Okay, now you know that Ive gone around the bend, mixing motor oil and music. Nothing could be further from the truth. The oil industry is in a goodbye mood right now; its looking at deleting a number of engine oil categories that use older engine tests.

In the American Petroleum Institutes Engine Oil Licensing and Certification System (API 1509), a category can be active as long as the tests used to define it are available or if a correlation has been established between an existing test and an obsolete test so that performance can be verified.

Heres an example of the practice as outlined by APIs Category Life Optimization Group. It is necessary to correlate the Sequence IIIF and Sequence IIIG-which measure an oils high-temperature properties such as resistance to thickening, varnish formation and wear-to the newer Sequence IIIH, since both the IIIF and IIIG are no longer available. The Sequence IIIF was run as part of API gasoline categories SJ and SL as well as heavy-duty diesel categories CH-4, CI-4 and CJ-4. The Sequence IIIG was run as part of API categories from SJ forward, as well as all current heavy-duty categories from CH-4 through CJ-4.

Ive pointed out before that the differences in test conditions and hardware make it hard for me to believe that the latest version of a sequence test really predicts performance in an earlier version. Its probably not a critical concern, but nevertheless gets my head spinning.

Theres another aspect of the API system that causes me some concern: backwards compatibility. Using new tests to stand in for older tests is one thing, but saying that the newest category is suitable for older engines is a bit of a stretch. The classic concern is the flat tappet cam design in older engines versus roller follower cam design in newer engines.

The question here is phosphorus content with zinc as the surrogate. Flat tappets require more phosphorus for wear protection, while roller followers dont need as much. There are those who say that 0.08 percent by weight of phosphorus is enough for flat tappets, but engine builders want 0.12 percent. Guess what? The latest API SN category has 0.08 percent phosphorus as a maximum. In fact, you can go all the way back to API SH before you can find 0.12 percent phosphorus.

I should clarify that the phosphorus limits are strictly speaking only for SAE 0W-XX, SAE 5W-XX and SAE 10W-30. Other viscosity grades are not limited for phosphorus content. Practically speaking, however, oil blenders dont want to have multiple additive packages for their main engine oil lines, so other viscosity grades use the same packages.

Now we come to the real crux of the matter: Should we keep API categories that are covered by backwards compatibility or CLOG? What are the arguments in favor and against?

Lets start with the case for older heavy-duty engine oil categories. The EOLCS is designed for vehicles in the North American market but is utilized in many other parts of the world. Vehicles on the African or South American continent could be of an age where API CD is specified. While the concept of backwards compatibility would say that the most recent heavy-duty category (API CK-4) would be suitable, there is a cost penalty that might not be acceptable to the consumer. In addition, there are additive differences between the two that are important. A quick look at comparisons between some API CD, CH-4 and CK-4 properties is instructive here. (See table above.)

As you can see, API CD and CH-4 call for more sulfated ash and phosphorus and a higher total base number because it was designed for then-common diesel fuel with around 1 percent sulfur content. API CK-4 is specifically designed for ultra-low-sulfur diesel fuel at 15 parts per million sulfur maximum. Some areas of the world are still running on higher sulfur diesel fuel, which means that extra ash and higher TBN are desirable.

Ive seen heavy-duty trucks, especially off-road, that have engines that still require these higher ash and TBN oils. There are ore haulers in some of the open pit mines in my neck of the woods in Arizona that could be over 20 years old. Theyre able to operate on API CK-4 only because of the fuel sulfur levels available here in North America. It might be tougher to find low sulfur fuels in Chile, for example.

You might be interested to know that globally, obsolete API categories account for about 50 percent of heavy-duty engine oil sales, according to Kline & Co. Some of that is simply mislabeling or misinterpretation of the label. However, there is a real need for these oils. Do we cancel the category and let backwards compatibility cover it, or do we keep the category alive?

Maintaining an engine oil category isnt an easy feat. The primary reason standards have gone obsolete is the availability of engine parts to run the tests. Earlier categories (CF-2, CF-4 and CG-4) died because engine parts for the required tests ran out. Thats what kills category longevity. It is also where CLOG comes into play. If performance according to the original category limits can be preserved using available engine tests that are recalibrated for older limits, we have a winner.

Using a current test to infer performance in a former test for an older category is really mind-blowing! Its sort of like taking your new flat screen, 55-inch television designed for cable and Wi-Fi and retuning it to receive black-and-white display using rabbit ears and tin foil. That paints quite a picture for me. CLOG is the industry equivalent of doing just that.

And what about chemistry? It may be that CLOGs backwards comparison works with additives being used now, but new oils that will be run in new tests will likely have somewhat different chemistry. It could be as simple as changing the treat rate, but it might require a booster of some sort. If you want higher TBN to meet an older specification, for example, you have to add something, usually detergent.

I can tell you from experience that blending operations dont like to blend lots of different formulations. Back in my Pennzoil days, we had a product simply called Pennzoil Motor Oil. It was an API SC oil when we were blending API SF and SG engine oils. There was a loyal following of the old oil and sales were upwards of 250,000 gallons a year. However, it used a separate additive package from our main Pennzoil line called Z-7. We tried to cancel it; not good. We tried to raise the price to kill demand; no-go there either. Finally, we simply rebranded the Z-7 product and sold it at Z-7 prices. Everyone was happy.

Using a booster to create a new product is also not the best choice, since it may be forgotten in the manufacturing process. Quality inspection will most likely pick it up, but it will require re-blending, which adds cost to operations. The conclusion, then, is that meeting old specifications with new oils can be really tricky.

I havent mentioned light-duty diesel engine oils here, since the issues are the same for the most part. Again, phosphorus and cam design are the main problem. There may be a market for specialty, high-zinc engine oil formulations. However, there are labeling issues in some markets. (California?) Right now, folks with flat tappet engines are buying heavy-duty engine oils where the phosphorus levels are more in line with their needs. The only issue with that practice is finding the right viscosity grade.

Proliferation of brands is always a problem for oil marketers. If the volume of sales isnt significant, it becomes a problem figuring out where and how to market products. Specialized applications (classic car oil, off-road vehicles, etc.) mean shelf space in retail outlets. Most stores will give an oil marketer only so many shelf keeping units, so choosing the proper combination of oils adds to the fun.

It is tough to say goodbye to old oil specifications, and the perfect song to cap it off is Dont You Forget About Me by Simple Minds (that could be me)!

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, ASTM International and SAE International, where he was chairman of Technical Committee 1 on automotive engine oils. He can be reached at steveswedberg@cox.net.

Dick Kabel

Richard Dick Kabel, age 85, died July 29. A Detroit native, he spent 32 years at General Motors Research Laboratories and was one of the key figures in the development of the ILSAC passenger car motor oil standard. He is survived by his wife Lois Kabel, children Keith Kabel and Kathleen Kania, and extended family.

I and so many others who knew him remembered his grin and jaunty swagger. There were times when the grin was replaced by a scowl, since he did not suffer fools. He would demand corrections of any omissions or errors. His quest for truth and accuracy was consistent. He would ease up if he found that the mistakes were honest ones. In those cases, he would help with information and background to aid in getting the right answer, without criticism. I know because that was what he did for me.

Some say that Dick could be called the godfather of ILSAC. Mike MacMillan, who replaced Dick after his retirement in 1987 as head of the Engine Oil Group within the Fuels and Lubricants Department at General Motors Research Laboratories, recalledthat Dick was dissatisfied with the oil approval system then in use, which had originated in the late 1960s and included standards from the Society of Automotive Engineers, APIandASTM International. Together, Dick and Mike developed the framework of a new system that would ultimately become the International Lubricants Standardization and Advisory Committee.

Mike notes that SAE Paper No. 2009-01-2664 tells the story but without acknowledging Dick, since he had retired by then. It was his vision that an ILSAC-type system be created, and we have him to thank (or maybe some would say blame!) that it was.

Dick was held in high regard inside automotive circles by both colleagues and competitors. People trusted him to keep his word and readily followed him because he was a natural leader. He truly was a giant.

-Steve Swedberg