Unraveling the Dieselgate Scandal: Carmakers on Trial for Emissions Cheating

A significant legal battle is underway as five major car manufacturers find themselves in a trial at the High Court in London, accused of cheating on emissions tests in a scandal that has become known as Dieselgate. The carmakers—Mercedes, Ford, Peugeot/Citroën, Renault, and Nissan—are alleged to have employed illegal software to manipulate emissions levels during testing, prioritizing customer convenience and sales over environmental compliance.

In his opening statement, Thomas De La Mare KC, representing the car owners, emphasized the conscious decision made by the industry to cheat rather than adhere to laws designed to protect air quality. He highlighted alarming findings from the Centre for Research on Energy and Clean Air, showing that excess nitrogen oxide emissions from diesel engines have been linked to 124,000 premature deaths and rising asthma cases in children across the UK and Europe from 2009 to 2024.

The defense, represented by Alexander Antelme KC for Renault, dismissed the cheating allegations as ”without merit and untenable”, arguing that the contested features of the cars were necessary components of their engines. Similarly, Ford’s Neil Moody KC criticized the claims as ”scientifically illiterate” and the notion of an industry-wide conspiracy as implausible.

The Dieselgate scandal first gained attention in September 2015 when Volkswagen was caught using ”defeat devices” to bypass emissions regulations, affecting about 11 million cars globally. As a result, Volkswagen faced hefty fines totaling approximately £26 billion, marking one of the most extensive corporate scandals in automotive history. This current class action case could potentially involve 1.6 million car owners and marks the largest of its kind in English and Welsh legal history.

Outside the court, advocates from the campaign group Mums for Lungs and relatives of pollution victims, including Rosamund Adoo-Kissi-Debrah, whose daughter was the first in the UK to have air pollution cited as a cause of death, demonstrated in support of accountability.

The court’s ruling is not expected until summer 2026, with the main trial continuing into December, although further legal arguments will not resume until March 2026. The accused companies maintain their defense, with representatives affirming that their vehicles were compliant with regulations at the time of sale. This legal saga continues to uncover the profound implications of corporate decisions on public health and environmental safety.