VLS reports progress on Stellantis Oil investigation
The Verification of Lubricant Specifications (VLS), an independent and impartial body investigating lubricant product complaints, has provided an update on two major strands of its work: an investigation into engine oils claiming compliance with the Stellantis FPW 9.55535/03 specification, and the closure of investigations into Silverhook products following corrective action.
In 2025, VLS launched a review of oils claiming compliance with the Stellantis FPW9.55535/03 5W-30 specification, which is mandated for numerous modern Stellantis vehicles, including those fitted with DV5R, DW10F and DW12RU diesel engines, as well as 1.2 PureTech (EB2) petrol engines.
It applies to many Peugeot, Citroën, DS, Fiat, Vauxhall, Opel and Jeep models of passenger and LCVs.
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. It was introduced by Stellantis in 2023/2024 as a mandatory requirement for many vehicles to address reliability issues with wet timing belt systems, as well as engines fitted with external dry belts. Problems can arise if service intervals are not adhered to.
Two versions of the specification have been released so far: in July 2023, Version 1 of the specification was issued, and four engine oils were approved against it from TotalEnergies, BP/Castrol, ExxonMobil and Stellantis’s own range of original engine oils. In June 2024, Version 2 of the specification was released. Oils making claims against Version 1 have until June 2026 to be reapproved.
Currently, the market contains oils claiming compliance with Version 1, while those already approved or meeting Version 1 requirements are undergoing a series of engine tests to demonstrate suitability for approval against Version 2. This approval process is expected to conclude before June 2026. Version 2 includes four additional engine simulation tests compared with Version 1.
VLS believes that market general technology to meet Version 2 is being developed so that end-users will have a choice of products that are either approved or meet the requirements of Version 2 when Version 1 is withdrawn in June 2026. There is, therefore, “some overlap” between oils making claims against Version 1 while simultaneously being submitted for testing against Version 2.
In response, VLS opened investigations into 12 engine oils. Responses from the lubricant marketers involved included updates on progress toward passing the Version 2 engine tests, prompting VLS to examine these marketing claims “more thoroughly than might otherwise be the case”. Nine cases have been closed, with most claims found valid, as they involved rebranded approved oils or formulations based on the same technology as the original four approved products.
In case VLS 010236, this was withdrawn by the marketer when challenged on evidence. The remaining investigations are expected to conclude shortly – but, at the time of writing, no update or results have been published.
Separately, VLS has closed investigations VLS 010226 and VLS 010227 after Silverhook took corrective action.
In April 2025, a batch of Silverhook Ultra-V 0W-30 PCEO was found non-compliant with SAE J300 due to excessive low-temperature pumping viscosity and yield stress. Similarly, Silverhook 0W-20 Fuel Efficient PCEO did not meet SAE J300 and ACEA C5 and C6 requirements for yield stress and apparent viscosity at -40°C.
In response, Silverhook stated it had amended the formulation prior to the VLS investigation, which would bring the product back into compliance, and these actions had been agreed with a third party. Based on the action taken and the assurances given by the third party, VLS agreed to close the investigations, subject to a standard six-month review.
VLS Chairman, Darren Frogson, said: “We would like to thank Silverhook for its positive, proactive action in this case to address product formulations. As the lubricants sector navigates rapid change in response to OEM design changes and the need to meet increasing emissions legislation, we must have a robust, anonymous process that holds lubricant producers and marketers to account and protects end users.”
