Q&A: Chevron Chief Engineer Shawn Whitacre on Heavy-Duty Engine Oil Trends

Chevron Lubricants recently announced that it was “simplifying” its heavy-duty engine oil lineup. Part of this new product alignment is a new emphasis on synthetic oil blends, which have been gaining in popularity among fleets in recent years.

Shawn Whitacre, principal engineer on heavy-duty engine oil trends for Chevron Lubricants, talked with HDT about recent changes Chevron has made, why synthetics are so popular, and what a new oil category will mean for North American fleets.

HDT: Chevron recently announced plans to “simplify” its heavy-duty oil product line. Can you elaborate?

Whitacre: It really dates back to the challenges we’ve had over the past few years. Our customers count on our products to power their business. We’d had supply chain issues, which were out of our control. But they really strained our abilities to meet our customers’ needs.

These challenges presented us with an opportunity to take a step back and rethink our product strategy. The last time we’d revamped our product offerings was back in 2016 when the then-new CK-4 standards came out. Our strategy then was to offer a robust product mix to meet a broad range of customer needs. And, to a large extent, that means offering a full spectrum of viscosity grades.

HDT: And you had your ultra-low-ash technology oils come out in 2017?

Whitacre: Yes. That introduction, along with the introduction of other niche products, prompted a sort of ballooning of our product portfolio. And the feedback we were getting from fleets was that it was all too complex. So we needed to simplify.

But, at the same time, we were seeing an increase in demand for synthetic oil blends. So, we’ve made a deliberate effort to simplify our product range. And doing so will allow us to streamline our supply chain issues and offer better prices to our customers.

HDT: What are some of the trends in heavy-duty engine oils that fleets should be keeping an eye on?

Whitacre: Obviously regulatory pressure driving changes to the oils. That’s been the story of most of my career at Chevron. Those are the main drivers shaping the way engine hardware is being designed and built, and the fluids we’re developing to lubricate them.

The greatest scrutiny lately has been on vehicle efficiencies to reduce greenhouse gas emissions. But this is really a win-win for fleets. They’re buying less fuel and able to extend oil drain intervals. So, we have some parallel demands on our engine oils and we have to work hard to keep pace with all the changes.

HDT: And a new oil category is coming in 2027?

Whitacre: Yes. And that’s driving one of the biggest changes in trucking now, which is the transition to lower viscosity grade oils.

The last big oil category was introduced in 2016. These were ultra-low-viscosity fluids to boost fuel economy. In 2027, we’re going to see elevated fuel economy standards in addition to stricter greenhouse gas emissions standards. There will also be increased scrutiny on nitrogen oxide (N0x) and particulate matter emissions.

HDT: And tougher standards for emissions control systems on trucks?

Whitacre: Right. This is a big deal. These standards will apply to 2027 model trucks not just when they’re new. But new regulations will make sure those emission control systems and all the associated hardware maintains the regulated standard of performance well into the life of the equipment.

Right now, the U.S. Environmental Protection Agency and California Air Resources Board standard is that those systems must continue to perform according to regulations for 435,000 miles. The new standard will almost double that to 800,000 miles.

HDT: How does that affect the next oil category requirements?

Whitacre: Right now, engine manufacturers are designing all-new emissions control systems to meet that 800,000-mile requirement. Some small amount of oil is always going to be consumed in those emissions control systems and that can deteriorate their performance. So, we’re looking closely at our blends for the next oil category, particularly things like phosphorus and ash-control components. We need to balance those properties, so they don’t degrade those systems.

HDT: That sounds like a pretty major requirement.

Whitacre: It’s more of an evolution of the existing oil category than a wholesale change like we saw in 2016 with the combination of the C and F oil categories.

The F oil category is currently limited to a 30-weight viscosity grade. And the engine builders have opened the door to a 20-weight oil as well in 2027. In fact, we think factory fills will be with 5W/30 or 0W/20 oils. Those are the norm in Europe now and we’re seeing that trend migrate here.

But these oils are clearly being developed with an emphasis on wear performance. And we are developing new performance tests for these oils. We’re looking for better wear control. Integrating synthetics into the blends enhances oxidation stability. And we’re looking at a broader set of non-metallic materials and making sure that the new components used in the blends will be compatible with similar materials commonly found in modern engines.

HDT: So, there’s still some time — and still some work to do?

Whitacre: Yeah. The first license for the new category will be on Jan. 1, 2027. So it will line up with 2027 model trucks. We’ve still got a couple of years.

But, it’s a good reminder for your readers to periodically engage with their oil marketers — especially smaller fleets that don’t have the resources to be as cutting-edge as some of the big carriers are. It’s easy to fall into the habit of doing the same oil drains when a different selection of fluids could easily give you much longer drain intervals.

And there are other oils that can give better fuel efficiency as well as lower operating and maintenance costs. That’s going to be important as older diesel engines migrate out of the industry and newer ones move down into second- and third-life fleet service. They have a lot of attributes that lend themselves well to longer drain intervals.

HDT: Why do you think synthetic oils are gaining in popularity?

Whitacre: There is a combination of factors in play. This is a trend in the passenger car market, as well. Synthetics are almost a requirement for lower viscosity oils. Synthetics are purpose-built and tailored to provide engines with good thermal stability over a broader temperature range. We need an oil that can maintain viscosity when cold — but not get too thin when the engine is hot. Synthetic oils have a lot of inherent strengths in that area.

And all that really comes back to the additive package we develop for the base oil. That lets us build the oil in a way that meets these performance requirements. But it’s a real balancing act.

HDT: At the same time, you have a host of new powertrain and fuel technologies coming that will require new oil blends.

Whitacre: This energy transformation transition that we’re all going through is certainly forcing us to explore a broader variety of products to meet the needs of these emerging technologies.

Even with conventional engines. We’re seeing internal combustion engines burning more diverse fuels. Renewable diesel is gaining in popularity. It has properties that are nearly indistinguishable from conventional diesel fuel, so its impact on an engine is pretty minimal. But we’re doing a lot of testing to validate that so that fleets can optimize one fuel over the other.

Biodiesel is largely in the same camp as renewable diesel, although chemically it’s quite a bit different from conventional diesel fuel. There are some challenges there. But the trucking industry as a whole has gotten smart about how to use biodiesel effectively. And it’s now a viable option for fleets wanting to reduce carbon emissions.

HDT: What about fuels other than diesel?

Whitacre: Compressed natural gas is a technology that’s been around for many years. And it has some unique lubrication challenges depending on the type of fuel and the type of combustion. We were successful in threading the needle with our Chevron CNG 600 ADF oil – which was approved for use in both heavy-duty diesel engines and also in mobile CNG engines. It gave mixed fleets a single engine oil. And, as I said, that helps simplify things for our customers.

Longer term, we see liquid hydrogen ICEs on the horizon. And we are working now on trying to explore that what the lubrication requirements are for hydrogen as an engine fuel. There’s a lot of similarity with hydrogen to CNG, in terms of how it impacts an engine. And there are some new aspects that we’ll have to address. But we’re getting smarter about it all the time.

That’s kind of what we do: Stay on top of the market and stay close to the engine manufacturers around the globe. We are a trusted partner with them. It’s our job to make sure they have the right mix of fuel and lubricants they need and their customers — and ours — need.