March 5, 2019
Volume 3 Issue 4
Europe Tackles Read-Across, Interchange
LONDON – Europe’s lubricant industry has fallen far behind in the development of base oil interchange and viscosity grade read-across guidelines, having written almost none for the past two decades despite dramatic changes in base stocks and automotive engine oils.
That was the admission of an industry insider at the ICIS World Base Oils & Lubricants Conference here Feb. 22. He added, though, that industry groups are now working to remedy the situation and recently took the first steps toward providing these tools that can help lubricant suppliers cope with the growing complexity of engine oil specifications.
“We are aligned and committed to progress base oil interchange and viscosity grade read across guidelines for the collective industry as a whole,” said Ari van de Ven, an executive committee member of the technical association of Europe’s lubricant industry, known as ATIEL, referring to a cooperative effort between that group and the Additive Technical Committee. “We go slow [to date], but I think we have made quite some progress over the last years, and hopefully we can accelerate.”
Base oil interchange and viscosity grade read-across guidelines are supplements to lubricant specifications, meant to save testing costs and provide flexibility to lube blenders who want to make adjustments to product formulas. In order to be promoted as meeting industry specifications, finished lubricants must pass a series of tests which generally are growing in number and expense. Testing for the latest light- or heavy-duty engine oil specifications can cost $1 million or more.
Having gained certification that a formula meets a specification, a lube blender may want to tweak the base oil content of a product from time to time if, for example, they experience disruptions in deliveries of base stocks that they normally use or if they have an opportunity to make a spot purchase of a similar base stock at an attractive price. (ATIEL emphasizes that, as a technical association, it does not conduct its work in pursuit of commercial considerations.) Base oil interchange guidelines establish rules about the extent to which base oils may be replaced without having to retake tests and obtain approvals for a new formulation.
Read-across guidelines allow marketers to apply approvals to lubricants of different viscosity grades if it has been determined that the product will reliably meet the requirements of the second vis grade. For example, if an SAE 5W-30 passenger car motor oil that passed the CEC’s OM646LA wear test, read-across guidelines may permit the assumption that 10W-30 and 10W-40 versions of that product also pass the test so long as the viscosity modifier content does not increase by more than a certain amount. But the same assumption may not be permitted for a 0W-30 version of the product.
Interchange and read-across guidelines are specific to certain tests and base oil API groups. European and North American specifications have extensive guidelines for Group I base stocks, which were developed in the 1990s. But while North American specs also have significant amounts of guidelines for Group II base stocks and lesser amounts for Group III, van de Ven, who works for Q8 Oils, explained that European specs have almost none.
The lack of European guidelines is somewhat eased by the inclusion of ASTM engine tests, developed in North America, in oil sequences of ACEA, the European Automobile Manufacturers’ Association. Those ASTM tests do have interchange guidelines. Still, guidelines for Europe’s CEC tests have been sorely missed, van de Ven said, as the number of oil categories has increased (ACEA engine oil sequence categories increased from eight to 14 since 1996), as the number and expense of engine tests rose, as the number of base stocks on the market expanded and as the engine oil market shifted to lower viscosity grades.
“If you look in the EU at the interchange guidelines that we apply, they are still based on what we did and what we defined in the 1990s – they are Group I based,” he said. “We have nothing for Group II or Group III.” The lack of such guidelines, he added, “makes it quite complex and also quite expensive” to blend engine oils in today’s market.
That’s because European organizations developed almost no new guidelines during the past two decades, when engine oil formulations shifted from Group I to Group II and III base stocks.
The reason that Europe stopped developing guidelines while North America continued, he said, stems from differences between the organization of specification development between the two regions. In North America, interchange and read-across guidelines are integral parts of specification development. In the European Union, guidelines are developed separately. In North America, read-across guidelines are available at the introduction of a specification, while in Europe they are not. In North America, original equipment manufacturers as well as oil and additive companies contribute funding for development of guidelines, while in Europe only oil and additive companies contribute such funding.
Six years ago, Europeans set out to address the problem. In 2012, ATIEL and ATC formed a work group tasked with developing the region’s own guidelines. By 2015 they had written rules for development of read-across guidelines, including a system for collecting oil performance data from members and for evaluating that data.
The next year they established a mechanism to fund development of read-across guidelines for the CEC EP6 Test for oil deposit control. The guidelines for that test were completed late last year and will be included with the adoption of ACEA 2018 oil sequences, expected this year.
Van de Ven called these rules a significant development but said they also illustrated the challenge of filling in the gaps of European guidelines. There is broad consensus within the industry that oil formulations can often be tweaked without compromising performance. However, ACEA insists that modification without retesting only be permitted where testing has proved that that particular adjustment – the substitution of one Group III oil for another, or the replacement of a Group II with a Group III – does not hurt performance. The problem is that testing is expensive.
A reasonably helpful read-across guideline might cover three viscosity grades from three base oil slates covering two base oil groups. This would require 22 tests at a cost of €67,300 each for a total bill of nearly €1.5 million, van de Ven said. If the program were expanded to three groups, the expense would balloon to more than €2 million.
And tests needed to develop interchange guidelines are approximately twice as expensive, he added.
ATIEL wants to continue developing guidelines but recognizes such an effort will face challenges such as corralling the various organizations that would need to be involved and finding the necessary funding.
“That’s not an easy task,” he said, “but I think at the moment – with the complexity increase that we in the industry observe – now is the time to start working together and to try to reduce the complexity.”
ATIEL has therefore created a task group charged with finding the most effective development method, determining the cost and finding a mechanism to cover those costs.
The organization has also concluded that the European industries should make guideline development and funding part of specification development, as their North American counterparts do.
“It is ATIEL’s position that both should happen simultaneously with test development. If we do those three together, then we believe the total cost will be less than if we do them sequentially,” he said.