An alliance of international auto manufacturers says it has concrete evidence that API category SA engine oils — long obsolete but still widely sold — are “likely to cause serious damage” and lead to increased emissions if used in engines built since the 1940s. And now it wants the American Petroleum Institute, SAE International and other lubricant industry organizations to help educate consumers not to use such products, which typically lack engine-protecting additives.
The evidence of the harm caused by using such oil is documented in a recent report from the Alliance of Automobile Manufacturers, whose member companies include BMW, Ford, DaimlerChrysler, General Motors, Mazda, Mitsubishi, Porsche, Toyota and Volkswagen. Using industry-accepted engine sequence tests, the automakers evaluated an SA oil’s effect on engine wear, sludge and deposits — and found it detrimental in every case.
The Alliance report, “Impact of Low Quality Oils on Engine Wear and Sludge Deposits; A Comparison of API SA and API SL (ILSAC GF-3) Engine Oils,” dated Nov. 8, compared the obsolete API SA oil with an oil meeting API Service Category SL/ILSAC GF-3, the most current at the time of testing. (The newest generation oil, SM and GF-4, began entering commercial service after mid-2004.)
The SA oil used in the study was purchased in San Antonio at a national chain auto-parts store. “This oil is readily available in many areas of the country,” the study pointed out. The SL oil used for comparison was a”conventional mineral oil certified to meet all API SL engine oil requirements, including those for low-temperature wear, deposits and sludge.” Tests were conducted in the fourth quarter of 2003 at an independent testing laboratory. The oils were put through twostandard tests: the ASTM Sequence IVA, a low-temperature valvetrain wear test and the Sequence VG test for sludge/deposits.
General Motors’ Robert Stockwell, who was involved in the study, pointed out some of the results to Lube Report, such as filter clogging with the SA oil (see photos below). “When the pickup tube plugs, oil starvation will occur on startup and the engine will be destroyed,” he explained. “Further, the extreme scuffing indicated on five camshaft lobes in the SA test indicate that the life of this engine would be short, regardless of the oil change interval.”
Normally, a Sequence VG engine test runs for 216 hours, but the laboratory’s test engineer stopped the Sequence VG test on the SA oil after only 168 hours, Stockwell added. At that point,the obsolete oil hadclearly failed. (The test lab was aware of the quality level of the SA oil; the SL oil was tested blind.) Intermediate inspections of the valve decks, rocker arm covers and camshaft baffles with the SA oil showed sludge deposits at 144 hours, and at 168 hours the kinematic viscosity had increased as well.
Obsolete oils continue to hold a sizable share of the U.S. engine oil aftermarket, and are widely sold in discount stores, convenience stores, mass merchandisers and other retail outlets, particularly inlower-income neighborhoods and rural areas. Although the marketers of obsolete oils defend the practice, arguing that the products offer simple, inexpensive lubrication, the oils do not address wear, sludge, deposits, corrosion and other problems of concern to automakers since the 1940s. SA oils are the types of oils sold in the 1930s; the category was defined retroactively and already considered obsolete when API first set up its engine oil licensing program in the 1960s.
In 2002, Lubes’n’Greases magazine calculated that as much as 20 percent of the passenger car engine oil sold in the aftermarket in the United States continues to be obsolete and unsupported by any performance tests, including SA and SB oils that contain no additives at all. Other obsolete categories include SC through SH for passenger car engines, and categories CA through CE on the diesel engine side.
With the proof of damage from SA oils on the table, the Alliance wants the lubricants industry now to take action, beginning with educating consumers. “The Alliance has asked API, the Independent Lubricant Manufacturers Association, Automotive Oil Change Association, NADA and other organizations whose members sell motor oil or interface with the public on lubricant quality issues, to help publicize this story,” Alliance staffer Ellen Shapiro told Lube Report. “In addition, the Alliance plans to post the study on its web site and discuss the issue with state regulatory officials.”
Actions at the state level could include new prohibitions, enhanced enforcement, new labeling requirements, and store shelf notices, the Alliance suggested.
At API, “some Lubricants Committee members had positive reactions to the presentation,” a spokeswoman said. “We will wait for the study to be posted on the Alliance website to determine what we can do to complement the Alliance’s promotion of its presentation.” ILMA went even further, and posted the Alliance’s 12-page presentation on its website last week.