Wear Test Gets Vote Despite Debate


The Sequence IVB engine test, the final test for the much-delayed ILSAC GF-6 engine oil category, cleared a major hurdle this month when the Passenger Car Engine Oil Panel recommended it be adopted as an ASTM procedure.

Debate continues, though, about whether the test does its job of measuring whether oils adequately protect against low temperature engine valve train wear.

The Auto/Oil Advisory Panel (AOAP) – jointly representing the International Lubricant Standardization and Approval Committee (automakers) and the American Petroleum Institute – issued an electronic ballot for the tests acceptance into ILSAC GF-6, and the tally is scheduled to conclude March 30.

The Sequence IVB will be officially adopted by ASTM but stakeholders must still agree it is ready to be accepted into GF-6, and it also must be approved into the ACC Code of Practice. Completion of those tasks will start the clock on a 19- to 27-month waiting period before the long-awaited passenger car motor oil category can formally enter the market.

GF-6 was supposed to have been the first PCMO upgrade since GF-5 and its companion category, API SN, were adopted in 2010. The repeated delays for GF-6 led to development of a supplemental category – API SN Plus – which is due to come to market in May or June.

The Sequence IVB was developed to test an oils ability to prevent low temperature engine valve train wear. Some observers, however, have complained that it does not sufficiently distinguish between passing and failing reference oils and therefore does not provide an adequate level of protection.

At a March 7 meeting of the Sequence IVB Surveillance Panel, additive supplier Lubrizol reported on the poor proof of performance on an oil that they submitted with significantly less anti-wear additives than an oil meeting todays latest standards. This oil showed clearly failing results for the Sequence IVA test – a procedure in GF-5 that the Sequence IVB is replacing – and modeling predicted that it would have clearly failed the old Sequence VE test for valve train wear. Yet the oil achieved a passing score on the Sequence IVBs limit for average intake lifter volume loss.

The panel suggested adding another limit to the test – a measurement for used oil iron level that would account for all wear seen in the engine. Lubrizol noted that its poorly performing oil passed the suggested iron limit and cited this as its reason for voting against the tests acceptance. The company contended that the Surveillance Panel needs more time to consider key developments that were introduced at the surveillance panel meeting, particularly the addition of end-of-test iron as a pass/fail parameter.

ExxonMobil presented encouraging data on two other poorly performing oils showing clearly failing levels of iron and higher valve train wear results. The energy giant claimed this demonstrated that a solution can be found. Others agreed with Lubrizols position that the test is not ready for inclusion into GF-6 at this time. Those companies generally indicated they did not object to the test be accepted into ASTM while work continues.

Teri Kowalski, chief engineer with Toyota Motor North America, made the following motion at a meeting of the Sequence IV Surveillance Panel, also held March 7: The Sequence IV Surveillance Panel, having secured hardware supply, test fuel and reference oils for a test procedure that measures the performance of passenger car motor oil for low-temperature engine wear, recommends to the Passenger Car Engine Oil Classification Panel, the Auto Oil Advisory Panel and the American Chemistry Council that the Sequence IVB test is ready for inclusion in ILSAC GF-6 and that the Sequence IVB procedure be published as an ASTM method. Realizing that the test parameters (average intake lifter volume loss and maybe iron content) need to be finalized, and the [Lubricant Test Monitoring System] still needs to be developed.

The motion passed at the surveillance panel with 11 votes in favor, two against and eight abstentions.

ILSAC Chairman Ron Romano, of Ford, said committees can continue fine-tuning the test to shore up any deficiencies before marketers begin selling oils labeled as meeting GF-6.

Ford Believes the new Sequence IVB is a suitable valve wear test and believes it will provide enhanced wear protection versus the current Sequence IVA in protecting old and new engines, he said. The GF-6 specification must have a valve train wear test, and the latest recommendation to add an iron limit would enhance the test to ensure wear protection for the entire engine. I am convinced that the team working the test will develop a path forward that will meet the needs of all stakeholders.

In other news concerning GF-6, it appears that all other tests are making good progress with base oil interchange and viscosity grade read across guideline work. This appears on track to be completed by end of the second quarter. Discussions concerning the specification and test limits are underway, and stakeholders are taking a hard look at the various steps to finalize a schedule including the tech demo period and mandatory waiting period. Stakeholders continue to meet monthly to ensure delivery of the new specification as soon as practical.

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