With all the dust and feathers having settled around the new heavy-duty engine oil categories – earlier known as PC-11 and now officially called API CK-4 and FA-4 – its time for a look at the progress on the light-duty oil upgrade thats underway. ILSAC GF-6 is moving ahead at speeds that Norm Hunstad, formerly of General Motors Research, referred to as sub-glacial.
Both PC-11 and GF-6 were proposed at about the same time, but PC-11 crossed the finished line in February and is set for introduction on Dec. 1. Meantime, GF-6 wont see daylight until April 2018, or maybe months later, some warn. Why is it taking so long?
First, a refresher on why were here. These new light-duty and heavy-duty engine oil categories were targeted for introduction in time for the model-year 2017 vehicles. This was in response to some significantly more stringent federal fuel economy and emissions regulations scheduled to take effect for 2017.
The process for developing and introducing a new category is the same, whether for passenger cars and light trucks (the API S and ILSAC GF series of categories) or for heavy duty diesels (API C series). First, and not a surprise, comes the question, Do we need this new oil? Anyone can offer reasons for a new category, but usually its the original equipment manufacturers. After all, they are the ones on the line for warranty claims and/or compliance with federal mandates.
Having determined that a need exists, the industry has to determine what changes in existing test limits will define the new oils performance. Plus, new tests need to be developed. From there it becomes a matter of developing the test procedure, followed by establishing passing limits and ultimately introducing the new oil. There are a lot of bumps in the road to revising an existing test or creating a new one. Reference oils need to be developed, precision matrices run, and so on. One of the major issues is funding.
For the new heavy-duty oils, the main performance issues were how to achieve better fuel economy, which was addressed by creating a lower-viscosity category, now known as API FA-4; and how to show the oils would be better at resisting oxidation and aeration, which meant creating two new engine tests (the Volvo T-13 and the Caterpillar Oil Aeration Test). Not easy, but all within the normal scope of industry upgrades. The work was completed and approved by all governing bodies, and the American Petroleum Institute will allow licensed oils to display the new categories on Dec. 1, 2016.
GF-6 is quite another story. Scott Lindholm of Shell, who serves as chairman of both the API Lubricants Group and the Automotive-Oil Advisory Panel, says thats due to the number of new engine tests as well as difficulties in getting their precision matrices run and those data analyzed. It now appears that first-license date could slip to second-quarter 2018.
The process of validating any test, especially a new one, begins by selecting a reference oil (or oils) to show how well the test can measure performance. This requires an additive system be selected, agreed on and reference oils blended. However, that cant be done until the test and procedure have been tested out to make sure they measure the desired parameters; the reference oils then will demonstrate separation of results to establish passing and failing values.
Referencing is important, since no engine test can run over and over on the same engine build. Eventually, a rebuild must be done of the engines essential parts. The only way you can tell if the rebuild will give satisfactory results is by running a reference oil to see if it gives results in line with those of the original build.
Once the procedure, limits and reference oils are established, a precision matrix can begin. The matrix is run on two or more reference oils in several test laboratories with multiple engine stands. The purpose here is to be sure that test results are comparable, regardless of engine stand and laboratory.
Historically, ASTM has used the terms repeatability and reproducibility to describe the statistical basis for testing. In this context, repeatability means how closely the results of two tests run on the same oil in the same engine stand in the same laboratory match. If the results fall within a relatively narrow window, then the test is said to be repeatable.
Likewise, reproducibility is how closely the results of two tests run on the same oil in different laboratories match. Here, if the results are within a somewhat wider window, then the test is agreed to be reproducible.
These test programs are subjected to statistical analysis by industry statisticians to make sure the test is meaningful, and there are differences in the statistical approach theyll take for both repeatability and reproducibility.
Now that Ive bored you to tears with the statistical background, lets move on to the status of ILSAC GF-6. As I mentioned earlier, work on GF-6 and PC-11 started at about the same time. While PC-11 moved forward, GF-6 is struggling over two new engine tests that are being introduced. These are the Chain Wear Test (CWT) and the Low Speed Pre-Ignition test (LSPI). Both arise from modern, smaller-displacement engines that are designed for higher performance and improved fuel economy without loss of performance. Theres also the little matter that every existing engine sequence test used currently to evaluate oil performance, save one, needed to be redone with new engines and/or test procedures.
Lets look at the new tests first. The CWT measures the wear protection properties of oils in applications such as idle-stop engines, which include those that encounter frequent starts, starts after extended periods of downtime, or other similar driving modes. Based on a 2.0-liter Ecoboost engine from Ford, it also helps to evaluate various engine parts, not only timing chains but also valve train components.
The LSPI, also based on the 2.0-liter Ecoboost engine, measures the occurrence of engine oil-caused low-speed pre-ignition. The need for this test comes from the increasing numbers of smaller-displacement, boosted intake engines that may be susceptible to LSPI. In the olden days (when I started in the oil industry), pre-ignition was the result of fuel octane that was insufficient for the engines needs. Nowadays, the pre-ignition seems to occur at low speeds in 1.0- to 2.0-liter turbocharged or supercharged engines, and is the result of engine oil getting into the combustion chamber. The percussive outcome can be devastating and ultimately ruin the engine.
You might be thinking thats two engine tests for GF-6 and two in PC-11; should be about a match. But not so fast. In addition to these two completely new tests, updates are required to all of the other engine tests behind GF-6.
The Sequence IIIG, which measures oil oxidation resistance and deposit control. This test needs a new engine, since the old one is no longer manufactured, and both Chrysler and GM have offered a replacement. Chryslers version is proposed as the new Sequence IIIH for GF-6, and has completed matrix testing. However, there were test differences between labs, so further discussion is underway. Meanwhile, the General Motors Oxidation test (GMOD) has also completed matrix testing and could be included in GF-6, too. The data from that matrix program is being analyzed as I write this column, so we should learn more soon.
The Sequence IVB cam lobe wear test uses a Toyota engine, and has a test matrix running at this time. It replaces the IVA test, which used a decades-old Nissan engine. The matrix is scheduled to finish around May 1.
The Sequence VH is a sludge and deposit test designed to replace the Sequence VG, which uses a Ford engine no longer being made. Equipped with a newer Ford engine, this program has been delayed due to test fuel and hardware issues. A revised test, the Sequence VG-A, is being considered, which uses the VH engine block with VG heads. This is thought to be a way to get results that are of value. It was hoped that the test matrix could begin in March, with a mid-May completion.
The Sequence VIE and VIF fuel economy test matrices are currently running and should be done by the time you read this. The Sequence VIE, based on a 2012 engine from GM, is needed urgently because the existing fuel economy test, the Sequence VID, will run out of its 2009-era GM engines and parts before this years fourth quarter. However, the Sequence VIE does not have a provision for SAE XW-16 engine oils, so the Sequence VIF is also under development.
There is also the Sequence VIII test for bearing corrosion and shear stability, which will not change but is experiencing problems with a new batch of bearings. This requires a lot of effort to resolve and could delay the start of developmental testing for GF-6 oils.
The Chain Wear Test meanwhile is due to finish matrix testing, and test data will be analyzed and results reported in June. The LSPI test is also on schedule to complete matrix testing, with test data also analyzed and reported out around June 1.
That will give us a lot of engine test sequence data to digest, but there are a lot of other necessary steps before API can set a first license date for these new oils.
Over the next several months, as each sequence test is finalized and blessed, the American Chemistry Council will begin to register the tests for their Code of Practice program. ACC represents the additive suppliers in the approvals process, and the additive suppliers manage most of the engine test programs for the oil marketers. That registration process is expected to take until about Sept. 1. At that time, the additive suppliers can begin running the engine tests needed to technically demonstrate their additive systems for the new category. That is expected to take around nine months.
In the meantime, ILSAC and the Auto-Oil Advisory Panel will have to set test limits and approve the GF-6 specification, and API will need to ballot and bless the accompanying API Service Category (likely API SP). When these steps are finally in place, the mandatory waiting period begins. What that means is for a period of time agreed to by all involved, usually 12 months, additive suppliers and oil marketers will be finalizing and testing their candidate engine oil formulations. That one-year gestation period assures a level playing field for all competitors, and puts us in the April 2018 timeframe for API to first license GF-6 and SP products.
As Im sure you can see, this is not something the industry looks forward to with eagerness. Its long and detailed and complex – not to mention expensive. In fact, sometimes I think brain surgery would be a snap compared to the challenge of category change. Heres a tip of the hat to the men and women who take on this task.
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.