The new API heavy-duty engine oil categories are in place and active. Thats good news for many in the industry including oil marketers, customers and original equipment manufacturers. But, as Gilda Radner used to say on Saturday Night Live, Its always something! It seems that at least one OEM has concerns about the new specs. Ford has issued a warning and a new specification to address the concerns they have with both API CK-4 and FA-4.
Its not as though this is something new. Ford first raised their concerns about wear in their 6.7L diesel engines in December 2014.
Lets go back to the presentations they made two and a half months ago at the Oct. 26 Diesel Engine Oil Advisory Panel meeting. Ford reminded the industry that tests had identified some CK-4 prototype formulations that may not be as robust on wear protection as existing CJ-4 formulations. Ford has seen accelerated valve train wear in their 6.7L engines with some CK-4 and FA-4 formulations with less than 1,000 parts per million phosphorus that they havent seen with CJ-4 oils. Based on these results, Ford has wear concerns about CK-4 and FA-4 in both new and older Ford engines.
Why would oil marketers drop down to 800 ppm phosphorus from the 1,000 ppm in CJ-4 oils? The answer lies in the Engine Oil Licensing and Certification System (EOLCS), known to many as API 1509.
Oil marketers have offered what are commonly called universal oils for upwards of 40 years. The concept is that one oil could cover the needs of both diesel- and gasoline-fueled engines, allowing end users to stock only one oil for their mixed fleets of vehicles. Its a great idea when you consider that stocking more than one oil in a maintenance facility could easily result in using the wrong oil in an engine. Wrong oil equals an early rebuild or even premature engine death.
API 1509 established a set of guidelines which allowed oil marketers the chance to supply these oils without excessive amounts of testing. Basically, a qualified diesel engine oil could be labeled with an API gasoline category without a lot of extra engine testing. It helped that all engine oils, both gasoline and diesel, required a passing ASTM Sequence III test. The Sequence III measures oil oxidation resistance, deposits and wear protection. Its been a mainstay of the oil testing business for years.
Changes happen, and API made a big one by dropping the Sequence III for oxidation and replacing it in CK-4 and FA-4 with the Volvo T-13, which is run only in diesel engines. There are no more gasoline fueled engine tests associated with CK-4/FA-4. But there are three wear tests that almost all in the industry thought would cover any wear concerns: the Cummins ISM, Cummins ISB and the Roller Follower Wear Test.
As I mentioned, API 1509 had made some allowances for relaxing category requirements to make it easier to get a universal oil into the marketplace. With the introduction of CK-4 and FA-4, there is no relaxation. A CK-4 or FA-4 oil must meet all of the requirements of the S category for gasoline engine oils that it is claiming as a universal oil. Well, all of the active S categories have some restriction on phosphorus content. In fact API SN, which is the most current gasoline category, has an 800 ppm limit on phosphorus.
Fords contention is that some oils meeting the CK-4 or FA-4 specifications may lack the level of phosphorus required to adequately protect their 6.7L diesel engine. The 6.7L is important to Ford since it is one of the two engines sold in their perennial number one in sales: pickup trucks. About 200,000 6.7L engines are used annually in Ford pickups and are touted as the most powerful engines in their line. For 2017, these engines put out 440 horsepower with 860 foot-pounds of torque.
Fords response to this situation is to not recommend CK-4 or FA-4 to service any Ford diesel engines at this time. Ford will continue to recommend CJ-4 oils with more than 1,000 ppm phosphorus. In addition, these should be oils that were licensed to CJ-4 prior to 2016-without showing CK-4 in the API donut logo.
Historically Ford has always recommended API diesel categories for its engines. Now the company is requesting that API change both CK-4 and FA-4 to include a minimum phosphorus level of 1,000 ppm. The OEM also wants oils with less than 1,000 ppm to be labeled as low phosphorus as a part of licensing.
In addition, Ford has introduced a new specification that will contain additional wear requirements, identified as WSS-M2C171-F1. They will have an official approval program for this specification and publish an approved products list. The new specification includes all CK-4 requirements and limits, plus a Ford 6.7L valve train wear test. Test development is in progress with estimated completion in the first quarter of 2017. At that point, the new test will be turned over to ASTM to be published as an industry standard test procedure.
Until the 6.7L engine test is completed, Ford will require 1,000 to 1,200 ppm phosphorus, a CJ-4 formulation licensed prior to January 2016, and an antioxidant boost to meet CK-4 limits for the Volvo T-13 oxidation test. Other testing conducted on the 6.7L engine may be used if approved by Ford Motor Co. prior to testing.
Youre probably asking yourself if this is a new OEM specification that will be similar in nature to General Motors Dexos. I dont think so. It is a specialized requirement which could be eliminated if the oil marketers can demonstrate satisfactory protection using CK-4 oils in the 6.7L test. In fact, if that can be achieved, meeting Fords specification would add to an oils pedigree.
I should also mention that API says they always recommend that consumers follow vehicle and engine manufacturer recommendations, so they would direct Ford owners to follow Fords guidance. This means recommending that Ford owners use CJ-4 oils, which will be licensable and available for the foreseeable future.
As for FA-4, Ford doesnt want to use it either. They are concerned that its reduced high temperature, high shear rate viscosity would be detrimental to wear as well. They have categorically stated that they dont want FA-4 oils used in their vehicles. Thats interesting, since it takes away the possibility of improved fuel economy (and reduced emissions) available from low viscosity oils. Obviously, part of the approach by oil marketers and especially additive suppliers will be to develop formulations which pass the Ford 6.7L engine test. Once again, meeting another specification provides additional marketing opportunities.
The question you must be asking yourself at this point is, why did we get so far down the road-actually at the end-before this problem came to light? I think there are several factors at work here. First, Ford was having a bit of difficulty defining the problem. They were certainly hoping that CK-4 and FA-4 category oils would meet their needs and prevent wear problems from occurring. There are those in the industry who think that the Cummins ISB test could have predicted the problem, but no one is having ISB problems.
What Ford saw was that CJ-4 oils, especially those approved before 2016, gave them the performance they needed. Could there be formulation problems in the industry?
A second possibility is the engines themselves. What might have changed which could cause these wear issues? I sure hope Ford has studied this aspect of the problem. Perhaps there are metallurgical causes that have gone undetected. There are lots of design issues which could play a part in this situation. Oil pump pressure and sizing come to mind.
Of course its easy for me, a chemist who is by most accounts nothing more than a driveway mechanic, to analyze the situation and come up with a dozen reasonable sounding ideas for whats going on. However, there are quite a few real engineers at Ford who are working this problem hard. Im going to back off here and let the big boys find the answers so we can press on to the next oil category change, which is coming sooner than many think. As I said at the beginning, its always something.
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.