The current CJ-4 oil category of oil for diesel engines that farmers and dealers are familiar with is living on borrowed time under new fuel economy demands and CO2 mandates.
Diesel engine manufacturers have spent billions of dollars and the better part of the first 14 years of the new century bringing their products in line with the political demands for cleaner exhaust. Throughout the changes in engine design made possible once the U.S. had switched to ultra-low-sulfur diesel fuel, the familiar "CJ-4" American Petroleum Institute (API) engine oil category served well in engines designed to meet EPA Tier 2 through Tier 4 emission standards. The CJ-4 rated oils continue to provide protection to even the newest engines, but engine manufacturers still face more mandates - namely reducing CO2 emissions and improving fuel economy in varying stages from 2014-2018.
Dan Arcy, Shell Global Solution's OEM technical manager, and chairman of the New Category Evaluation Team (NCET), says the Truck and Engine Manufacturers Assn. proposed the new category in June 2011, and set an early 2016 date for licensing a new category - likely CK-4 - heavy duty motor oil for on- and off-road diesel engines.
"That was a tall order," Arcy explains, and one that was compounded by the fact many of the test engines and other equipment used to test and certify the current CJ-4 classification are obsolete or no longer exist. "Also, the manufacturers wanted additional tests for the new oil, specifically tests for oxidation stability, scuffing protection and shear stability, along with tests for aeration," he says.
"In early June, the NCET looked at the delays and the time it has taken to map the tests needed, and put a first quarter of 2017 date on the launch of the new oil," he says.
The group has settled on the MACK-T13 test, a grueling 360 hour marathon of engine operation at high load of 1,500 rpm and with a 130 C oil temperature for the oxidation stability challenge. "This is similar to tests for existing specifications, only more stringent," Arcy explains. "For the aeration test, the new oils will be subjected to a 50 hour challenge in the CAT Aeration Test to look for air entrainment within the oil during engine operation." As this planning progressed, the new oil has been labeled PC-11 but the story gets more complicated at that point.
First, fleet operators want backward compatibility for new oils, so a future CK-4 engine oil would serve engines designed to operate on oils rated at the CJ-4 and earlier classification capabilities. That's understandable, but maybe not possible with lighter viscosity oils that will be necessary to reduce friction in lubricants designed to improve fuel economy, Arcy explains. "That means PC-11 became PC-11A (backward compatible oils in the 5W40, 15W40 and 10W30 traditional weights to which today's' fleet operators are accustomed) and a PC-11B which would include the lighter viscosity products designed for improved fuel economy while not compromising engine life and durability."
Arcy says the PC-11A oil likely will be labeled CK-4, denoting the next alphabetical level, "K", in oil capability for compression ignited 4-stroke engines. "That oil will offer manufacturer's warranty level protection for older engines designed for CJ-4, CI-4, etc.," he explains.
"We have no idea what the PC-11B oils will be designated, and we don't know if they will be backward compatible with the traditional heavy duty engine oils customers are using."
What About Ag?
"As all this evolves, things can and do change," Arcy notes. "Both John Deere and Caterpillar have seats on the new category development team as 'off-highway' representatives. From their standpoint, their interest in the new oils pertains mainly to the PC-11A higher-viscosity oils," he says, meaning farmers and farm equipment dealers may only be dealing with a new CK-4 category in 2017 - unless significant changes occur to warrant additional OEM attention to fuel economy.
Where to Now?
With agreement on the tests necessary, NCET says the next step is arranging the tests and establishing a precision in those tests that will allow for repeatability (the same results each time the test is done within a lab) and reproducibility (the same results each time the test is done from lab to lab).
"After that, we will begin running engine tests, probably in August and early September, to understand what we're going to need to do to meet the specifications," Arcy says. "We'll have actual pass/fail limits in place set by the NCET, the ASTM heavy duty engine oil classification panel and the API diesel engine advisory panel."
Dan Crummett has more than 30 years in regional and national agricultural journalism including editing state farm magazines, web-based machinery reporting and has an interest in no-till and conservation tillage. He holds B.S. and M.S. degrees from Oklahoma State Univ.