The Technical Association of the European Lubricants Industry (ATIEL) has issued an updated version of its engine oil Code of Practice that, for the first time, formally addresses the use of re-refined base stocks in automotive engine oils. Issue 26 of the Code took effect Dec. 19, 2025, replacing Issue 25 and applying to products marketed under the European engine oil quality system, according to the association.
The revision reflects a broader shift in the European lubricants sector as manufacturers respond to evolving regulatory requirements, sustainability objectives, and customer expectations. Rerefined base stocks, often referred to as RRBO, have gained attention as part of industry efforts to improve resource efficiency and support circular economy principles.
Under ATIEL’s transition framework, Issue 24 of the Code will remain available as the reference document for valid claims against ACEA 2022 heavy-duty engine oil sequences until Oct. 1, 2026. Issue 25 was introduced primarily to incorporate ACEA 2024 heavy-duty engine oil sequences and did not materially change requirements affecting claims made under earlier ACEA specifications, the association said.
ATIEL said the latest update responds to changes in the technical, regulatory, and sustainability landscape facing the European lubricants industry. “The inclusion of re-refined base stocks reflects changes in technical, regulatory and sustainability expectations facing the European lubricants industry,” the association said, adding that the revision aligns with efforts to improve resource efficiency in engine oil formulation and marketing.
The Code of Practice, first established in 1996, was developed jointly by ATIEL, the European Automobile Manufacturers’ Association, and the Additives Technical Committee and forms part of the European Engine Lubricants Quality Management System, which governs engine oil performance claims in Europe. ATIEL said Issue 26 is available through its website and is intended to provide consistent guidance for lubricant developers, manufacturers, and marketers while maintaining performance and quality standards expected by vehicle manufacturers, regulators, and end users.