Do Customers Still Have to Use the OEM Recommended Oil?OEM recommendations have forced auto maintenance and fast lube shops to carry multiple oil brands, which can be cost prohibitive. Many of those affected have chosen to be brand specific in order to have availability of the required products. It’s either that or have a very large inventory of seldom used product.
The question asked over and over is, “After the warranty, do I still have to use OEM recommendation?” Customers are feeling frustrated and confused, especially with the prices of the synthetic oils that are being recommended. So what happens if you use conventional oils in a vehicle that is beyond warranty but was originally recommended synthetic products?
Before you can answer the question “Can you…?” you need to understand how an OEM decides what the oil recommendation and drain interval should be. It’s a question that deserves an answer, so let’s see what we can learn about the process.
There are several criteria that go into the decision about what to use and how long to use it. Some of the reasons are very straightforward. Is it gasoline or diesel fueled? Has there been any major change in engine design that would call for different oil? Others are more complex. Have emissions or fuel economy regulations changed? Have there been field issues with the current recommendation?
To understand the forces driving new and specialized oil specifications, you need to understand the process for creating a new API category, since most of the oil sold meets these standards. The current system calls for the American Petroleum Institute (API) and the International Lubricants Specifications Advisory Committee (ILSAC) with input and support from ASTM and the American Chemistry Council (ACC) to propose, develop and implement new oil categories for both passenger car and heavy-duty engine oils.
Since you can’t tell the players without a scorecard, let’s describe each organization briefly.
- API – This is a marketing organization representing the oil industry and their marketers. They are looking out for the oil manufacturers and marketers interests. (Fewer oils and tests that are reasonable in cost and severity.)
- ILSAC – A consortium of North American and Japanese automakers and HD engine builders. Their concerns are to try to minimize any oil related failures and to prepare for future designs and other issues. (Lots of oils for specific engine designs and tests that truly reflect their needs.)
- ASTM – A technical organization that bears the responsibility of developing and maintaining engine test procedures and ensuring they remain repeatable and reproducible.
- ACC – They represent the additive suppliers who are charged with developing the additive systems to meet the new requirements. (They tend to fall more in line with API than ILSAC.)
The process involves a number of steps including a needs statement from ILSAC followed by agreement from API and ACC to move forward. Then, there is a meticulous process to develop and prove-out new limits for existing tests or new tests, followed by proving the tests will work and then time for ACC to develop new products to meet the new test requirements. After that, there is a one-year waiting period to allow all oil marketers to develop and register their oils for API approval.
One of the criteria for any new oil category is that it will meet the needs of previous oil categories. This is called “backwards compatibility.” Simply stated, this means that the most recent oil category will be satisfactory for older engines.
By the time this process has been completed and a new category introduced, years may have passed. In the case of the next category, API GF-6, the development process started in 2012 and is not complete as of today. Best estimates by API and ILSAC are that it will be sometime in mid-2020 before we see GF-6. The reasons for this delay are many and varied, but when you consider that there are seven tests that have gone through major updates and three completely new ones, it’s easy to see how it could take a long time to finish the process.
Since this process is time consuming, it means a lot of compromises are made. Most often, the ILSAC members are into engine designs that may not be covered by API categories for some time. If there is a serious concern or field issues, they will react by creating their own test to protect themselves. Their test procedures are developed very quickly and don’t go through as rigorous of a development process as the EOLCS dictates. However, it does serve their needs. Ford’s recent development of a diesel wear test for their 6.7L engines is an example of this. They were also the lead company in pushing through API SN Plus, although there was agreement within ILSAC on the need for the new category.
For some of the international OEMs, there is an additional desire, and that is to unify their oil specs. The GM dexos system is a good example. The dexos oil specifications include not only the API category requirements, but also include European tests and GM developed tests. The advantage is that a dexos approved oil can be used anywhere in the world for GM vehicles.
The OEMs have another reason for their own brands. They have traditionally felt that the API categories should have a built-in process to allow upgrades without all of the formality of the EOLCS process. They are great advocates of the “continuous improvement” concept that states improvement should be ongoing rather than stepwise — which is what the EOLCS method does.
That explains the number of oil specifications in addition to the API categories. The question then is if or when can you stop using engine oils recommended by the OEMs.
It should be apparent that the OEMs would like you to continue to use their oil. That’s a purely marketing view. They’re selling oil now and want to continue to sell it. The group within any OEM selling their branded oil is not the same group that is selling vehicles. Each has their own profit targets within the company and want to keep the business healthy.
The reality is, when a vehicle is out of warranty (say 50,000-75,000 miles), oil quality has probably changed creating a more robust product. Whether it is API or an OEM, the oil will be more oxidatively stable and able to extend drain intervals even more than currently. The additive package will probably have more friction reducing capabilities, better wear protection and even be able to perform satisfactorily in new engine designs which may incorporate direct injection, turbocharged, gasoline fueled powerplants.
Viscosity grades are more or less consistent across API categories. The SAE J300 viscosity classification is based on four viscosity tests. One is a high-shear-rate test at 150 C, which simulates oil viscosity in operating bearings. The second is a low-shear-rate (kinematic) viscosity at 100 C. This simulates pouring the oil out of the bottle, but also simulates oil flow in the engine out of the oiling rings into the ring/liner interface. The third test is a low-temperature, high-shear-rate test that simulates the viscosity in cold cranking, such as starting the engine at very low temperatures. The test temperature varies with the kinematic viscosity and ranges from -35 C for SAE 0-W to -10 C for SAE 25-W. The fourth test is a low-shear-rate, low-temperature test, which simulates the viscosity at the oil pump pickup screen and the oil’s ability to pump at very low temperatures. This too, has varying temperatures from -40 C for SAE 0-W and -15 C for SAE 25-W. You may notice that the pumping temperature is 5 degrees lower than the cranking temperature. This is to make sure that if the oil can allow the starter to crank fast enough to start the engine, it will be able to pump though the engine and protect all surfaces within a reasonable time.
So where does that put us on the question of when can I stop using the recommended OEM synthetic product and go to a conventional, less expensive oil which is widely available. Once it’s out of warranty, the owner has the choice. There is a small percentage (market research says about 5 percent) who always want the very best product. That group will likely want to stay with the OEM oil. There is a much larger group who is brand loyal and will want to use the recommendation from their favorite. Finally, there is the cost conscience buyer who will opt for the lowest price. There’s little question that backwards compatibility will assuage the fears of the operator and the vehicle owner, providing they both understand what that means. Beyond that, it’s a part of the sale.