NEW ORLEANS – Although managers of heavy-duty truck fleets understand the fuel economy benefits of API FA-4 engine oils, many remain hesitant to use a lower-viscosity heavy-duty engine oil, an industry insider said at a conference here.
Fleet managers are very nervous about having multiple oil grades inside their terminals, Jason Bieneman, manager and head of technology for Mahle‘s North American Engine Components Group, told Active Communication International‘s U.S. Base Oils and Lubricants Summit on Aug. 29. “They don’t want to take the risk of putting that low-viscosity oil into another piece of equipment, having it fail in the field or have to replace it early,” Bieneman said. Concerns about ancillary equipment such as refrigeration units and auxiliary power units also come into play for fleet managers, he explained.
However, he noted, the fleet managers are aware of the FA-4 oils’ fuel economy benefits. “The flip side is they are not very happy about having to give up the fuel economy,” he said. “They’ve seen from that first oil change, that those trucks are able to get 1 to 2 percent better fuel economy – they’re able to actually measure it. They want to get there, and they want to get there as fast as they can. But they want to take a little bit of time until they’re able to start refreshing the full fleet at those terminals, and then they can completely switch over.”
Bieneman estimated the on-highway, class 8 truck fleet at about 3.5 million. “What’s produced and in-market since the 2017 release of FA-4 oil is about 9 percent of that fleet, or about 320,000 vehicles,” he said. Of that, among truck original equipment manufacturers only a small fraction allow the use of FA-4 oils in their trucks engines, he noted. “Its getting down to maybe 100,000 to 110,000 vehicles that might be either compatible with or available with that oil,” Bieneman said, adding “that’s why the amount of [FA-4] oil volume being consumed is relatively low.”
FA-4 and CK-4 are the latest diesel engine oil categories from North America’s engine and lubricant industries. Introduced in December 2016, CK-4 was developed to provide improved performance in 2017 and older on-highway trucks, except for new trucks designed to meet a 2017 mandate limiting greenhouse gas emissions. Trucks subject to that regulation have fuel economy requirements, which FA-4 was developed to help achieve. But FA-4 was developed specifically for those 2017 trucks and not for use in ones made in previous model years.
Use of API FA-4 has been limited by the issue of backwards compatibility. The heavy-duty diesel fleet in North America averages 14.4 years in age. The older engines in service require a high-temperature, high-shear rate viscosity of at least 3.5 centiPoise, while API FA-4 specifies HTHS viscosity of 2.9 to 3.2 cP.
A myriad of factors hinder adoption of FA-4 oils, he said, including the very different demands imposed on trucks, depending on their usage. “Not all vehicles look the same,” he said. “Not all OEMs have the same starting point. Fleets are very diverse – delivery trucks, long-haul trucks and down to pickup trucks.”
Ford Motor Co. in 2018 amended its engine oil guidance for small-engine diesel-powered pickups, including the diesel version of the F-150, to recommend API FA-4 oils. The decision represents a slight softening of the automakers’ cautious stance toward the newest diesel engine oil categories. Daimler’s North American subsidiary uses FA-4 for factory fill, and the company also recommends it for engines going back to model year 2010.
Although low-viscosity engine oils have a role to play in helping meet tougher vehicle emissions standards, Bieneman noted that truck OEMs are pursuing many different ways to help meet those goals. “We know customers are looking at design of the truck, tires, trailers, aero packages – all those things to help them get to that number,” he said. “Other technologies truck OEMs are using that have emissions reduction benefits include autonomous and semi-autonomous driving and predictive cruise control. Also gaining popularity are waste heat recovery systems which capture heat generated by the engine – whether from its exhaust or cooling system – and direct it back to the power train system.”
Trucks for off-highway use present additional challenges because of the much different working environments, equipment uses and equipment ages, according to Bieneman. “Where it starts to get more interesting is diverse duty cycles and the extreme operating environments they are working in, which sometimes makes looking at the benefits of lower-viscosity oils a little more difficult for those operators,” he said.
Bieneman noted that some of the bigger challenges stem from the need to operate the trucks at remote sites, where it can be difficult to get oil in general, but also difficult to get multiple grades of oil. “Repairs being done on-site provides some interesting challenges, with the higher likelihood of introducing debris and dust into the engine when repairing it,” he explained. “So now that we have those coming in, we get that in the lubrication system and tend to see accelerated wear rates.”