The development of a new heavy-duty engine oil category (HDEO) is an expensive undertaking, the cost of which is generally reflected in the price tag and passed along to end users. The good news about Proposed Category 11 (PC-11), set to roll out in April 2016, is that customers will most likely see noticeable fuel savings as well as better performance out of the new oil.

PC-11 has been necessitated by the engine developments aimed at improving fuel economy and reducing greenhouse gas regulations in accordance with recent standards imposed by the US government.

Reflecting a slow-moving migration towards low-viscosity engine oils, PC-11 will be a split category: one will address traditional 15W-40 engine oils and the other will apply to lower-viscosity engine oils, such as 10W-30s.

Fleets will still be able to choose their preferred grade of oil, but by 2016, when the new category takes effect, most engine manufacturers will be recommending the lower-viscosity oils, predicts Dan Arcy, global OEM technical manager with Shell Lubricants.

“Those will probably be the primary recommendation for all 2016 engines when they come out,” Arcy said of low-viscosity engine oils. “Those oils will provide better fuel economy than what we get out of current 10W-30s and much better than what we see out of current 15W-40s.”

But the new category may also present challenges. Fleets will likely have to stock two motor oils: PC-11 for new engines built in 2016 and beyond, and today’s CJ-4 oils for existing equipment. Whatever the split, it’s likely 15W-40 engine oils will take up less shelf space as the industry warms to the idea of running lower-viscosity engine oils.

Even fleets that have already transitioned to lower-viscosity engine oils in the pursuit of fuel savings will see further benefits when the new category is rolled out. This is because the PC-11 10W-30s will feature improved high-temperature high-shear properties – basically a thinner film – than seen in today’s 10W-30 oils.

“Most OEMs are already factory-filling with 10W-30,” said Len Badal, commercial sector manager with Chevron Lubricants. “Today, you have a traditional film thickness for 10W-30 and we will give that 10W-30 a little bit narrower film thickness, so it gives better fuel economy performance, even above a traditional 10W-30.”

Shell’s Arcy says fleets moving from a 15W-40 to a 10W-30 today can achieve fuel savings of about 1.6%; going from a 15W-40 to a PC-11 grade 10W-30 will provide even greater fuel savings, though it’s too early to give specifics.

“What fleets and owner/operators should be excited about, is the potential for fuel economy savings,” added Barnaby Ngai, category portfolio manager, transportation oils, Petro-Canada Lubricants. “That alone can offer quite a bit of benefits. It’s a fact that fuel makes up a good portion of the expenses as it relates to the trucking industry, so any savings around that would be quite beneficial. But also, when you move towards a lower-viscosity, higher-performing product, you’re going to get additional performance benefits from protection, cold temperature properties and things along those lines.”

While OEMs are factory filling with lower-viscosity engine oils and some large fleets have made the switch, many operators still wonder about the thinner oil’s ability to protect the engine and its internal components. But all oil manufacturers claim their 10W-30s offer protection equal to their 15W-40 products. Chevron at the Mid-America Trucking Show took it a step further and performed an engine teardown on a Detroit Series 60 engine with 412,000 miles on it, to highlight this point.

“People want tangible proof,” explained Chevron’s Jim Gambill.

He said the fuel savings that can be achieved today by switching from a 15W-40 to a 10W-30 amounts to about $900 per year.

While the lower-vis engine oils may cost slightly more, he added, “they’re not a lot more expensive relative to what you save.”

So, how do lighter-weight engine oils save fuel? Gambill explained it this way: “Fundamentally, it’s the thickness of the oil. If you think about pumping oil around that engine 2,000 times per minute, that’s a parasitic load. If the oil is a little bit heavier, that parasitic load is a little more than if it was lighter. If you have a little less energy going to pump that oil around, you have a little more energy that can push through to the drivetrain or (provide) fuel savings.”

Or, as Ngai said, “It’s like swimming in a pool filled with water versus molasses. You’re going to expend a lot less energy getting from Point A to B.”

With a new category and OEMs collectively ushering in the more widespread adoption of low-viscosity engine oils, J.P. Soucie with Castrol distributor Wakefield Canada, says it’s a great time for truck owners and maintenance managers to re-evaluate their traditional decision-making processes.

While he acknowledged adopting a 10W-30 oil today or in 2016 will bring some fuel economy benefits, that change alone just scratches the surface of an oil’s ability to drive fuel savings.

“As a fleet operator or owner/operator, if you are looking for fuel economy, synthetics are designed to accomplish that specific goal,” Soucie said.

“If you’re looking for fuel economy, you need to get a fuel economy synthetic or semi-synthetic.”

Most 10W-30s currently on the market provide some fuel savings because of their thinner composition, but weren’t designed to deliver this benefit, Soucie explained.

“I think if you’re going to make the change (to lower-viscosity oils) anyhow, if you’re going to make that paradigm shift in your head and in your fleet to go to a 10W-30, why not take advantage of the technology we as oil manufacturers need to (develop) to keep up with the OEMs and go to the next step? Semi-synthetics lower your total cost of ownership and have a significant impact on your cost per mile.”

While OEMs increasingly have green-lighted the use of low-viscosity engine oils in their products, Lilo Hurtado, applications engineer for ExxonMobil, warned at the Technology & Maintenance Council meetings in March that a switch to lighter-weight oils should only be made in consultation with OEMs.

Fleets should still check with engine manufacturers to find if the low-viscosity oils are a fit, particularly when working with older engines and severe duty cycles, Hurtado said.

“Be very specific,” Hurtado said of requests for low-viscosity oils.

While the new PC-11 category will undoubtedly push low-viscosity engine oils closer to the mainstream, it won’t likely fully displace 15W-40 oils anytime soon as the predominant formulation used in the trucking industry – at least not by 2016.

“I still believe 15W-40 will be the bigger volume grade, however I think you’re going to see segments of the market – like the large- and mid-sized fleets – completely converted over to 10W-30 or in the process of doing it,” Chevron’s Badal said. “If you look at the smaller fleets and owner/operators, who sometimes run older equipment, it could take another 10 years or so before all of them come over.”

But when faced with the prospect of managing two different engine oil viscosities, Soucie said he anticipates more fleets will make the wholesale switch to 10W-30 oil when 2016 rolls around.

“Lots of fleets have challenges just managing one viscosity, and making sure it’s not topped up with a different brand,” Soucie said.

While it may be premature to speculate on the need for future HDEO categories beyond PC-11, the US government’s push for greater fuel economy from heavy-duty trucks is not likely to abate.

US President Barack Obama has already announced further standards for model years 2018 trucks and beyond.

Asked if the next set of fuel economy standards/GHG reductions will require the creation of another new engine oil category, Shell’s Arcy said it’s too soon to say.

“If you go back and look, historically every time we had a change in emissions standards with the exception of 2010, we always had a change in engine oil formulation in order to protect the new engines,” Arcy said. “What’s going to happen in 2018-2020? We’re not sure yet.”