ACEA oil sequences update

As you probably know, the European Automobile Manufacturers Association or ACEA, the trade group representing the top 15 European automotive OEMs, announced plans to publish new oil sequences in 2021. But you may still wonder:


  • What is driving these changes?
  • What do they mean for producers of lubricants for the European market?
  • And how is Oronite interpreting these revised standards?
First, a bit of context. The European Union has some of the world’s strictest regulations on fuel economy and vehicle emissions. Automotive OEMs have had to make significant changes in engine design to meet these standards, including reducing engine sizes, adding turbochargers to maintain power, and introducing Direct Injection (DI) to boost fuel efficiency.
These changes in engine design create a tougher environment for engine oils, with more intense power density and higher operating temperatures. Modern engine lubricants must be formulated to deliver optimal performance under these pressures. That is the chief driver for the new ACEA specifications – to ensure full protection for the newest generation of engines on the market.
Unlike previous updates, the ACEA has decided this year to stagger the releases of the new oil sequences for PCMO and HDMO. The PCMO sequences were released in April 2021, with the new HDMO sequences expected sometime later. ACEA 2016 sequences will expire two years after launch of the new oil sequences, and after that, oils based on the 2016 standards can no longer be marketed.
Now, let’s look at the PCMO and HDMO categories one by one.

PCMO sequences

Key changes to watch


  • ACEA A3/B3 categories will be removed; alternative recommendations will be ACEA A3/B4.
  • ACEA A7/B7 will be introduced as an upgrade for oils with a conventional chemical box. It includes the same performance testing as for ACEA C6 (except fuel economy).
  • ACEA C1 category will be removed.
  • ACEA C6 will be introduced to provide additional performance for today’s engine technology. It addresses fuel economy, LSPI protection, engine chain wear protection and turbocharger deposit control
ACEA plans to further specify the ASTM D4739 test method for Total Base Number (TBN) in the new oil categories. ACEA believes that this test method results in more meaningful TBN.
New testing requirements:
  • Turbocharger Compressor Deposits (TCCD)
  • LSPI (Sequence IX)
  • Chain Wear (Sequence X)
  • Fuel Economy (JASO FE)
Test phase out and replacement:
  • Low temperature sludge: Sequence VH replaces Sequence VG.
  • Piston deposits: VW TDi3 replaces the VW TDi2 test to match newest engine technology.
  • Engine sludge: Daimler M271 EVO test has replaced M271.
  • Valve train wear: sequence IVB replaces the already obsolete TU3 engine wear test.

the oronite view: how these changes affect current and future products

PCMO: The magnitude of the ACEA 2021 PCMO sequence changes will vary depending on the category. However, we see some general implications for current and future lubricant development:


  • For current products that meet the ACEA 2016 PCMO release specifications, the addition of valve train wear performance, through Sequence IVA or IVB, can address the ACEA 2021 requirements. Sequence VG, M271, and TDi2 tests can be used instead to evaluate current products for ACEA 2021 performance. However, since these engine tests are being replaced, new oil developments will require the completion of the latest engine tests (Sequence VH, M271 EVO, and TDi3), which is already the case for the new oil categories A7/B7 and C6.
  • For the newest oil categories A7/B7 and C6, performance screening will require a variety of tests focusing on different performance criteria:
    • Sequence IVB for valve train wear performance (no grandfathering of Sequence IVA results will be accepted)
    • TDi3 for piston cleanliness (grandfathering of TDi2 will be accepted)
    • Turbocharger Compressor Deposit Test (TCCD) for turbocharger cleanliness
    • Sequence IX for LSPI performance
    • Sequence X for chain wear
    • JASO FE Fuel Economy only for the C6 category
HDMO: As with the PCMO release, the extent of changes in ACEA 2021 HDMO sequences depends on the category:
  • For current products meeting E4 and E7 per ACEA 2016 release, the upgrade to ACEA 2021 will almost be automatic. No new test is included in the new release, although there are some new limits in foaming tendency (ASTM D892 and ASTM D6082) and elastomer compatibility (CEC L-112).
  • For the new oil categories, the performance upgrade from E8 and E11 to E6 and E9 becomes more significant, New tests looking for improved piston cleanliness (OM471), oxidation resistance (Volvo T-13) and aeration performance (COAT) are required.

keeping up with evolving standards

The step-up performance demands of the new ACEA 2021 release underscores the need to bring products to market that meet the standards of The European Engine Lubricant Quality Management System (EELQMS). Avoid using crankcase lubricants with unsubstantiated claims that do not follow Industry Codes of Practice and lack adequate supporting data. Although ACEA claims are self-certified, any ACEA claim requires the oil marketer to sign a Letter of Conformance with EELQMS quality standards.


All these changes highlight the importance for all industry stakeholders to keep offering products that meet the requirements of current vehicle fleets, while developing new lubricants that will keep up with the evolution of engine hardware – the main reason for the introduction of new ACEA oil categories.