The thinking initially was that only the CK-4 oils would work on existing engines, which would require companies that want to take advantage of the fuel-saving potential of FA-4 oils to stock both types: CK-4 for their older engines and FA-4 for new additions to their fleet.

Whitacre said it’s still too soon to determine whether some engine OEMs will allow limited compatibility of FA-4 oils in older engines.

“There are a couple elements to the backwards compatibility question,” Whitacre explained. “One is, on paper, the new low-viscosity (FA-4) sub-category won’t officially be backwards compatible in terms of the specification because it defines the viscosity range that’s mutually exclusive from older categories. There’s a viscosity measurement called high temperature, high shear viscosity, or HTHS. Prior categories require that viscosity to be 3.5 centipoise; this new low viscosity category will require that products be somewhere between 2.9 and 3.2 centipoise. Because of that, products meeting FA-4 will not be able to claim those older categories, which require a higher viscosity. From that standpoint, they’re not backwards compatible.”

But – and it’s a big but – Whitacre said some engine OEMs could choose to allow FA-4 oils in their existing engines.

“I’d say the jury is still out on that part of the question,” Whitacre said. “I think the OEMs are working hard to better understand to what extent they’ll be allowed to offer that flexibility.”

The fuel economy gains achieved by FA-4 could be substantial. Whitacre said Chevron is seeing improvements of up to 5% compared to 15W-40 engine oils in laboratory testing, but he acknowledged it’s likely to be more in the range of 2% in real-world applications.

Asked if PC-11 will spell the beginning of the end for 15W-40 engine oils as the predominant viscosity grade, Whitacre said, “I don’t think the category itself will put an end to it. (15W-40) still represents a pretty sizeable fraction of the market today.”

Whitacre said fleet managers should be initiating discussions today with their oil suppliers and OEMs to see how the new engine oil category will fit into their operations.

“They ought to be talking with their oil suppliers and talking with their engine OEMs about the options available to them, being clear about what their preferences are and their constraints and what makes the most sense for their operation,” Whitacre said. “Different fleets have different needs in terms of what they want to run their business and where their priorities are, whether it’s maximizing fuel economy or trying to achieve long drain intervals, or maybe even commonality with other products in their fleet. It’s not at all too early (to be discussing PC-11). In fact, now is the right time to be getting prepared for changes that will start coming to the market late next year.”

The new oil is something fleets should look forward to, he added. In addition to providing the opportunity to improve fuel economy, the new category will also offer improved oxidation stability and maybe even longer drain intervals. Of course, the cost of developing a new standard will have to be borne by the market, but Whitacre said it’s too early to anticipate any price increases.

“I think it’s probably too early to tell to what extent these performance upgrades will drive changes to price,” he said. “We’re very conscious of making sure that what we sell to our customers makes sense to their bottom line.”


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James Menzies is editor of Today's Trucking. He has been covering the Canadian trucking industry for more than 20 years and holds a CDL. Reach him at or follow him on Twitter at @JamesMenzies.

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