New ACEA Heavy Duty & Passenger Car Engine Oil Sequences Published

ACEA (EUROPEAN AUTOMOBILE MANUFACTURERS ASSOCIATION) – This body’s membership includes all the major European vehicle makers, both passenger car and commercial. They are responsible, with input from the additive & base oil manufacturers for agreeing and setting the engine lubricant standards for use in their vehicles. Developed by the European Association of OEMs, the ACEA sequences are a set of performance standards specifically tailored to the needs of the European market.

These tests are periodically reviewed and re-published around every two years and are known as “sequences”. Lubricant blenders and suppliers are required to sign a letter of conformance allowing them to quote the ACEA specifications on labels and product information.

ACEA specifications are all prefixed with a letter and then a number, for example you may see in a vehicle handbook a phrase like “A 5W-30 viscosity grade lubricant meeting the specification ACEA A3/B4”.

The prefix A indicates that the specification is designed for gasoline engines, and the B indicates a diesel engine. Many modern engine oils are capable of meeting multiple ACEA specifications simultaneously. The number relates to the category within that class and will have different physical and chemical limits.

So ACEA A3 is for a petrol engine that requires the characteristics of a class 3, the same is true for the B4. The ACEA classifications relate to:

• A/B Categories, Petrol & Light Duty Diesel Engines
• C Categories, Petrol & Light Duty Diesel Engines with Exhaust After-treatment Devices
• E Categories, Heavy-Duty Diesel Engines.

HEAVY DUTY ENGINE UPDATE 2022

A 2022 edition of the ACEA Oil Sequences for Heavy-Duty Engines has been published and the latest ACEA update incorporates several different changes to the categories. In the lower SAPS categories, we see ACEA E6 being replaced with the ACEA E8 and ACEA E9 being replaced with ACEA E11. And this will be for the new vehicles with aftertreatment devices. For legacy vehicles we see ACEA E4 and ACEA E7 higher SAPS categories being maintained to provide protection to vehicles already in the fleet.

One aspect of the changes is the inclusion and adoption of API-focused tests. This helps to bring greater global synergies across the API and ACEA categories, in aligning the global requirements for a minimum lubricant performance. The inclusion of the T-13 test brings new levels of oxidation control performance to ACEA E8 and ACEA E11.

Good oxidation performance is important throughout the life of the oil drain interval because it helps to prevent oil thickening and acid formation within the engine. And the Caterpillar oil aeration test in E8 and E11 incorporates improved aeration performance.

Control of oil aeration is absolutely critical to engine operation as it can lead to oil starvation and loss of power and accelerated engine wear.

Additional changes include an increased focus on biodiesel cleanliness and biodiesel compatibility through increased piston merit acquirements in the OM646 biodiesel cleanliness test. So biodiesel can change lubricant qualities, affecting its ability to continuously protect the engine, and we know that API categories do not have the requirement to check for lubricant biodiesel compatibility, while ACEA has a test that looks at the biodiesel compatibility of lubricants.

The latest engine hardware will also be included in the next ACEA update in the form of the OM471 test which brings both steel pistons in Euro VI technology. This new engine test will be included in ACEA E8 and E4 in place of the OM501LA,  with the option to Grandfather the OEM501LA in ACEA E4. The replacement of the OM501LA is also being explored to support ACEA E7 and ACEA 11 categories. Whilst not yet finalised, potential candidates include the Caterpillar 1N and or 1K single cylinder engine tests for a ACEA E7, and the Caterpillar C13 engine test for ACEA C13 test for ACEA E11.

As OEM’s focus more and more on increasing efficiency and reducing emissions whilst maintaining durability, future updates to the ACEA will likely include two new ACEA F categories, designed to offer enhanced fuel economy to the end user through a lower HTHS viscosity, in comparison to the conventional sequences that we see today.

PASSENGER CAR ENGINES UPDATE

The latest ACEA A7/B7 and C6 specifications, providing comprehensive coverage across the full 2021 ACEA European Oil Sequences for light-duty engines also concentrate on emissions and fuel economy.

The new ACEA Sequences came into effect on 1 May 2021 and were mandatory for all new claims from 1 May 2022. As such, the new Sequences, especially the new A7/B7 and C6 categories will play a critical role in shaping the European PCMO market for years to come.

A7/B7 is a new category building on A5/B5. Formulations meeting the demands introduced by A7/B7 need to combine low-speed pre-ignition (LSPI) performance, chain wear protection to address concerns with modern gasoline direct injected engines and provide cutting edge cleanliness to turbocharger compressors.

C6 is the corresponding reduced SAPS category, built on C5, adding the same engine performance features as A7/B7, but lubricants need to also pass a new fuel economy test to achieve the C6 specification. This new test arguably makes C6 the most important of the new categories because of the exciting fuel economy potential that can be achieved from formulating at SAE XW-20 grades.

Mick Kenyon – Witham’s Technical & Operations Director said

“The test limits for the new ACEA categories provide a challenging baseline, delivering critical performance features that are essential for the continued evolution of the European PCMO market. Our range of engine oils have been brought in line to ensure our customers receive on the very best in lubricant technology to help meet the rapid changes in engine and performance technology.”