Major car firms found not to have emissions-cheating devices
A UK High Court judge has ruled that most major car manufacturers did not use prohibited emissions-cheating devices in their diesel vehicles. While the court found minor non-compliance in specific older models from Mercedes and Peugeot-Citroen, it rejected the majority of claims brought by 1.6 million motorists.
Why it matters
This ruling provides legal clarity for the automotive industry regarding emissions standards and impacts ongoing consumer litigation across the UK.
Image source, Getty Images By Marc Ashdown Business correspondent Published 10 July 2026 Vehicles from a host of major car manufacturers did not contain devices alleged to have allowed them to cheat on emissions tests, a judge at the High Court has ruled.
More than a dozen manufacturers are being sued by around 1.6 million motorists over claims that several diesel vehicles made from 2009 onwards contained "prohibited defeat devices" (PDDs).
The cases involved 20 "sample vehicles" made by five manufacturers: Mercedes-Benz, Renault, Nissan, Ford, and Peugeot and Citroen.
The 880,000 motorists claimed they had been misled about emissions tests.
The ten-week trial concluded in March and, in a 369-page ruling handed down today, Lady Justice Cockerill said most of the strategies did not constitute PDDs, with the exception of one in Mercedes cars that was removed in 2015, and another used in some Peugeot-Citroen vehicles.
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