London: Five major car brands are on trial in the UK over the diesel emissions scandal, commonly referred to as ‘dieselgate.’ The class action lawsuit, involving approximately 850,000 drivers, is being heard at the High Court and is expected to continue for three months, with judgment likely to be reserved until mid-2026.
The dieselgate scandal first emerged in 2015 when Volkswagen was found to have installed defeat devices, software that gave false low emissions readings, on most of its diesel models. These devices allowed vehicles to pass emissions tests while emitting nitrogen dioxide up to 40 times above the legal limit during normal road use.
The scandal ultimately cost Volkswagen around £30 billion in fines and compensation, with the majority of payments made in the United States. In the UK, Volkswagen settled claims in May 2022, paying a total of £193 million to 91,000 vehicle owners.

The current legal action in the UK involves owners of diesel vehicles from Mercedes-Benz, Ford, Nissan, Renault, and Stellantis (the parent company of Peugeot and Citroën). These owners allege that, like Volkswagen, the manufacturers used unlawful software to ensure vehicles met emissions limits during testing while exceeding those limits in everyday driving conditions. The initial trial will focus on a small sample of vehicles produced by the five manufacturers.
Leigh Day, one of the lead solicitors’ firms handling the dieselgate case, stated that the class action is unprecedented in scale for England and Wales. The firm noted that if the case is expanded to include 14 car brands it believes violated testing rules, it could eventually cover up to 1.8 million people. In such a scenario, the claims could reach a total value of up to £6 billion.
The carmakers involved have denied all allegations. The ongoing trial underscores the continuing legal and financial repercussions of dieselgate, a scandal that first shook the automotive industry a decade ago.

