One of the first points to make here is that both GF-6 and PC-11-the development category for the American Petroleum Institutes CK-4 and FA-4 heavy-duty diesel engine oil categories-were proposed at essentially the same time. According to industry sources, both originally had a goal to be in place before 2017. However, PC-11 had fewer new and replacement tests to be developed, so it was easier to complete than GF-6.

Thats all well and good, but somewhere along the line GF-6 got bogged down. The deadline was being driven by estimates of timing for each of the new and revised engine tests, which were being managed by the test development teams and test sponsors (automakers).

This is probably a good point to indicate which tests for GF-6 are being upgraded or added. As you read the table on page 8, the one thing that jumps out is the fact that only the Sequence VIII is unchanged. Four engine tests are being upgraded and three are completely new. GF-5 has only five tests in total, while GF-6 has eight! That is a big, big chunk of testing to develop.

Some of my sources tell me that PC-11, which added two new tests and modified some of the limits on other tests, may have cost in excess of $350 million. Can you imagine what the cost for four revised tests and three new ones could run?

When you look down the list of tests, youll find a number of different reasons why its been a struggle to get to the finish line. I thought Id note some of the biggest impacts in order for you to get the flavor of this endeavor.

Sequence VI:
Fuel Economy

The Sequence VID replacement test started out as an upgrade to new hardware. As such, it was moving along at a generally acceptable pace. Remember, since API categories must be backwards compatible to earlier categories, new engines used in a particular test must measure the same parameters. The Sequence VIE is designed to give comparable results to the Sequence VID when measuring the fuel economy improvement of GF-5 oils.

However, somewhere in the middle of all of this, a new viscosity grade, SAE 0W-16, was introduced to the marketplace. The accepted Sequence VI testing method doesnt work properly with the lower viscosity grade, so the Sequence VIF was developed.

To add to the stress, the Sequence VID has now gone defunct. The required General Motors engines are no longer available, and with a projected GF-6 introduction not expected until mid-2019, the need for fuel economy testing is in limbo unless the Sequence VIE is accepted by ASTM International and soon. The approach that API and ASTM have taken is to test GF-5 oils currently in the marketplace in the Sequence VIE and harmonize the results. That is, use the known Sequence VID results on these oils and compare them in the Sequence VIE to establish some limits that can be used to evaluate and approve GF-5 level oils.

Sequence III: Wear and Oil Thickening

The Sequence III has historically been developed with GM engines. However, GM indicated last year that the forecasted timing for GF-6 (2019 until 2023 at a minimum) does not align with GMs engine architecture/performance plans and its own Dexos test development plans. General Motors has not planned to have the manpower and time necessary to maintain two oxidation and deposit tests simultaneously. That created a bit of a quandary for the industry.

In the meantime, Fiat Chrysler developed an oxidation test and offered it as a replacement for the Sequence IIIG. This test has jumped through all of the hoops and is slated as the Sequence IIIH.

Sequence IV: Valvetrain Wear

The Sequence IVA used a Nissan engine and measured valvetrain wear. The Sequence IVB uses a Toyota engine with similar valvetrain architecture. The problem is that the proper set of operating conditions has not been found to get a correlation to the earlier test. This creates an issue with backwards compatibility. A number of different procedures and hardware setups have been tried, and one was tentatively chosen to run in the precision matrix.

Unfortunately, midway through the matrix, the Sequence IV Surveillance Panel identified some procedural changes that were necessary. Those are being reviewed, and the precision matrix will be restarted with the agreed-upon improvements, targeting first quarter 2018 completion and data review. Suffice it to say, at this point, the Sequence IVB is one of the major issues delaying GF-6.

Sequence V:
Sludge and Varnish

The Sequence VG replacement, Fords Sequence VH test for sludge and varnish, has been accepted by both API and ASTM as suitable for use in GF-6. Thats a bit of success to claim. The current Sequence VG is still available for the foreseeable future.

Thats the status of current tests. Its a tough road ahead.

The new engine procedures are also moving ahead. The Chain Wear Test is in post-precision-matrix mode. Statistical analysis showed some variations in hardware, so all of the labs are adjusting to have common positive crankcase ventilation systems. The test does discriminate and seems to be measuring soot loading in the oil as a problem.

LSPI

Low-speed pre-ignition is the hot topic at this point. The LSPI test has already been developed and approved to be published as an ASTM procedure (Sequence IX?), so automakers believe that candidate oil testing can start immediately. Thats important, because the OEMs want to move ahead with an updated or augmented version of GF-5 in order to bridge the gap between GF-5 and GF-6.

On July 20, ILSAC published a proposed GF-5 Plus specification. They requested that the LSPI test be included in addition to the existing GF-5 requirements, and that Sequence IIIH be allowed as an alternate to Sequence IIIG with some modified test limits. They also included the SAE 0W-16 viscosity grade and added Sequence VID result limits.

Im sure you have recognized that Sequence VID ran out of parts some time ago, so the ILSAC proposal rests very heavily on the work being done to harmonize Sequence VIE results with GF-5 performance limits. Will the fun never end?

API SN Plus

The API Lubricants Group met on Aug. 15 and again on Sept. 14 to discuss ILSACs proposal. The September meeting produced several actions and outcomes. The designation for the intermediate specifications became API SN Plus and SN-Resource Conserving Plus. The API 1509 fast-track process for heavy-duty engine oils in Annex D will be modified and used to add the two designations. This process may well be documented in the main body of API 1509, to be available for future categories as required.

The API donut symbols will be revised to reflect the new oils, and the API starburst will be allowed for oils meeting API SN-RC Plus. SAE 0W-16 will not carry the starburst, however.

The LSPI test was accepted with limits as proposed for GF-6.

A long and detailed process has also been developed to try for a first license date for SN Plus in the first quarter of 2018.

The question is, will ASTM be able to formalize the LSPI test in time for the January 2018 target? Its tough to predict the timing, but efforts are underway to make sure the test is ready as soon as possible. The same has to go for the Sequence VI machinations.

The capper to all of this is that there is already talk about changes to the category development process. If there are ways to reduce the time required to develop a category, the life of GF-6 could be very limited. Category change now involves a number of organizations and can be confusing as well as slow.

It is interesting that, if you were to attend API, SAE International, ASTM, ILSAC or American Chemistry Council meetings, you would find most of the same people in attendance. Maybe we just need one big meeting with subcommittees to do their thing, and then all would vote on the final outcome. On second thought, that sounds too much like Congress!

Industry consultant Steve Swedberg has over 40 years experience in lubricants, most notably with Pennzoil and Chevron Oronite. He is a longtime member of the American Chemical Society and SAE International, where he was chairman of Technical Committee 1 on automotive engine oils. He can be reached at steveswedberg@cox.net.