By John Smith
Every category of engine oil is supposed to be better than the one it replaced, and the CJ-4 engine oils that were introduced in 2006 were no exception. They offer better protection for rings, liners and valve trains; improve oil consumption and piston deposits; and address soot-related wear.
But when given the choice, many buyers opted to stick with the CI-4 Plus oils that were already on the market – despite the fact that CJ-4 would work in new and old engines alike.
“This was one of the only times in the history of the heavy-duty motor oil market that we had two oils in the market at the same time,” observes Nicole Fujishige, commercial marketing manager, Chevron Global Lubricants.
It was a unique situation. The main reason the trucking industry needed this new category of oil was to protect the diesel particulate filters (DPFs) that became a staple of heavy-duty emission controls in 2007. That meant little to someone who bought trucks in 2006, just before the new emission-cleaning equipment was introduced. Besides, Cummins even announced that CI-4 Plus engines could be used in 2007-compliant engines.
Some of the reluctance to adopt the newest oil formulas may even be linked to a simple misunderstanding about total base numbers (TBN).
Maintenance teams had been told for several years that a higher TBN was a good thing. It was seen as a measure of how well the oil was equipped to counteract the acids produced through the exhaust gas recirculation (EGR) process. But the CJ-4 oils needed a lower TBN to ensure that new DPFs were not prematurely plugged with ash.
