The report was given at the Diesel Engine Oil Advisory Panel meeting, immediately after the Heavy Duty Engine Oil Classification Panel’s meeting. EMA spokesperson Tia Sutton said engine manufacturers do not see a need for a new category prior to 2027 when new environmental regulations for trucks and buses may go into effect. New requirements will be determined, based on any new federal regulations or regulations from the California Air Resource Board, which have yet to be determined. This timing is consistent with previous feedback, which called for PC-12 to come to market between 2025 and 2027.

There were no significant discussions of potential technical needs for a new category at this time. Stakeholders have previously discussed potential changes to the chemical box and potential reductions in oil viscosity, along with better oxidation control.

Attendees expressed alarm about the outlook for hardware used for engine test programs for the latest industry heavy-duty specifications, API CK-4 and FA-4, and for older licensable categories. Judging from presentations at both the Diesel Engine Oil Advisory Panel and Heavy Duty Engine Oil Classification Panel and based on current test usage, many key engine tests could become unavailable as early as 2024, well before the need for a new category.

The older categories that stand to be impacted are API CJ-4, CI-4, CI-4 plus and CH-4. As part of its update, EMA proposed to make CH-4 obsolete within the next 12 months and to streamline CJ-4 and CK-4 into one specification, possibly with less testing. The key tests in question included the Mack T-8, T-11 and T-12 test methods. One suggestion would move the liner wear parameter from the T-12, a critical measurement taken on a Mack diesel engine, to the Volvo T-13 engine. Mike Allessi of ExxonMobil reminded the group that the original goal for CK-4 was to eliminate the need for the T-12 test, but the metallurgy from the T-13 testing hardware was just too good. This forced the industry to keep the T-12 test in addition to the T-13 for oxidation testing.

Lubricant marketers opposed the elimination of CH-4. According to API, a significant number of companies still hold API licenses for CH-4, and Mexico was introducing its own engine oil standards, where CH-4 performance would be the minimum quality level for heavy-duty diesel engine oils.

Sources note that CI-4 by volume is the largest commercial product by volume globally, and EMA commented that it meets its member needs around the world. This is a dilemma, as maintaining older categories gets more difficult, and CH-4 is now over 20 years old. Keeping it potentially increases demand for engine tests to run any new programs.

Eliminating CH-4 has pros and cons. It simplifies needs for the industry and may have supply chain benefits. It can also lead to many end users upgrading the quality to CI-4 if they want an API licensable product to protect older equipment. On the downside, it could lead to un-licensable oils that may not be as robust as a licensable product. The latter exists today with obsolete categories, such as API CG-4, CF-4, CD and CF. It should be noted that additive companies have vast databases to design products that meet these older requirements if needed. Therefore, they can still supply additives to meet those needs if desired, even if they cannot run an approved API program.

The industry does not appear to have any desire to eliminate CJ-4, which actually has the most API licenses around the globe at this point in time, just ahead of API CK-4. Additive companies and marketers pointed out the urgency to begin work now on new or replacement engine tests to ensure that industry can maintain both the old and newer categories prior to PC-12. They suggested that time is already short because test development can take five years. All current diesel engine tests at risk of becoming obsolete will be under the control of the Category Life Oversight Group, now led by Brent Calcut of Afton Chemical.