In 2025, the Verification of Lubricant Specifications (UK) Ltd (VLS), an independent and impartial body which investigates lubricant product complaints, announced a market-wide investigation into engine oils making claims against the Stellantis FPW 9.55535/03 specification,
The Stellantis FPW9.55535/03 5W 30 engine oil specification is mandated for a broad range of modern Stellantis vehicles, particularly those with DV5R, DW10F and DW12RU diesel engines, as well as 1.2L PureTech (EB2) petrol engines. It applies to many Peugeot, Citroën, DS, Fiat, Vauxhall, Opel, and Jeep passenger and light commercial vehicle models.
The specification is designed specifically for engines with “wet belts” to prevent premature wear, degradation, and the formation of debris that can clog oil strainers. Stellantis introduced it in 2023/2024 as a mandatory requirement for many vehicles to address reliability issues with wet timing belt systems and with engines fitted with external dry belts. Problems can arise if service intervals are not adhered to.
Case VLS010244 concerned the allegation that the Stellantis specification FPW9.55535/03 was being claimed for Smith & Allan Momentum C3 SWTL 5W-30, despite no widely available approved market general technology being available to support this specification claim.
VLS accepted the case and wrote to Smith & Allan, asking for the technical evidence on which the claim was based. In response, Smith & Allan stated that the claim was made on a ‘Suitable for use’ basis and no formal approval was claimed. The company agreed to pause sales of the product and withdraw it from their catalogue pending the formal approval of the market general package against the Stellantis specification.
Based on their response, VLS was content to close the investigation, subject to a six-month review, in line with its stated process.
Darren Frogson, VLS Chairman, said, “We thank Smith & Allan for their cooperation in this case and for taking positive, proactive action to pause product sales until general market technology becomes available.
As part of our market-wide investigation into engine oils claiming to meet this Stellantis specification, we have found that the majority of claims are valid. However, in some cases, claims have been removed, or products have been withdrawn.
With the lubricants sector navigating rapid change, we must have a robust, anonymous process that holds lubricant producers and marketers to account and protects end users. Workshops must have confidence that the products they select are suitable for use in the application and can deliver what they claim.”
VLS is an independent organisation that provides a credible and trusted means to verify lubricant specifications, brings transparency to the lubricant marketplace, and protects and educates end users.
