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About the Letters of Conformance (LoC)

For lubricant marketers
Under the European Engine Lubricant Quality Management System (EELQMS), lubricant marketers or manufacturers making claims against the ACEA Oil Sequences are required by ACEA to submit a Letter of Conformance to ATIEL.

Submission of a Letter of Conformance implies a commitment to develop and manufacture engine lubricants in accordance with the guidelines described in the EELQMS. Currently, over 200 lubricant companies worldwide have signed a Letter of Conformance.

In addition, ACEA members have confirmed in writing that to the extent that they market lubricants under their own brands, their suppliers have all signed the Letter of Conformance, whether or not the ACEA members make claims against ACEA sequences for the lubricants marketed under their label.

The Marketers' Letter of Conformance template can be downloaded below, along with a list of signatories.

Benefits of signing the EELQMS Marketers' Letter of Conformance

  • Only marketers siging the LoC can make product claims against the ACEA European Oil Sequences.
  • LoC signatories receive a licence to use the EELQMS logo on their product labels, documentation and other marketing materials.
  • Registration allow signatories to benefit from competing in a market that has established high quality standards and ensured enhanced compliance.
  • ATIEL's independent quality survey strengthens the quality image and the credibility of the performance claims of signatories' products.
  • The quality survey provides individual signatories with feedback on how their products perform.
  • Signatories have privileged access to training and educational materials.

For base stock manufacturers
Base stock manufacturers, including partner groups, wishing to declare that they manufacture base stocks in accordance with the ATIEL Code of Practice (Base Stock Quality Assurance guidelines described in Appendix B) may also sign a Letter of Conformance.

The Base Stock Manufacturers’ Letter of Conformance is shown in Appendix D of the Code of Practice and the template can be downloaded below.

New applicants, who have not previously signed a Letter of Conformance, should first register at and then submit their signed Letter of Conformance to:
Rue de la science 14B
1040 Brussels

ACEA 2016 Oil Sequences

Download the latest version of the ACEA Oil Sequences here.

This new update provides:
- A new revision of the ACEA sequences with the introduction of the new CEC L-107-19 test and limits (A/B and C categories) that replaces the Daimler M271 test and limits.
- An update to the ASTM D892 method (used to quantify the foaming tendency of engine oil) in respect of the applicability of test Option A (with or without the Option A sample pre-test procedure is permitted)