Why was the GMOD test dropped from GF-6?

[oil_film_movies]

The GMOD oxidation test extravaganza was recently dropped from GF-6.
Was is because Group II oils can't pass it? Its still part of the update for the dexos (here in the later half of 2017), yet we know dexos has always resulted in at least semi-syns or full syns (II/III or III) being used, no all group II oils making the dexos cut.

Maybe the Seq IIIH alone was considered to be enough for GF-6? GF-6 looks pretty tough to meet for the old group II oils one might think even without GMOD.

http://passenger.lubrizoladditives360.com/specifications/gf-6/gf-6-articles/
didn't have any explanation that I could find.

 

[Revving2Redline]

That mean we can finally get rid of conventional oils?

 

[oil_film_movies]

Originally Posted By: Marco620
That mean we can finally get rid of conventional oils?
At least the semi-syn half-dino level of performance. GM has done that now for 5 years. Group II oil car makers Ford, Nissan, Hyundai, Fiat-Chrysler, etc., may follow with GF-6 out in 2 or 3 years. I'm guessing of course, since maybe somebody can formulate an all-GroupII GF-6, just maybe.

 

[Revving2Redline]

Very interesting. Thanks for the info.

 

[wemay]

Thanks for posting! Interesting.

 

[SonofJoe]

I haven't really been following GF-6 on the basis that one could die of boredom waiting for it to become a reality.

However, in the usual way these things work, in terms of (mega expensive) engine tests, there is 'one of everything'; one oxidation test, one sludge test, one wear test, one fuel economy test and one bearing corrosion test. You can have as many lab/rig tests as you like in the spec as these tend to be cheap.

The Sequence IIIH and GMOD tests were basically competing for the same engine test 'space'. Given that these tests cost a small fortune to run, it's hard to justify (in API/ILSAC terms at least) the inclusion of two such similar tests. GM of course, as the sole controller of Dexos, can do whatever it wants and probably has absolutely no qualms about including both tests (plus a whole lot more) because GM doesn't have to pick up the tab for oil developments and seems quite happy to see the extra costs borne by the folks that buy Dexos certified oils.

Also, when looking at why GMOD got dropped, you should bear in mind that all the individual OEMs want 'their' favoured tests in the final spec. Inevitably there is a process of horse trading that goes on to ensure 'a bun for every bear'. Fiat-Chrysler probably only had the IIIH in the race, so in the interests of fairness to all OEMs, were allocated the oxidation test.

From what little I know of the Sequence IIIH test, my limited read of the test is that it will be MORE tolerant of high Noack Group IIs than the Sequence IIIG. The 'problem' with the IIIG was always that it recycled a lot of oil through the PCV system (which is why its pistons were always so grubby). This sort of acted as a brake on Noack. With the IIIH, Fiat-Chrysler have frigged things to keep the oil in the sump (some form of blow-by cooling/condensation maybe?) and out of the air intake. The test has become more of a pure oxidation test which may require more AO but will probably allow more volatile oils through.

Given the number of BITOG posts about excessive oil consumption, I can't but help thinking the IIIH is a step in the wrong direction and DOESN'T give backwards compatibility with the IIIG. But hey, what do I know...

 

[oil_film_movies]

SonofJoe, much appreciated. At these raucous GF-6 meetings, do the oil blenders argue against GF-6 becoming too tough for Group II low-tier oils? Seems like adding all these tougher requirements means the oil sellers will have to raise material costs with injections of Group III into their cheapest stuff on the shelf now.

At first I thought the dropped GMOD test was a way to get cheap formulas to pass GF-6. Maybe not exactly that as I see know. Certainly dexos adds so many tests on it does end up requiring more expensive oil.

 

[Jetronic]

But i the current oils are already knocking on the 15% Noack limit, the change from IIIG to IIIH is surely moot? They can't actually go to higher Noack basestocks.

 

[SonofJoe]

Originally Posted By: oil_film_movies
SonofJoe, much appreciated. At these raucous GF-6 meetings, do the oil blenders argue against GF-6 becoming too tough for Group II low-tier oils? Seems like adding all these tougher requirements means the oil sellers will have to raise material costs with injections of Group III into their cheapest stuff on the shelf now.

At first I thought the dropped GMOD test was a way to get cheap formulas to pass GF-6. Maybe not exactly that as I see know. Certainly dexos adds so many tests on it does end up requiring more expensive oil.



I can't honestly say I've sat at the table when these things get debated. I just used to listen when our Industry Liason guys fed back. From what I recall it's all very polite & committee-like. Votes are taken on what goes forward and what gets omitted. Obviously various parties have agendas and red lines and alliances inevitably form. The AddCo's will always vote for anything that increases additive treat rates. The oil companies support anything that gives them maximum flexibility of blending. The OEMs are always the great agents of change and they usually get everything they want, however weird.

In some ways, I think the process of spec setting is extremely narrow minded; focussed on arcane detail rather than on any coherent direction of travel. For example, I doubt in all the discussions of all the specs that have been set over the decades, not one single person has ever questioned whether a test or change was ever economically justified or was in the interests of the ordinary car driver. Likewise, I suspect that despite all the myriad improvements in engine oil over the decades, no party has ever specifically said, if we add this test and that test, we can increase OCI by x amount.

I have said many times that this industry functions solely to meet its own objectives. Your job and my job is simply to suck up whatever we're given at whatever price they think fit. Strange but sadly true...

 

[dave1251]

Originally Posted By: oil_film_movies
SonofJoe, much appreciated. At these raucous GF-6 meetings, do the oil blenders argue against GF-6 becoming too tough for Group II low-tier oils? Seems like adding all these tougher requirements means the oil sellers will have to raise material costs with injections of Group III into their cheapest stuff on the shelf now.

At first I thought the dropped GMOD test was a way to get cheap formulas to pass GF-6. Maybe not exactly that as I see know. Certainly dexos adds so many tests on it does end up requiring more expensive oil.


The cheapest stuff is already labeled "synthetic blend" with presumably group III basestocks. As a matter of fact many "synthetic blends" barley pass GF-5 NOACK of 15%. While most "conventionals" from the majors pass wtih lower NOACK percentages.