By Steve Swedberg

In our August and September issues, columnist Tom Glenn raised the topic of synthetics and their place in the market. Tom did a good job of spelling out some of the current issues surrounding these products. He even asked for a working definition of synthetics that would assist marketers and consumers to make the most informed decisions about their motor oil purchases.

This request isnt a new one. It was debated at length in the early-to-mid 1990s, while I was chairman of SAE Technical Committee 1 on engine oils, part of its Fuels and Lubricants Division.

At the time, SAE was the place where all the discussions regarding what constitutes a synthetic were going on. The driver for the discussions was a regular update to the SAE Information Document, J357, Physical and Chemical Properties of Engine Oils. SAE J357 is a very useful document since it covers most of the basics of engine oil composition as well as the tests most often used to evaluate new and used oils.

Under SAE protocols, documents are reviewed periodically (every five years at least) and updated when necessary to reflect the latest test techniques or industry knowledge on a subject. And in the early 1990s, J357 was on the docket to be reviewed and updated.

One of the desires of SAE Technical Committee 1 was that J357 be more complete, especially with regard to base oil and additive descriptions. That meant expanding the sections on base stocks and additives with the intention of educating those who read and referenced the document. The American Petroleum Institute had not yet established the Base Oil Groups that we are all familiar with today; those came in 1993.

Bob Cain of Lubrizol was the leader of the task force charged with the rewrite of J357. Little did he or I know that the subject of synthetics would take several years to resolve, and then only temporarily. Bob presented his task groups recommendations, and we had them mailed out to the membership of TC-1 for review. The response was swift in coming and revolved around the definition of synthetic.

Bobs group had defined synthetic as follows: Certain chemical compounds have been found to be suitable as base stocks for engine oil. These are referred to as synthetic lubricants and are defined as having been produced by chemical synthesis. That seemed pretty straightforward since the term synthetic is generally defined as relating to or involving synthesis, and something resulting from synthesis rather than occurring naturally, according to the Merriam-Webster dictionary.

What came back were strong responses from BP and Shell. Both were just getting what came to be known as API Group III base stocks off the ground and were touting their extra-high viscosity index (120 and greater), high saturates content and virtually zero sulfur. This was performance territory that polyalphaolefins had previously dominated.

The first round in the discussion/floor fight took place in 1993, I recall, at the SAE annual meeting in Detroit. Fuels and Lubricants sessions were held in Dearborn, Mich., at the Hyatt Regency. Over 200 crowded into one of its large ballrooms for the TC-1 meeting.

After Bob Cain made the task force presentation, the players in this drama had their say. Mobil Chemical (now ExxonMobil Chemical) argued intensely that synthetic is as defined in the dictionary, and only something that is synthesized can be labeled as such. Of course this stance came from the fact that it made and sold PAO base stocks and Mobil1 synthetic engine oil. Fellow PAO producer Chevron Chemical (now Chevron Phillips Chemical) supported the Mobil position. So did Castrol.

Shell also teed up its position. Basically, it said, its XHVI base stocks should qualify as synthetics. Shells argument hinged on the fact that these base stock molecules could be created either by polymerizing wax (a synthesis process) or by severely hydroprocessing crude; either way, the end result was chemically similar. BP supported that position.

The argument raged back and forth in the following years. Finally, SAE J357-FEB95 was issued with a detailed breakdown of the various synthetic base stock types, shown on page 10. Its quite a comprehensive list although it lacks performance parameters for comparing the various stocks.

Yet, just over one year later in 1996, J357 was reissued without any references to synthetics. The Shell/BP argument had won after all. Yet for some time there remained an assumption that, even though synthetic definitions were gone, there was some unspoken rule within the industry that synthetic engine oils were based on PAO, usually blended with some ester to solubilize additives, aid in seal swell and enhance lubricity. (To be honest, I dont remember any unwritten rule – but no one was really looking at very-high V.I. base stocks for anything other than top-quality motor oils.)

The last nail in the coffin was Mobils challenge to Castrols use of the term synthetic on its Castrol Syntec engine oils, which by then had switched from PAO to Group III base oils. Mobil took its case to the National Advertising Division of the Council of Better Business Bureaus in 1999, and as we all know, it lost. The NAD concluded that syntheticis only a marketing term. This ruling gave API Group III (as it was by now known) the unofficial green light to compete on the same track as PAO and other synthetics. From that point forward, Group III base stocks became the core for synthetic engine oil products.

The next level of the definitions game became, how synthetic is synthetic? Tom Glenn mentioned that there are products out there that claim to be synthetic, even though they may use such highly diluted additives that their actual Group III or PAO content falls below 50 percent. The rest is the additive package, diluent oils (likely Group I and Group II), and V.I. improvers.

We shouldnt be surprised. This is an old trick that was perfected long ago by the Pennsylvania Grade lubricant marketers. When supplies of Penn Grade base oils of the proper viscosity began to run short of demand, engine oil marketers began to order more highly diluted additive packages to maintain the illusion that the oils were 100% Penn Grade. It never got to the point where the Penn Grade content dropped below 50 percent – but it did get down to the 70 to 75 percent level before the Penn Grade claim was quietly dropped by Quaker State, Pennzoil and most others.

The driver for this action was the change in viscosity grades versus available base stock cuts. Penn Grade base oil refineries make a larger share of bright stock, which is fine for making SAE 30 motor oils. However, multigrades beginning with SAE 10W-30 needed a much lighter base oil, and thats where the problems originated. So the bottom line regarding the dilute additive trick is that it happens, and it will never be easy to regulate.

The question about semi-synthetics is even more interesting. What defines a semi-synthetic blend? Theres even debate about whether the proper term is semi-synthetic, synthetic blend or partial synthetic.

I suggest that one way to look at it is to use Annex E of API Document 1509, which governs base oil interchange in engine oil formulations, as a guide. A motor oils qualification for API licensing is based on a specific composition of base oils and additives. If you change the base oil component in the formulation, Annex E may require you to rerun some tests.

Now suppose you want to turn your fighting-grade motor oil, made with Group I and or Group II base stocks, into a synthetic blend with the addition of some Group III. According to guidelines from Annex E, up to 30 percent of either Group III or Group IV could be included and would not require you to run any tests except a Sequence VID fuel economy test – and that only if the viscosity of the finished oil is greater than the original product of the same viscosity grade. That says to me that almost anyone can create a synthetic blend with less than 30 percent synthetic base stock and not even test it.

Since you dont need to test a base stock interchange of up to 30 percent, maybe that should be the starting point for synthetic blends. I suggest that 30 percent synthetic content becomes the demarcation line, the bare minimum, for claiming a synthetic blend designation; anything above that means that engine test work has been done to demonstrate performance.

Now for the flip side. How do you define a synthetic? It seems logical that the base oil component should be 100 percent synthetic (Group III, IV and/or V). However, additive packages do get dissolved into base oil for ease of handling and in some cases processing. In reality then, synthetic motor oil has conventional oil in it.

If for some reason you want to use some Group I and/or Group II base oil in your all-synthetic motor oil, you would need to run tests if the Group I/Group II level was greater than 10 percent of the base stock. Given that low level, it wouldnt be very advantageous to dilute your synthetic base oil.

So there it is. Its well accepted that synthetic lubricants may include Group III base stocks made via hydroisomerized refining techniques, the new gas-to-liquids base stocks made from the Fischer-Tropsch process, as well as the arsenal of chemically synthesized products listed in SAE J357-FEB95.

That leaves individual oil marketers to grapple with how to define the synthetic oil lines they offer. For synthetic blends, should they decide on a 30 percent minimum content, or something else? Could it be that someone out there will decide – or already has – that just a little bit is enough?

For full synthetics, the question is whether using highly dilute additives results in a legitimate product. Will blenders play it fast and loose? Maybe Sir Walter Scott had it right when he said, Oh! What a tangled web we weave when first we practice to deceive!

Industry consultant Steve Swedberg has over 40 years experience in lubricants, most notably with Pennzoil and Chevron Oronite. He is a longtime member of the American Chemical Society and SAE International, where he was chairman of Technical Committee 1 on automotive engine oils. He can be reached at steveswedberg@cox.net.