Start with the application and exact claim
Define the equipment, viscosity grade, operating conditions, drain interval, emissions hardware and exact performance claim before selecting an RRBO. Automotive engine-oil work should identify the applicable API category, ACEA sequence and OEM requirements.
RRBO describes a feed route. It is not an additive recommendation, performance category or approval. ATIEL supports wider use while identifying possible variability from used-oil feed, segregation and manufacturing robustness.
- Separate recycled-content and performance claims.
- Check the current category and OEM documents.
- Do not create a universal RRBO content limit.
Translate base-stock data into formulation work
The candidate should be evaluated for composition, contamination, viscosity, volatility, low-temperature behaviour, inherent oxidation response and deposit tendency. The complete blend must then be considered with its additive package, viscosity modifier, pour-point depressant and other base stocks.
Residual additive elements from used oil should not be treated as useful formulation components unless identity, concentration, compatibility and performance contribution are demonstrated.
- Screen viscometry, volatility, oxidation and deposits.
- Evaluate foam, air release, homogeneity and storage stability.
- Include elastomer compatibility and application-specific performance.
Apply interchange rules and validate production
API 1509 states that base oils do not all provide equivalent engine-oil performance. Its Base Oil Interchange guidelines define minimum prudent testing for substitutions in licensed formulations, while the marketer retains responsibility for the claim.
ATIEL applies its own BOI provisions to ACEA claims and says RRBO should be treated like virgin base stock for grouping and code application. Equal treatment under the rules is not automatic equivalence or approval. Commercialisation needs read-across documentation, required testing, first-production verification, traceability and requalification after material change.
- Document every permitted read-across decision.
- Verify the first production batch against release criteria.
- Retain samples and trigger requalification after relevant change.
Read the underlying documents.
- API 1509, 24th EditionAmerican Petroleum Institute ↗
- Code of Practice, Issue 26ATIEL ↗
- ACEA Oil Sequences 2023: light-duty enginesACEA ↗
- ACEA Oil Sequences 2024: heavy-duty enginesACEA ↗
Source links and status were reviewed on 31 July 2026. Standards and regulations may be revised after publication.