As of dec. 1, two new engine oil blends in development for over five years are officially available on the trucking market. CK-4 and FA-4 are the offspring of the Proposed Category 11, or PC-11, engine oil classification, which gained final approval from the American Petroleum Institute (API) in January.
How does the introduction of those two oils affect your trucking operation? For starters, there are several important points to keep in mind, explains Dan Arcy, global OEM technical manager for the Americas at Shell. First, based on Shell’s testing of its new oils, there should be a 1.5% improvement in fuel economy by switching from current 15W-40 engine oil blends to the new CK-4 10W-30 formulations and higher gains with FA-4 products.
Second, longer drain intervals should result because both oils are designed to be more robust and survive in the higher-heat environment of 2017 model-year engines. Arcy says operating engine temperatures are expected to climb some 50 deg. F.
Landon Sproull, vice president of powertrain at Paccar and formerly chief engineer at Peterbilt, says oil and fuel filter change intervals for the company’s 2017 Model MX-13 and MX-11 engines will be extended from 60,000 mi. to 75,000 mi. Paccar believes this will save up to $1,000 per truck over 600,000 mi. of operation.
Sproull adds that Paccar conducted 2 million mi. of testing and oil analysis of the MX engines. “We’ve seen less soot in the oil and less degradation; that’s why we’re confident in the extended interval,” he explains.
Paccar is currently testing the FA-4 engine oil blend in its MX products and may decide to factory-fill with it once tests are completed by year’s end. “I believe we’ll recommend both oils for 2013 model-year engines and beyond, but we need to finish our tests first,” Sproull says.
Len Badal, global Delo brand manager at Chevron, adds that Detroit, the engine manufacturing division of Daimler Trucks North America, will start factory-filling all of its 2017 model-year engines with FA-4 oils starting Dec. 15; however, the OEM will also allow those engines to use CK-4 10W-30 and 15W-40 blends as well as the current CJ-4 15W-40 blend.
Badal points out that Detroit is planning to make FA-4 backward compatible for use in 2010-compliant DD13 and DD15 engines, though he stresses it is the only engine maker to date to go that far back with FA-4.
All of the other engine makers are aiming to factory-fill with CK-4
10W-30 oil, he says, though Cummins may choose to go with FA-4 in select engine models.
He also emphasizes that fleets need to remember that the fuel economy mandates within the greenhouse gas (GHG) regulations are driving the development of both of these new oils, especially FA-4.
“[OEMs] have to meet those [Phase 2 GHG] standards, not the fleets,” Badal points out. “In particular, factory-filling with FA-4 allows [engine OEMs] to gain more credits under the [GHG] program.”
If a fleet decides not to use the factory-fill oil, especially if it’s an FA-4 blend, the engine warranty won’t necessarily be invalidated. “You can’t take a CK-4 10W-40 too far back, but a CK-4 15W-40 will cover all the lanes,” he explains. “Even if you mix FA-4 and CK-4 accidentally, it’s not a big deal; however, if you keep using [FA-4] long term [in an older engine], you will see some impact.”
Still, Jeff Torkelson, technical director of engineering-tech services at Valvoline, says operators switching to CK-4 10W-30 blends should see a gain in fuel economy. “Even with the CK-4 backward-compatible oils, the 10W-30 grade should provide improved fuel efficiency compared to the 15W-40 grade,” he says.
Brian Humphrey, OEM technical liaison at Petro-Canada Lubricants, adds that new package labeling, bottle color, and user-friendly symbols should help trucking customers select the right PC-11 oil for their needs. He points out that API recently released two new service symbols, or ‘donuts,’ to help distinguish between the CK-4 and FA-4 blends, although oil marketers are allowed to use any color they choose for the donut itself.
FA-4 vs. CK-4
“Beyond the OEM recommendations, it’s worth keeping in mind that the primary difference between FA-4 and CK-4 is the level of high-temperature high-shear, or HTHS, viscosity,” Humphrey notes.
FA-4, which is designed for newer vehicles, provides a slightly lower HTHS, which enables an improvement in fuel economy because of lower “viscous drag” from the oil, he explains.
“The oils in this category have been formulated with the lowest HTHS viscosity levels we have ever seen … allowing [diesel engines] to run more efficiently and use less fuel while still offering improved levels of wear protection,” he continues. “Future heavy-duty fleet vehicles will be designed to comply with this specification to offer even higher levels of [fuel] efficiency.”
CK-4, on the other hand, will offer backward compatibility, allowing for use in the vast majority of older heavy-duty diesel engines while still offering increased performance and protection gains.
“This is because older engines are not designed to operate with such low HTHS oils,” Humphrey explains. “If your particular operating conditions push the limits of higher temperatures due to high loading, elevated ambient temperatures, or restricted cooling, then you may actually wish to forego the extra fuel economy benefits associated with FA-4 in favor of the added film thickness of CK-4.”
Likewise, if your truck’s working conditions are “extremely dirty” with excessive particles in the oil, CK-4 may be a safer choice for that equipment, he points out.
Steve Haffner, North American market manager for Infineum USA, expects the “fastest growing product” among the PC-11 oil family to be CK-4 10W-30, which provides improved fuel economy over 15W-40 blends.
“As fleets bring in more new engines, they will eventually adopt the newer FA-4 10W-30 product, when recommended by OEMs, which will provide even larger fuel economy benefits,” he believes. “While some OEMs may allow limited backward serviceability to encourage [FA-4] use, most industry observers expect CK-4 to be the product of choice for many years to come.”
To that end, in North America CK-4 engine oils are fully backward compatible in the same Society of Automotive Engineer (SAE) viscosity grades recommended for current and older diesel engines, Haffner explains. Thus, CK-4 oils will provide enhanced engine protection and be used in applications which called for CJ-4, CI-4 PLUS, CI-4, or CH-4, he points out.
Gas or diesel?
“Heavy-duty OEMs have not expressed any interest in gasoline API performance claims on heavy-duty diesel oils, and some strongly prefer oils with higher phosphorus content,” Haffner adds. “It remains to be seen if the logistics benefits provided by universal oils will be enough to overcome any perceived or real debits in diesel engine protection.”
Indeed, Chris Guerrero, global HDEO brand manager for Shell Rotella and Shell Rimula, notes that Shell’s newly updated engine oil portfolio will include a multi-vehicle synthetic blend, Rotella T6 5W-30, for both diesel and gasoline engines that will allow CK-4 blends as well as API SN performance standards. “This oil cut its teeth in the diesel setting; we did that first before seeing if it could work in the gasoline setting,” he says.
Another challenge Haffner expects with the new oils revolves around what he dubs “supply chain challenges,” which may lead to some difficult and even confusing scenarios if the needs of all consumers are to be met upon initial introduction of PC-11’s oil progeny.
“The need for two SAE 10W-30 engine oils—with one meeting CK-4 and replacing legacy CJ-4 applications and the other meeting the new lower viscosity FA-4 category—is probably the biggest cause for concern,” he says.
The key to understanding why the new PC-11 oils will ultimately benefit the industry lies in the field test results, explains Michael Smith, commercial vehicle lubricants global brand manager at ExxonMobil Fuels and Lubricants. He says ExxonMobil put its Mobil Delvac CK-4 and FA-4 oil options through some 30 million mi. of testing and found they offer an 80% improvement in high-temperature viscosity control, 50% improvement in oxidation resistance, and 20% improvement in wear protection over previous oils.
“Fleets that have been testing our CK-4 and FA-4 formulations have consistently reported exceptional results,” Smith emphasizes.
Shawn Whitacre, senior staff engineer primarily responsible for product formulation of the Delo brand of heavy-duty engine oils at Chevron, adds CK-4 and FA-4 oils have undergone some of the most rigorous, varied and exhaustive testing in the industry. He is also chairman of the American Society for Testing and Materials heavy-duty engine oil classification panel that developed the PC-11 oil requirements.
“It is important to be able to tell customers with complete confidence exactly how products will perform for them in whatever environment they may be,” he points out. “That’s why a wide diversity of testing in different engine types and under different operating conditions is absolutely critical.”
Whitacre notes that the early stages of PC-11 development focused on passing specification tests—tests prescribed under controlled conditions designed to evaluate oils quantitatively in an accelerated fashion. While lab testing provides valuable information, it may not necessarily reflect real-world performance.
“Industry-standard testing also tends to emphasize on-highway performance, but you don’t want to overlook off-highway needs,” Whitacre explains. “That’s why it’s important to run tests in collaboration with customers that expose oils to a broader variety of operating conditions, duty cycles, temperatures, and other environmental factors that are important to understand.”
That means taking multiple products across various viscosity grades and testing them in different engines spanning a range of manufacturers, including engine types that aren’t used in the standard specification tests.
“Within the on-highway category, we look at different types of operations—tractor-trailers, garbage trucks, pickups, and others. We also test in farm equipment and different types of off-highway operations,” he stresses.
Field testing takes time, including several years through different seasonal and temperature changes, Whitacre notes. “In a heavy-duty engine, it’s not really instructive to do [tear-down] inspection before 500,000 mi.,” he says. “If you figure a truck averages 100,000 to 200,000 mi. a year, it could be three to five years before a tear-down test will yield meaningful analysis.”
Shell’s Arcy notes that his company conducted 40 million mi. of on-road prototype formulation testing for its PC-11 oils and 50,000 hours of off-road testing for its CK-4 product line. This included testing in tractor-trailers and diesel pickup trucks as well as in gasoline engines.
Howard McIntyre, vice president for lubricants at Suncor, Petro-Canada’s parent company, stresses that PC-11 is the “biggest step change” that the North American heavy-duty truck market will experience.
“This is not only an opportunity to improve the efficiency and carbon footprint of heavy-duty vehicles, but it is also a chance to recognize the potential to cut costs and increase the profitability of operations,” he adds. “As with all business decisions, a clear understanding and early adoption could result in a genuine competitive edge.”