According to CNBC, London's High Court began hearing one of the largest mass lawsuits in English legal history on Monday, October 13, 2025. Lawyers representing 1.6 million claimants accuse Mercedes-Benz, Ford, Nissan, Renault and Stellantis-owned brands Peugeot and Citroen of cheating diesel emissions tests. The claimants allege these manufacturers installed unlawful defeat devices in diesel vehicles produced between 2012 and 2017.

The devices allegedly detected when vehicles underwent testing and ensured nitrogen oxide emissions stayed within legal limits. However, lawyers say emissions rose far higher during regular road use, in some cases reaching 12 times test limits. The trial will examine 20 sample vehicles from the five manufacturers over three months. All accused companies deny wrongdoing and reject comparisons to Volkswagen's 2015 scandal.

Why This Matters

The trial's outcome could determine compensation for hundreds of thousands of vehicle owners who paid premiums for supposedly cleaner diesel cars. Claimants argue they were misled about their vehicles' environmental impact when making purchase decisions. One claimant, Adam Kamenetzky, told media he bought a Mercedes SUV in 2018 believing it was less polluting than other models.

The current litigation involves claims against 14 manufacturers total, with claimants' lawyers valuing the case at approximately 6 billion pounds. The court will first decide liability before any compensation phase begins in 2026. Mercedes-Benz told media that its emissions control systems were based on technical needs and remain legally justified. Ford stated the claims have no merit. This trial follows a 2020 ruling against Volkswagen, which settled similar claims for 193 million pounds without admitting liability in 2022.

Industry Implications

The case arrives a decade after Volkswagen admitted installing defeat devices, which led to the company paying over 32 billion euros in fines, penalties and compensation globally, according to Wikipedia. Former Volkswagen CEO Martin Winterkorn faced criminal charges, though his trial was suspended on health grounds in October 2025. The scandal reshaped the global automotive industry and accelerated the shift toward electric vehicles.

Automakers face similar litigation worldwide. In July 2025, a Dutch court ruled that diesel cars sold by Stellantis brands contained defeat devices, a ruling Stellantis disputes. Manufacturers have paid fines and reached settlements in the United States and elsewhere to resolve diesel emissions investigations. The International Council on Clean Transportation estimates 16 million diesel vehicles in Europe currently show suspicious emission levels, with 11 million showing extreme levels.

Research indicates nitrogen oxide emissions from excess diesel pollution may cause 205,000 premature deaths across the EU and UK between 2009 and 2040. The economic burden of these health impacts equals 760 billion euros. This trial could establish precedents affecting global emissions litigation and regulatory enforcement. The automotive sector continues facing pressure to meet stricter environmental standards while managing legal risks from past diesel practices.

Further Reading

For deeper insights into global automotive regulatory trends and compliance frameworks, our Alternative Financial Systems Index tracks policy developments and enforcement patterns across 50 countries. The resource provides data on how governments approach corporate accountability in emerging technology sectors.