API SN is an upgrade of the current API SM category, and will be identified for consumers by the API Donut trademark. It aims to address the full spectrum of engine oil viscosity grades, including those not covered under the ILSAC specification, such as SAE 10W-40. (ILSAC grades only include SAE 0W-XX, 5W- XX and 10W-30.)

API SN Resource Conserving, which will replace the current SM Energy Conserving designation, has additional requirements covering fuel economy improvement and vehicle emissions systems protection.

ILSAC GF-5 oils are identified by APIs Starburst trademark, and were developed jointly by ILSAC, representing North American and Japanese automakers, and oil and additive companies. The S-series of engine oil categories belong to API alone, and are referenced worldwide.

Although automakers have no vote on the American Petroleum Institutes categories, they had been uniformly negative over a series of meetings in recent months. Some OEMs even threatened to withdraw support for API licensed oils entirely if the SN category was not aligned to GF-5 in areas such as phosphorus content and deposit control.

On its side, API took the position that SN is intended to serve as a global industry performance standard for gasoline engine oils that permits licensing of a wide range of viscosity grades under APIs Engine Oil Licensing and Certification System. It is intended to provide some level of improved performance worldwide, including those areas where ILSAC GF-5 is not used. Unlike GF-5, its focus is engine protection, improved deposit and sludge protection, and elastomer compatibility – not fuel economy.

At stake, beyond the issue of turf, was what test regime should be used for oils to qualify for licensing SN, and how strict the limits should be. The engine and bench tests required to license ILSAC GF-5 are quite steep. Even if a GF-5 candidate oil passes every required test on its first run, the cost will top $160,000, industry sources told LubesnGreases. Thats why historically API has set its S-series test limits to be more forgiving, and waived some ILSAC tests, to help hold costs down and allow the oils to compete in global markets.

Redrawing the limits

The API Lubricants Committee completed its review and editorial revisions of the category definitions at the end of April (too late to include in last months LubesnGreases). And while the final language, test limits and definitions for API SN still do not align exactly with the ILSAC GF-5 specification, as automaker representatives had hoped, the SN Resource Conserving category was revamped to satisfy their requirements.

They [automakers] definitely didnt approve [SN], APIs engine oil licensing manager Kevin Ferrick, in Washington, D.C., confirmed last month. The OEMs commented that had there been a separate ballot item for SN Resource Conserving, they would have approved that. But for practical purposes, we didnt feel it was necessary to change the ballot and issue it again. That was enough for us, that they approved of SN Resource Conserving. It makes sense because its an exact duplicate of GF-5.

Ferrick noted that while the automakers are probably not happy with API SN in its final form, the Lubricants Committee felt strongly that oil marketers need SN to have some ability to meet what they perceive as a global need outside North America and Japan.

Here in North America, the automakers are essentially recommending GF-5, he noted. So SN Resource Conserving would give a clear signal to a consumer that theyre getting a GF-5 product. API and the Lubes Committee agreed that they will do more to make sure the message gets out, that if an OEM is using GF-5, then you need to use GF-5 – that an SN oil by itself is not going to be enough. That you then have to [use] SN Resource Conserving. But then SN is available for places where GF-5 performance isnt recommended.

One ongoing fear for automakers is that consumers will buy oils other than those which are ILSAC grades and therefore not meet all of their requirements. On the other hand, API members feel that some tests are redundant and others are excessively restrictive.

OEMs had suggested beefing up the SN requirements by including an 800 ppm phosphorus limit, requiring the TEOST 33C test for high-temperature turbocharger deposits, and testing emulsion retention in all SN oil viscosities. The revised ballot addressed each of these issues to some extent, though not across the board for all viscosity grades.

A lot of the comments we had from the automakers had to do with concerns about misapplication, Ferrick explained. There was concern SN oils could end up in their cars when they need to be GF-5 or SN with Resource Conserving.

The committee discussed that and did agree they need to do significantly more consumer education to make sure that theres not a misapplication. To this end, the Lubricants Committee agreed to add a new sentence to the SN service recommendation: Vehicle owners and operators should follow their vehicle manufacturers recommendations on engine oil viscosity and performance standard. They hope this will help ensure that the oils recommended by engine manufacturers are used, especially in newer model-year vehicles.

If at first you dont succeed …

API first tried to ballot the SN categories on Jan. 8, but that ballot was withdrawn in the face of strong auto industry opposition. The ballot was rewritten and issued again on March 31, with a very tight deadline for approval.

With the ballots in hand two weeks later, on April 16, the issue went before an Administrative Guidance Panel, in an attempt to hammer out a consensus. The recommendations that came out of there were similar to the ones found in the ballot, Ferrick noted. The 15-member Lubricants Committee worked out final definitions, editorial revisions and user language for API SN and SN Resource Conserving during an April 23 conference call to review ballot comments.

Throughout the process, representatives of the auto industry were very clear in their belief that GF-5 limits on all tests should apply to SN. They generally recognized that fuel economy is limited to the specific grades they identify for GF-5, but wanted all the bench test limits to be identical with GF-5. If the non-ILSAC oil viscosity grades do not meet all of the GF-5 limits (except fuel economy), the OEMs worried that there could be premature failures.

And even though they could not vote on the API oils, General Motors, Chrysler, Ford, Nissan, and Toyota all made extensive comments about SN and SN Resource Conserving categories.

One concern, they said, was that they saw few changes from API SM to API SN. They contended that even their latest model vehicles will very likely end up with non-ILSAC viscosity grade engine oils. If requirements such as the phosphorus maximum were not enforced across all viscosity grades, the OEMs said, their emissions systems would be vulnerable to premature failure. This would be very costly, as OEMs are required to warranty their emissions systems for 120,000 miles, under U.S. Environmental Protection Agency mandates.

More doubts to overcome

The fact that oil change intervals have significantly lengthened in recent years was also a cause for concern among the OEMs. In particular, they worry that so-called universal oils which carry both C and S category credentials (for both diesel and gasoline fueled engines) could have a serious impact on passenger car emissions systems durability. This is because C oils permit higher phosphorus content than S or GF category oils, and engine oil phosphorus is deemed a catalyst poison.

In the end, API agreed that its worth discussing whether C and S categories can continue to be combined safely – but said it was too late to include that discussion as part of the API SN ballot. It invited passenger car and diesel engine manufacturers to discuss the issue together, and bring forward a proposal on how theyd like to proceed in the future.

Ford expressed qualms about engine oil compatibility with ethanol-containing fuels such as E85, particularly in other parts of the world such as Brazil. One API Lubricants Committee member, who asked not to be identified, pointed out to LubesnGreases that Brazil has been using 100 percent ethanol for a number of years with no problems, even though the oils currently sold in Brazil fall somewhere between API SL and SM in quality.

Turbocharger protection is another source of apprehension, the automakers have said. GM, Ford and Chrysler all assert that passing the TEOST 33C high-temperature deposit test is essential to their vehicles, in order to minimize the risk of warranty claims for turbocharger coking. They wanted the TEOST 33C test to apply to all API SN grades. In the end API voted not to require this test across the board, but only for the SN Resource Conserving oils.

Automakers also expressed doubts early on about the lack of a used oil low-temperature pumpability requirement for non-ILSAC grades, and wanted SN to include the Sequence IIIGA and/or the new ROBO test. These tests are especially useful for low-temperature markets, because starters for modern automobiles are so efficient that any engine will start despite severe cold. But if the oil wont pump, the engine could starve for oil once it is running.

API responded by adding the ROBO/IIIGA requirement to all its SAE 0W-XX, 5W-XX and 10W-XX SN multigrade oils, including 5W-40 and 10W-40. However, it noted that there is no data to support the additional testing beyond those viscosity grades, so monogrades and 15-W, 20W and 25W multi-grades will not have to pass the test.

In concluding its final deliberations on April 23, the Lubricants Committee reiterated that API SN Resource Conserving matches exactly the phosphorus retention, high-temperature deposit control, low-temperature pumpability assurance and other benefits of GF-5.

API SN without Resource Conserving, on the other hand, provides improvements such as deposit and sludge protection and elastomer compatibility for regions where GF-5 is not recommended. And new language has been inserted, stressing the need for consumers to follow their owners manual recommendations.

So come Oct. 1, youll start seeing the two new category designations in the trademarked API Donut.