While many fleets may be looking at potentially extending their drain intervals beyond the engine OEM recommendations, those recommendations themselves are much longer now than they have been in the past. This trend has been ongoing for years, but recently got a boost from the introduction of the new API CK-4 and FA-4 oil categories.
“The new API CK-4 and FA-4 oils are designed to provide greater protection in modern diesel engines,” said Mark Betner, heavy-duty sales manager for Citgo. “This is important because these modern engines have multiple factors to consider such as higher operating temperatures, high ratio timing gears and higher fuel injection pressures. These factors, combined with the introduction of low viscosity and more fuel efficient engine oils, means that engine durability and wear protection must also be maintained.”
“Both of the new categories have oxidation requirements that are more stringent than what we had with the previous category, API CJ-4,” said Dan Arcy, global OEM technical services manager for Shell Lubricants. “That has allowed for the opportunity to extend drain intervals on a lot of on-highway trucks. All the new manufacturer recommendations on the new engines reflect this.”
Jason Johnson, director of aftermarket for PACCAR, Inc., pointed out that CK-4 and FA-4 oils come with optimized additive packages that have yielded oil stability improvements, leading to longer intervals. “Modern engine oils have been optimized for longer drain intervals than in the past while still offering the engine protection that fleets depend on,” he said.
It is important to note that each engine recommends a different category of oil, with some offering FA-4 as an option and some only recommending CK-4. Detroit, for example, approves FA-4 for use in all of its EPA10 and newer engines, pointed out Greg Braziunas, manager of transmission, clutch, fluids and test planning for Daimler Trucks North America. This is important information to keep an eye on for whichever brand of engine you might have, so be sure to be aware of the recommended oil when spec’ing new engines as well as the drain interval.