API Seeks Answers for SM & GF-4

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May 18, 2003
SE Michigan
API Seeks Answers for SM
By David McFall

After receiving this week's update from Lube N Greases, I wanted to make sure to share this story with LubeTalk subscribers. This is a very good article about the new ratings for EGR engines and more…Thanks David.

With the new GF-4 gasoline engine oil upgrade now virtually certain to be approved later this year, industry wide interest has turned sharply to the details of API SM, the companion Service Category which will parallel GF-4 and replace the current API SL engine oil category.

The issues surrounding SM are more numerous and complex than they were for earlier categories. And as a recent meeting shows, backward compatibility of the new oils remains a nagging concern.

The GF-4 specification was developed by the stand-alone ILSAC/Oil Committee, composed of auto and oil industry representatives, and its scope is primarily North America and Japan. Only low-viscosity grades such as 5W-20, 5W-30 and 10W-30, which automakers recommend in their manuals, can meet GF-4's fuel economy requirements.

By contrast, Service Categories are under the full control and authority of the American Petroleum Institute; its Lubricants Committee has sole responsibility for development and approval of SM. API's Service Categories, including SM, have a worldwide reach and include all viscosity grades - the ones mentioned above, plus popular multigrade weights such as 10W-40 and 20W-50, and also monograde engine oils.

On Oct. 2, API's Lubricants Committee met by closed conference call to consider a proposal from Ciba Specialty Chemicals Co. regarding the phosphorus limit for API SM. Because phosphorus is detrimental to emissions systems, the ILSAC GF-4 specification limits the phosphorus content of engine oils to 0.08 percent mass, but Ciba's proposal was to cap the SM phosphorus limit at 0.10 percent for all grades.

Ciba's Vince Livoti told Lube Report afterward, "Most of the cars on the road when SM comes out in 2004 will be post-1996 [models], and these cars and their emissions systems were all designed to run on 0.10 percent phosphorus oils. That was the phosphorus level for GF-2, which became effective in 1996, and continues through GF-3, the current quality level. So with all 'S' category viscosity grades, not just ILSAC oils, capped at the 0.10 percent level, the engines and emissions systems for all 1996 through 2003 model-year cars would be protected."

As for emissions systems for the 2004 model year and beyond, which GF-4's 0.08 percent phosphorus limit aims to protect, Livoti reasoned, "Even if all SM oils would be permitted to have a phosphorus level of 0.10 percent, if an oil marketer was going to display the [api] starburst as well as the donut, the phosphorus level would have to be at or below the 0.08 percent level to meet GF-4 limits, thereby protecting late-model cars. So both old and new engines and emissions systems would be protected across the board." The proposal, he added, "has the advantage of simplicity and we've tried to keep it that way in the customer's interest."

The Lubricants Committee disapproved Ciba's "simple" proposal. During the meeting, however, Valvoline presented another proposal - one which added complexity. It called for splitting the lower part of API's donut symbol, so that in addition to being able to claim the "Energy Conserving" label in the bottom half of the donut, marketers who met the 0.08 percent phosphorus limit could make another claim such as "Emissions Compatible" or "Resource Conserving," with the exact label to be formalized later.

The Lubricants Committee made no decision on this proposal.

Oddly, API had closed the entire Oct. 2 session to the public. In the development of standards, API subscribes to the requirements of the American National Standards Institute, including the core principle of "due process" and open meetings with reasonable and convenient access available to everyone with an interest in any standard being considered. That standard was adhered to for all meetings of the ILSAC/Oil group that developed GF-4, too.

Yet, despite protests by Lubes'n'Greases magazine, API declared that Ciba's SM proposal was a "policy" issue and not a standards issue subject to ANSI due-process requirements; it placed the discussion of this issue in a "business" session and closed the conference call to outsiders.

In a separate communication to Lubes'n'Greases magazine, Valvoline's Fran Lockwood, chairman of API's Lubricants Committee, stated, "SM will get a thorough public development process beginning this fall."

The issue of backward compatibility has been foremost in many of the technical discussions regarding the new GF-4 specification and the companion SM category. In the spring, for example, Ciba suggested to API that two API Service Categories, SM and SN, be created to parallel GF-4: One category would provide oil marketers flexibility with respect to emissions systems compatibility limits, the other would more closely resemble GF-4 with the exception of fuel economy requirements. This way, both engines and emissions systems should be protected by using API-licensed oils.

At the time, Ciba noted that market dynamics in regions outside the United States make it impractical to restrict the phosphorus content of oils sold in those regions. In addition, oils meant for use in older cars or mixed fleets also present hurdles for phosphorus-restricted S category oils.

Ciba's proposal of two companion categories would have been a clear break with past practice, where only a single companion to a GF category had ever been considered or approved. API's Lubricants Committee, meeting in open session in May, did not accept this proposal either.

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The auto makers sure want to throw the their problems onto the laps of the oil companies to remidy.
How about the fix being the auto makers increasing the sump capacities of their engines, add oil coolers, and/or divorce the "One SAE grade for all seasons" mentality?
To pass the wear tests using .08 phos (zddp) will mean that they will probably have to find something as good (moly or calcium) or maybe start putting esters and/or PAO in dino oils. Prices will go up, but I don't think as much as they have been marked up in the "specialty market" such as high mileage oils.

A car that is an oil burner will probably clog the cat even if the oil had .02 phosphorous! So I agree, they should design the engines better to not burn the oil or cook it so that it doesnt hit the cat!
You may have hit the nail on the head.
The switch to 5W20 has raised the oil consumption issue to the point where some of the additives may harm the emission control hardware.
It has always been my opinion that if an engine does not consume oil, then the additive package and its potential affect to the emission controls is a non-issue.
What do the rest of you guys think?
Why not just enforce the use of less volatile oil, which would address the consumtion issue?
The Ford 153H test does exactly that.
Then the problem associated with less volitile base lubes arise, such as thinning due to shear.
With oils blended from, or including low boilers, the engine oils stay in grade longer because the thinning from shearing is balanced by thickening from the volitiles boiling off.
Quite often synthetic lubricants, whether blended from PAOs or group IIIs are unfairly slammed because they thin out of grade faster than some other engine oil examples.
What is really happening is that the oil is not thinkening from oxidation, comtaminant load, or boil-off.
I think that M-1 0W40 has been mentioned as one engine oil that thins out of grade "quite nicely".
That would be Mobil's reward for using a very high flashpoint, oxidation resistant, <1% NOAK base lube in their blend.
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