This makes the fourth time in a decade that ACEA has updated its Sequences – in 1996, 1999 and as recently as 2002 – and shows how fast engine oil developments must sprint to keep pace with engine technologies and environmental mandates.

The new system looks a bit different than the one that preceded it – and greatly different from the American Petroleum Institutes Service Category system used in North America and many other places around the world. In the ACEA system, for starters, a letter defines the oils class (light-duty gasoline, heavy-duty diesel, etc.), followed by a numeral indicating the oils category.

In this latest update, ACEA abandoned its stand-alone class B for light-duty diesel engine oils, and combined it with the light-duty gasoline engine oil class (A). So for the first time in a decade, a single class – A/B – is available to lubricate both light-duty diesel and gasoline engines. By doing so ACEA was able to substantially simplify its classification system, reducing the number of light-duty engine oil categories from 11 in 2002 to just four now (see table, page 10).

Also for the first time, a class for catalyst compatibility oils (C) was established, for use in gasoline and diesel engines with aftertreatment devices such as diesel particulate filters and three-way catalysts. There are three categories in this group, including one that addresses low SAPS oils, which contain reduced levels of sulfated ash, phosphorus and sulfur.

ACEAs third class (E), for heavy-duty diesel oils, still has four categories; two new categories were added while two from the previous system were eliminated.

Claims to meet the 2004 Sequences were first allowed Nov. 1. Through Nov. 1, 2005, oils can meet the requirements of either the 2002 or 2004 specification. From then, new oils can be qualified only by meeting the 2004 specifications. And a year later, on Nov. 1, 2006, the 2002 specifications will be officially withdrawn. So ACEA has built up-front into its Sequences an explicit time period that an oil quality level can be in the market. This pattern has held for a decade.

The defining difference between the two systems, European and North American, is this: ACEA Sequences have quality tiers and resource conservation built into them and API Service Categories do not. ACEA Sequences are multilevel and structured to allow, in fact compel, a market that includes the option of extending drain intervals, while API Service Categories are single-level, with no mechanism to provide for extended drain intervals.

Who Owns It?

In Europe, engine oil quality upgrades are the responsibility of original equipment manufacturers, represented by ACEA. Headquartered in Brussels, ACEA has 13 member companies, all major European car, truck, and bus manufacturers; it represents over 90 percent of European Union vehicle production and more than 40 percent of production worldwide. Its member companies provide roughly 1.1 million jobs in Europe and another 1.6 million in other parts of the world.

In the United States, by stark contrast, its the producers, manufacturers and marketers of engine oils, as represented by the American Petroleum Institute, who own the engine oil specification system. So in Europe, the users and specifiers of engine oil own the system and its rules; in the United States, the oil suppliers do.

Ownership is very important to European OEMs. As a representative of a major vehicle manufacturer succinctly put it: Our vehicles, our specifications.

Ownership, however, does not mean exclusion, ACEA members insist. As ACEA develops new oil sequences it does not exclude other stakeholders, especially oil and additive companies, throughout the process. There is value to OEMs owning the oil Sequences because we then have the final word, dont have to commit to a formal consensus routine which could slow us down, and we can keep the process flexible. This is very important, Volvos Bengt Otterholm, leader of the ACEA heavy-duty working group and a longtime participant in developing both European and worldwide heavy-duty specifications, told LubesnGreases.

At the same time, he continued, we actively inform and seek comment from oil and chemical additive companies during our developmental process. We meet on a need-to basis, there is a continuous exchange of views and the process is cordial. While we have faced contentious issues, at the end we have been able to sort them out and are quite satisfied with both the process for developing the 2004 Sequences and the technical outcome.

His comment was seconded and fully supported by Carl Stow of Ford Motor, spokesman for the light-duty working group, and its leader, Sven Kossmehl of Volkswagen.

Tracking the Changes

Bengt Otterholm has led the ACEA heavy-duty working group since 2000. This groups primary function is developing new diesel engine oil Sequences, but it also reviews other engine oil related issues and keeps an open dialogue with its sister organizations, the North American based Engine Maufacturers Association and the Japanese Automobile Manufacturers Association.

Recently, Otterholm talked with LubesnGreases about the rationale and drivers facing ACEA as they undertook development of the 2004 heavy-duty oil Sequences. Like the United States, Europe has imposed stringent emission requirements and these are constantly being tightened.

While there may appear to be substantial differences between the 2002 and 2004 heavy-duty categories – with the addition of two new ones (E6 and E7) and the deletion of two old ones (E3 and E5) – this is not the case, Otterholm went on, pointing to the consumer language used to describe the heavy-duty categories.

The 2002 E5 category was eliminated but the new E7 is very little different from E5, he said. The only engine test difference is that the Mack T-9 engine test in 2002 has been replaced by the Mack T-10, which measures ring and liner wear, in 2004 – which is not a brand new test anyway.

Also, we have moved from 30 cycles to 90 in the newly added ASTM test method D-6278 for determining shear stability, which we did to comply with the requirements of APIs new supplement, CI-4 Plus. The changes incorporated into E7 made E5 superfluous and not necessary to retain.

E3 is also, in principle, now superfluous because that type of application is also covered by E7 type oils, he added. So the deleted heavy-duty categories have simply been replaced by new ones, leaving the number of categories the same and the technical coverage identical. So there is very little effective difference on the heavy-duty side.

Moreover, the cost to qualify a 2004 heavy-duty oil is also similar to before. The primary cost for qualifying a new oil is the number of engine sequence tests it must undergo, Otterholm points out.

E6 is a brand new class, he went on, and the only one that directly addresses the recently upgraded environmental specification, called Euro IV. The Euro IV emissions standard takes effect October 2005, and [E6] is designed to protect engines meeting tightened emission requirements, especially engines equipped with diesel particulate traps and operating with low SAPS. Lower SAPS, particularly phosphorus, can reduce the wear protection provided by an oil. However, E7 oils are also compatible with and designed for Euro IV engines, in particular the ones based on the less lubricant-sensitive selective catalytic reduction (SCR) technology, he pointed out.

Extended Service

As for the issue of drain intervals, its addressed by name in each of the four heavy-duty diesel oil categories. The consumer language for E2 oil says it is intended for medium-to heavy-duty cycles and mostly normal oil drain intervals; E4, E6 and E7 are for engines running under very severe conditions, e.g. significantly extended oil drain intervals according to the manufacturers recommendations.

Drain intervals, quality level tiers and prices are linked, of course. Otterholm notes, E7 oils are the most cost effective lubricant type because this specification can be met by a mineral base oil, Group I, whereas E4 and particularly E6 almost always require either a Group III or IV base oil. The considerably higher price of these base oils, compared to Group I, means that finished E4 and E6 oils are always much higher priced than E7 oils.

While E7 oils are the most widespread marketplace heavy-duty oils, the penalty for these lower-priced E7 oils could be a reduced drain interval.

Drain intervals are of great importance and a strong competitive issue for heavy-duty vehicle manufacturers. At Volvo Truck, Otterholm notes, Our drain interval recommendation is 62,500 miles (100,000 kilometers) for light, over-the-road [long-haul] service and the highest oil quality. From there, the intervals drop with increased service severity and decreased oil quality. Some other OEMs have even longer drain interval recommendations. But our recommendation is very, very dependent on the application, such as over-the-road, short stop-and-go driving, etc.

Although each OEM establishes its own drain intervals, competitive pressures compel all manufacturers recommendations to be in the same ballpark.

Other issues worth noting with the new heavy-duty oil Sequences:

OEM Buy-in. With the exception of one company, all European heavy-duty diesel engine manufacturers have individual company specifications for their vehicles. Company specifications are based on ACEA specifications but each one is different, tailored to a companys requirements. Only Turin, Italy-headquartered Industrial Vehicles Corp. SpA (Iveco) is satisfied with solely recommending ACEA specifications for its vehicles.

Backward Compatibility. Backward compatibility of 2004 heavy-duty oils with earlier Sequences is not an issue. All OEMs accept that the 2004 E7 category is fully backward compatible with the 2002 E5 category it replaced. However, some OEMs may reduce the drain interval to ensure backward compatibility, especially with E6 because of the low phosphorous levels, remarked Otterholm. For Volvo, we are entirely satisfied that 2004 oils are backward compatible with 2002 oils, while maintaining our usual drain intervals.

Global Reach. During the development of the 2004 Sequences we had considerable contact with the Engine Manufacturers Association in the United States but not with API, Otterholm reported. We seek comment from EMA because we use U.S. tests in our Sequences such as the Mack T-10 and the Cummins M11 EGR. In our 2002 E5 category and now E7 there is definitely a convergence with API CH-4 and CI-4.

We are closely following the development of [APIs proposed new diesel category] PC-10, and as of now believe it is moving along quite well. Jim McGeehan of ChevronTexaco, the chairman of the ASTM panel, is very experienced and the right person for the job of moving PC-10 to a successful completion.