The United Kingdom’s lubricant specification watchdog has prompted a series of product withdrawals, claim revisions and label changes as it continues a market-wide review of engine oils claiming compliance with Stellantis’ FPW 9.55535/03 specification.
Verification of Lubricant Specifications (VLS), an body that investigates lubricant product complaints, launched the probe in 2025 amid growing use of the specification across Stellantis passenger cars and light commercial vehicles.
The requirement applies to a range of Peugeot, Citroën, DS, Fiat, Vauxhall, Opel and Jeep models, particularly those fitted with DV5R, DW10F and DW12RU diesel engines and 1.2-liter PureTech gasoline engines.
The specification was introduced in 2023 to address reliability concerns linked to wet timing belt systems, where lubricant chemistry plays a critical role in preventing belt degradation and debris formation that can block oil strainers. Three versions of the specification have since been released, with version one issued in July 2023, version two in June 2024 and version three in March 2026. Only four oils were originally approved against version one, supplied by TotalEnergies, Castrol, ExxonMobil and Stellantis.
Among the products affected by the investigation, Smith & Allan agreed to suspend sales of its Momentum C3 SWTL 5W-30 and remove it from its catalog pending formal approval of its additive package against the Stellantis requirement. Claims for Mannol Energy Formula PSA 5W-30 7703 were withdrawn after the marketer was unable to provide supporting evidence, while Ravenol removed the specification claim for its SMP SAE 5W-30 product from its website.
Other marketers and blenders have revised product documentation rather than withdraw claims entirely. Aztec Oils amended its Torotec 5W-30 STL claim to clarify that it relates specifically to version one of the specification.
Similar changes were agreed for Independent Motor Trade Factors Association’s Ad Tec 48 5W-30 PCEO, Rapid Group’s Pro + Power Ultra 5W-30 PCEO and Granville Oil & Chemical’s Hypalube FS-ST 5W-30 PCEO, with labels and technical data sheets updated to reference version one.
All of the cases will be reviewed again within six months. VLS noted that claims against version one are expected to remain valid only until July 2026, after which products must comply with version two. Stellantis has not yet clarified how long claims against version three will remain valid.
“The majority of claims are valid,” VLS Chairman Darren Frogson said, but added that the investigation has demonstrated the need for independent verification to ensure workshops and vehicle owners can rely on lubricant performance claims.