Finished Lubricants

Need To Know


When you ask an industry insider what a full synthetic motor oil is, you typically hear that its a product made with API Group III base oil, polyalphaolefin, possibly some API Group V stocks such as esters, or a blend of these fluids, as well as additive packages optimized for use in such stocks.

Most importantly, they say, synthetics will outperform conventional motor oils in a number of areas, including resistance to oxidation and low- and high-temperature performance, among others.

But as discussed in my column last month, no test can prove that a finished oil is made with Group III base stocks, and there are no rules, regulations, measures or metrics that define what is and is not a fully formulated synthetic motor oil.

As a result, synthetic is not a quantifiable term for motor oils; instead, it has become a marketing term. Herein lies the paradox and reason for concern: If its only a marketing term, what stops a company from putting the words full synthetic on a label of conventional motor oil and enjoying a significant premium by selling it as such?

If product performance is the answer, then the question remains: What performance measures separate full synthetic from conventional, or for that matter synthetic blends? Since there are no official measures defining the performance of synthetic motor oil, the product performance explanation reverts back to a marketing term.

Technically speaking, however, although there are no tests to prove a motor oil is made from Group III, there are measurable and meaningful differences in performance that can be examined to determine if a product has the performance characteristics expected when Group III is used. Further, for some viscosity grades, a Group III must be used to meet requirements for API SN/SN Plus and other industry specifications.

As an example, it would be highly unlikely that an SAE 0W-20 oil would meet the viscometrics, Noack volatility, high-temperature high-shear viscosity and other performance parameters required to meet the latest API or Dexos specifications with the use of Group I and Group II base oils alone. But it can be made using a Group II+ with some high viscosity index Group III, if a company invests in this type of approval and costs can be lowered.

So, from that perspective, there are quantifiable boundaries that can be helpful in separating a conventional motor oil from synthetic for some grades and specifications. But thats not necessarily the case for SAE 5W-30 oils, which currently account for close to 40 percent of United States passenger car motor oil demand.

Whereas some Group III may be required in these grades as a trimmer stock or correction fluid, they can be made to meet API SN/SN Plus with a blend of Group II and Group II+, or even Group II+ alone if the V.I. is high enough to avoid issues with cold cranking simulator performance and Noack volatility.

With Group III costing some 25 percent and 15 percent more than Group II and II+, respectively, there are cost and therefore competitive advantages in using as little Group III as possible to meet the minimum requirements of API SN/SN Plus. This is not to say all, or even most, blenders do this. Instead, it points to the reason why some can and might, and the width of the window in the quality-performance continuum for synthetic motor oil.

And although there is currently little to nothing to stop a marketer from labeling an SAE 5W-30 with only Group II and additives a synthetic, its performance and price would be well under that of an oil made with Group III and even further below one made with PAO.

Still, there are clear and measurable lines that separate conventional motor oil from synthetic in the market place. The major line is price, which amounts to an average spread of roughly $40 between a conventional and synthetic oil change.

Are consumers really getting more carrots with their meal when they pay more for synthetics? In most cases they are, but the quality and number of carrots can be significantly different. Because of this, many marketers say the cachet and value synthetics bring is eroding as some are finding it necessary to move price or quality down in response to price pressure and consumer perceptions that all synthetics are the same.

Although its clear that some are working to address this issue by offering premium tier synthetics, premium is also a marketing term that we sometimes see on unremarkable products. Because of this, they too could be pulled down the quality continuum by price pressures.

In the absence of an industry definition of what the terms synthetic and premium synthetic mean, its likely OEMs will have more reasons to create their own specifications and approval systems. These OEM specifications will indirectly but increasingly define what the terms mean by favoring use of base oils and additives that meet their rigorous requirements, rather than those of the API. Further, they will drive greater use of genuine oil and limit opportunities for others in the PCMO space.

With that, there is little wonder why some are solidly against defining what the terms mean, where others are pushing to see it happen.

Tom Glenn is president of the consulting firm Petro­leum Trends International, the Petroleum Quality Institute of America, and Jobbers World newsletter. Phone: (732) 494-0405. Email:

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