SAE to Debate Engine Oil Classification


Everywhere in the world, engine oils are sorted according to SAE J300, the 94-year-old document that governs “Engine Oil Viscosity Classification.” Now J300’s position as a bedrock of the engine oil world is being challenged. Critics say the standard rests on outmoded measurements, is unhelpful to consumers, and needs to be more flexible as technology advances.

These critics– and J300’s many proponents — will get to air their views at an SAE Open Forum next month. Depending on how that goes, says Dewey Szemenyei of Afton Chemical, the world could see changes ranging from tiny tweaks to full-blown revisions in this key standard.

First issued in 1911, SAE J300 began as a simple system that arrayed engine oils according to kinematic viscosity, in a straightforward fashion. More measurements were added over the years, to ensure cold cranking, pumpability, high-temperature viscosity, and ability to stand up to shearing. From a single numeric ranking, the system grew to include “W” grades for winter driving and multigrade engine oils, leading to today’s complicated roster of oils including SAE 5W-20, 10W-30, 15W-40, SAE 30, etc.

Which is where the conflicts begin. Critics charge that J300 fails to meet consumers’ need for easy-to-understand information on fuel economy and cold-weather performance. Oil marketers feel boxed in by the system, saying J300 doesn’t recognize innovation and should help promote the fuel-economy advances that are possible with high viscosity index base stocks. Heavy-duty engine builders have expressed dissatisfaction with some of its definitions, saying they need additional grades to assure they get the appropriate wear protection at high temperatures.

Although he declines to take sides in the debate, Szemenyei feels the time is ripe for airing it out. As chairman of SAE International’s Technical Committee 1 on Engine Oils, he recently asked the group’s Engine Oil Viscosity Classification Task Force to take a closer look at J300: “What is it? What should it be? Who are its major customers? Should it stay like it is, or undergo a major transformation?”

To address those questions, the task force is sponsoring an Open Forum on Tuesday, Oct. 25 in San Antonio, Texas. The goal, its organizers explain, is to open up J300 to scrutiny, to see what can be improved — or even decide that the standard is fine and should be left alone.

At the moment, the standard seems to be working adequately for most of its stakeholders — automakers, engine builders, oil and additive companies, government agencies and more — but not for individual consumers, points out Andrew Jackson of ExxonMobil, who chairs the SAE task force looking at J300. Some drivers, he says, switch to inappropriate grades despite the recommendations in their owners manuals, out of habit or ignorance or convenience. The standard’s alpha-numeric nomenclature — SAE 5W-30, 15W-40, 30, etc. — while meaningful to manufacturers and blenders, is baffling to many consumers. Drivers are especially distrustful of low-viscosity grades such as 0W and 5W, not realizing that these oils provide good wear protection and can also boost fuel economy.

Task force member Mike Covitch of Lubrizol points to another issue. “There’s a concern,” he says, “that formulating certain popular viscosity grades will become constrained with the availability of high viscosity index base fluids, especially Gas-to-Liquid base oils. These are not a presence in the marketplace now, but they will be sometime around 2008 to 2010, and we’re seeing some of that now with API Group III base stocks.”

Under the current viscosity classification system, he points out, the cold-cranking viscosity measurement includes a floor for each W grade, such as 5W-30 or 10W-30. Formulators can use high viscosity index base stocks to get both their viscosity and volatility in line — but then their highly sophisticated fluid may drop out of grade, and slip down to the next W level, such as the tough-to-sell 0W.

Another longstanding criticism of the system is that it uses kinematic viscosity at 100 degrees C — a simple gravity-based measurement — to differentiate between viscosity grades. That’s convenient, but it is of no value in terms of evaluating wear protection under the dynamic conditions that exist in an engine, Covitch and others say. Durability is what matters.

At last week’s World Tribology Congress in Washington, D.C., Ted Selby of Savant was among those arguing for giving greater emphasis to the dynamic viscosity measurements rather than the old kinematic viscosity gauge. “Low-shear-rate viscometry is an anachronism,” he stated, asking, “Why, for this most important property of engine oil, do we still classify engine oils by low-shear viscometric limits and archaic alpha-numeric terminology — which is know to seriously impede the consumer’s rational choice of engine oils?”

There are also those who think very little should be done to J300, including Bob Olree of General Motors. “In our case, I don’t see a big need to change J300,” he comments. “We recommend 5W-30 engine oils for almost all our vehicles, and don’t use the super-low viscosity grades much, except we do recommend 0W-30 for some very low-temperature applications.”

Nevertheless, he continued, “I still think we need to look at [J300] and am very happy we’ll have an open forum. I’ll be interested in hearing what others have to say — and maybe they’ll show me why change is needed.”

If change is needed, Andy Jackson noted, work on any rewrite must begin soon. “If we wait, by the time the next generations of passenger car and heavy-duty engine oils are being developed, we may not be able to move fast enough.”

SAE’s Open Forum on J300 will be held at the group’s Powertrain and Fluid Systems Conference in San Antonio, from 9:45 a.m. to noon on Tuesday, Oct. 25. The forum is open to all stakeholders and conference attenders. Many presenters are already lined up, although some 10-minute slots may still be open for those who want to share their insights and views, indicates Szemenyei. Those interested in presenting are encouraged to e-mail or fax a proposed title and brief abstract to the task force’s Jackson at Fax: (908) 730-3031.

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