Key facts
- Carmakers broadly won the first stage of UK lawsuits alleging prohibited "defeat devices" in diesel vehicles.
- Judge Sara Cockerill rejected most principal allegations against Mercedes-Benz, Ford, Nissan, Renault, and Stellantis.
- The trial focused on 20 sample vehicles from the five defendant manufacturers.
- The court found that technology and strategies used in some Mercedes and Peugeot-Citroën cars could constitute defeat devices.
- Lawyers for the claimants are considering an appeal, citing a divergence from European legal interpretations.
Carmakers have largely welcomed a UK High Court verdict that rejected most allegations in a "dieselgate" claim brought on behalf of 1.6 million UK owners of polluting cars. Lady Justice Cockerill stated that "in the majority of instances, the court found that the relevant strategy did not constitute a prohibited defeat device," which is software that enables an engine to behave differently in tests. However, she noted that technology and strategies used in some Mercedes and Peugeot-Citroën cars could constitute defeat devices.
The claimants had argued that manufacturers had engineered vehicles with technology that would reduce nitrogen oxide (NOx) emissions in tests compared with normal driving conditions, while manufacturers denied using prohibited defeat devices. The case, which focused on 20 vehicles sold by Mercedes, Ford, Renault, Nissan and Peugeot/Citroën from 2009, is the largest group action trial in English legal history.
Lawyers for the claimants indicated they were considering an appeal, highlighting a significant divergence between the legal position in Great Britain and much of Europe. Mercedes-Benz and Stellantis (owner of Peugeot-Citroën) are considering appeals over the specific vehicles deemed non-compliant, while Nissan and Renault welcomed the ruling, asserting their vehicles comply with all regulatory requirements.