ILSAC GF-6: Light at the End of the Tunnel?


HOUSTON – The semi-annual ASTM meetings here last week included discussions by several groups at the center of engine oil specification development, and they appeared to make significant headway toward adoption of the long-delayed ILSAC GF-6.

A variety of committees reported progress on several tests that help make up the next full upgrade to North American passenger car engine oil standards. It now looks possible that GF-6 could be finalized by the end of the first quarter of 2018.

The Passenger Car Engine Oil Classification Panel and Auto/Oil Advisory Panel both accepted the Sequence X, a new test for chain wear that is being added to GF-6. The wrap-up of work on the Sequence X leaves just one test still to be approved for GF-6 – the Sequence IVB test for valve train wear. The Sequence IVB, which is replacing the Sequence IVA, has been undergoing testing meant to verify that it is repeatable and that it adequately discriminates between oils that provide the valve train protection it is meant to measure, and those that do not.

Interteks Bill Buscher reported that significant progress has been made and the precision matrix will complete this month. He shared data indicating that the test appears to discriminate between passing and failing reference oils and that the industrys two main test labs are showing consistent results. If the matrix continues to go well, Buscher predicted, the IVB will be presented for final approval in February during industry meetings scheduled in San Antonio.

The Category Life Oversight Group discussed work it is doing to set limits on tests that will be part of GF-6 as well as API SN Plus, the supplemental oil category that the industry is trying to develop to tide it over until GF-6 finally comes to market. Members said work on the Sequence VIF test for fuel economy, which will be part of GF-6, are finished and that they are moving closer to agreement on limits for the Sequence VIE, which is being developed as a replacement for Sequence VID.

The VID is no longer available, and this led API earlier this year to invoke provisional licensing for specifications that include it, so industry is eager to complete work on its replacement test. Automakers have asked for stricter limits than those proposed by CLOG. The same is true for the Sequence VH test for sludge and varnish. Both items were passed onto APIs Lubricant Group for final resolution.

Fords Ron Romano predicted that GF-6 could be finalized by the end of March, assuming that the Sequence IVB is accepted in February. That would queue licensing of the specification to begin around the first quarter of 2020.

The other key meeting was led by Rick Dougherty of ExxonMobil regarding base oil interchange and viscosity grade read across, which dictate the extent to which formulators may substitute part of the base oil content of an approved oil without being required to redo testing that is part of the spec. Individuals attending the meeting said enough progress was reported that the group signed a memorandum of understanding to release funds for test matrices.

Among the tests included in this exercise are the Sequence IX for low-speed pre-ignition, which is part of SN Plus, and the Sequence VIE, another source of provisional licensing. If that testing goes well, SN Plus appears on track for first allowable use on May 1.

There was also discussion about the Sequence IIIH test for oxidation performance and control of deposits, which is part of older API S and C categories. The Heavy Duty Classification Panel reviewed and accepted limits on viscosity increases, and this should enable API to keep CH-4, CI-4 and CJ-4 as active specifications. Engine manufacturers would like to do this because they believe there is still demand for them among truck operators.