The American Petroleum Institute closed provisional licensing, invoked in March for most active North American industry heavy-duty diesel engine oil specifications because independent laboratories were unable to run the Mack T-12 wear test.
The Mack T-12 test measures an oil’s ability to prevent wear in turbocharged intercooled diesel engines that are equipped with exhaust gas recirculation and that operate on low-sulfur fuel. The test is required for the two newest industry heavy-duty oil specifications in North America – API CK-4 and API FA-4 – as well as four earlier specs that are still active: API CJ-4, API CI-4 Plus, API CI-4 and API CH-4. The provisional licensing is ceasing for all of those specifications.
“Marketers with formulations that have been provisionally-licensed must now obtain a passing Mack T-12 result within six months from the date of this notification,” Jeffrey Harmening, manager for API’s Engine Oil Licensing and Certification System program, said in a Sept. 15 notice to EOLCS licensees, the API Lubricants Group and other interested parties.
Industry groups had temporarily halted Mack T-12 testing after observing higher than normal oil consumption measurements following introduction of the new batch of parts for the Mack T-12 engine. The Mack/Volvo Surveillance Panel on Sept. 10 notified industry stakeholders and interested parties about the return of the engine test to available status.
“Through testing, the F batch piston crowns were found to contain a subgroup of parts that produced oil consumption measurements in the expected range of previous batches of hardware,” the panel explained in its notification. This piston subgroup underwent coordinated reference testing at test labs, and the surveillance panel said it agreed to industry correction factors for the batch of parts. The test labs obtained calibrated status as of Sept. 13, the panel noted.
API’s provisional licensing enacted in March – and scheduled to last until Sept. 17 – meant that lubricant marketers seeking new licenses for heavy-duty oils temporarily needed to do so without being able to demonstrate a key performance parameter. It added to a series of such disruptions that impacted the market’s engine oil licensing system the past few years as problems with test availability became more frequent. For example, in 2020 provisional licensing was invoked over the unavailability to a key bench oxidation test for ILSAC GF-6 and API-SP, along with additional then current standards, citing a backlog of testing in advance of GF-6’s May 1, 2020, first-licensing date. That provisional licensing invocation allowed engine oils meeting other requirements to obtain approval for meeting the specifications in question without having to pass the Romaszewski Oil Bench Oxidation test.