Sure enough, Bengt suggested writing about why API FA-4 oils, the fuel economy version of the latest heavy-duty engine oil specification, seem to be slow entering the market. He speculated that it may have something to do with poor support from heavy-duty engine builders.

That was all it took for me to start contacting original equipment manufacturers, as well as additive companies and oil marketers, for their input. First, lets look at the current situation. The American Petroleum Institute licenses all currently active categories, both passenger car and heavy-duty trucking engine oils.

API CK-4 and FA-4 went active on Dec. 1, 2016. Twenty months later, the number of licenses for both categories are telling. While there are 895 licenses for API CK-4 oils, only 94 FA-4 oils are licensed.

If we can assume that both categories use the same additive and base stock systems (reasonable), why is there such a disparity in the number of approvals?

It goes back to that pesky concept of backwards compatibility. I know that Ive been working this over pretty hard and often, but it does have a major impact on what oils can be used. Earlier API categories were all based on a minimum 3.5 centipoise high-temperature, high-shear rate viscosity. Back in the day, that was the viscosity needed by the big Cats, Macks, etc.

Times have changed. Newer engines are going for lower viscosities (API FA-4 specifies 2.9 to 3.2 cP) in order to capture fuel economy savings. In an article from Fleet Equipment Magazine, Colin Repco of Lubrizol offered a graphic analysis of how a 2 percent fuel economy savings can greatly impact a trucking fleets bottom line. The example in the table above shows the total fuel and cost savings for an imaginary fleet of 2,000 trucks driven an average of 100,000 miles in one year.

In a separate Fleet Equipment Magazine article on API FA-4, Repco said, Lubrizol views the rollout of API FA-4 as quite successful from a technical and performance perspective. He also noted that there are some challenges ahead, including fleet awareness and understanding of FA-4; fuel costs, which have dropped, making the introduction of FA-4 less urgent; and the varying levels of OEM acceptance, as well as backwards compatibly concerns.

You can quibble with the details, such as fuel cost, but the impact is clear. Repcos example results in a $1.5 million savings for this hypothetical fleet. Even an owner/operator can save over $750 per year in fuel costs on a single truck.

Lets look at the potential impact of a 2 percent fuel savings across the entire Class 7 and Class 8 fleet. There are about 5 million of these vehicles in service. Since the beginning of 2017, there have been about 600,000 vehicles sold. Using Repcos analysis, the industry as a whole could conceivably save $3.75 billion per year! I say conceivably because the average age of the fleet overall is about 11 years.

But, you say, its only since 2017 that engines could even conceivably be compatible with API FA-4 oils, and those trucks number 600,000. Actually, only Daimler North America factory fills with FA-4 and recommends its use back through 2010. Were now down to about 240,000 vehicles. You can do the calculations to see how our 2 percent fuel economy improvement works out.

I can play with numbers, but the engine builders have a lot more insight than I do. So I asked Greg Braziunas, manager of transmission, clutch, fluids and test planning for Daimler NA, for the companys view on the subject. He said, The simple fact is that large North American fleets cannot manage more than one fluid in their fleet, and unfortunately, they have some mix of older equipment, which is not FA-4 approved.

Braziunas noted that Daimler is the only OEM allowing backwards compatibility with API FA-4. He pointed out that they also are concerned with secondary equipment, such as refrigeration units. The small engines used in these are not FA-4 approved. Fleets still want only one oil to cover every application, including their small equipment.

Braziunas also said there are supply and price problems with API FA-4. Its a catch-22 scenario: Price is high and supply network is poor, so fleets cant switch; but because no fleets are switching, the price remains high and the supply network remains poor.

My next contact was Greg Shank, executive staff engineer coordinator for fluids technology with Volvo Group Trucks Technology. Greg is also heavily involved with the Engine Manufacturers Association, which drives the development of needed upgrades for heavy-duty engine oils. One of Shanks points is that a lot of oil specification changes are driven by hardware changes. For instance, API CI-4 (2010) was the result of some major hardware improvements, as was API CK-4. API FA-4 was a desired change to improve fuel economy.

Shank also observed that many fleets are mixed vehicles; they have not only Volvos but also Daimler NA, Navistar and other engines. This causes some problems, but as long as everyone specifies API CK-4, the supply of lubricant is simple. However, when more than one oil is specified, logistics become a real problem, just as Daimlers Braziunas said. Shank also noted that nearly all the major OEMs specify SAE 10W-30 API CK-4 oil as factory fill. (Daimler uses SAE 10W-30 API FA-4.) Most fleets are now using SAE 10W-30 CK-4 oils, which offer some fuel economy benefits, and Shank says that customers are beginning to select API FA-4 in order to capture the fuel economy benefits that I outlined earlier.

Ford Motor Co. is recommending API FA-4 for its 3.0 liter and 1.5L diesel engines. These are smaller engines, with less torque and power than the 6.7L, so they are capable of using the lower HTHS viscosity API FA-4 oils. For the larger engines (3.2L, 6.7L), as well as older engines, Ford continues to advise against the use of CK-4 and FA-4 oils, instead recommending its own WSS-M2C171-F1 specification.

When you look at it, the OEMs seem to be in alignment on the situation regarding API FA-4. But how do the oil marketers feel about the subject? I went to Chevron, since they are a major marketer of heavy-duty engine oil. If you expect a completely different viewpoint, Im afraid youll be disappointed. Shawn Whitacre echoed Braziunas and Shanks views on the subject. He noted the logistics issues with multiple oil requirements as well as mixed fleets. He also pointed out that customers are more frequently asking for SAE 10W-30 oils. Certainly, the step to FA-4 should be relatively small.

Josh Frederick from Valvoline noted that in the U.S., only one OEM (Daimler) has actually recommended the use of API FA-4 engine oils in their engines. While other OEMs will allow it in their newer engines, the messages about backwards compatibility are somewhat confusing and inconsistent. Frederick pointed out that the move to FA-4 oils will happen, and he thinks that SAE 10W-30 FA-4 oils will be used more prevalently in the future. It could be a while, because older engines will have to age out of fleets and more OEMs will have to recommend the use of FA-4 oils.

The view expressed by Kevin Ferrick, senior manager of APIs Engine Oil Licensing and Certification System, is that fleets, repair shops and technicians need to learn how to manage CJ-4, CK-4 and FA-4 oils. Given the challenges to convert to an oil category that isnt backwards compatible with current products creates many opportunities to get it wrong. Caution is the key word here.

The key to API FA-4 growth in the North American marketplace comes down to a few bullet points:

OEMs will need to see a lot more data on older engines before they will be comfortable with greater backwards compatibility for FA-4, and that may never happen.

As new engines come into the market, they will all be FA-4 compatible.

Fleets will ultimately change over to FA-4, but only when their older engines are gone, availability is good and prices are more in line with current SAE 10W-30 API CK-4 products.

The oil marketers are ready to supply these oils but need sufficient volume to justify a more competitive price and availability structure.

Everybody wants FA-4. Its only a matter of time.

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.