Dieselgate ruling narrows defeat-device claims

What's happened

The High Court has ruled that most testing strategies do not amount to prohibited defeat devices, narrowing a long-running lawsuit over NOx-emitting diesel cars. Mercedes-Benz faces one upheld allegation, which was removed from 2015. The ruling binds other manufacturers; a broader trial continues.

What's behind the headline?

Analysis

• The ruling narrows but does not end the dieselgate dispute in the UK, signaling a split from broader EU findings.
• The court emphasizes intent to defeat tests, warning that not every calibration is a defeat device.
• Expect appeals from Mercedes-Benz and Stellantis as the existing framework for what constitutes a defeat device is contested.
• The decision may influence future EU-UK regulatory alignment and potential damages assessments in the October trial.
• Readers should watch for how this affects consumer confidence and potential settlements across the car industry.

The legal process remains active, with a future steps including damages determination and possible further litigation across models and brands.

How we got here

The lawsuit, led by more than 20 law firms and involving 1.6 million motorists, centres on diesel vehicles from 2009 onward. The trial examined 20 vehicles across Mercedes, Renault, Nissan, Ford and Peugeot-Citroën. The decision follows a decade of scrutiny sparked by VW’s 2015 emissions scandal.

Our analysis

The Guardian reports that Justice Cockerill found most strategies did not constitute defeat devices, with exceptions in Mercedes and Peugeot-Citroën. BBC Business notes the ten-week trial and the 369-page ruling. Bloomberg provides a concise summary of the judgment and its scope.

Go deeper

• Will this lead to renewed consumer action or settlements across the industry?
• Which brands are most affected going forward and how will the October trial shape outcomes?
• How will UK law align with EU criteria on defeat devices in the near term?

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