A High Court judge has delivered a significant ruling today, determining that the majority of major car manufacturers involved in a mass legal action did not equip their vehicles with devices designed to manipulate emissions tests. The judgment comes after a ten-week trial examining claims from approximately 1.6 million motorists who alleged they were misled about the environmental performance of their diesel cars.
Lady Justice Cockerill's extensive 369-page ruling concluded that most of the emissions control strategies employed by the carmakers did not constitute "prohibited defeat devices" (PDDs). The court specifically investigated 20 sample vehicles produced by five manufacturers: Mercedes-Benz, Renault, Nissan, Ford, and Peugeot and Citroen. A notable exception was identified in certain Mercedes cars, where a device was found but subsequently removed in 2015, and another in some Peugeot-Citroën vehicles.
The legal action, primarily brought by motorists in England and Wales, contended that the devices allowed vehicles to detect when they were undergoing official emissions tests, altering their output of harmful emissions to meet regulatory standards. However, the court clarified that not every calibration or emissions-control strategy amounted to a defeat device. The judge emphasised that for a device to be classified as prohibited, there needed to be an intention to cause the emissions control system to operate differently during testing conditions.
Mercedes-Benz has welcomed the overall ruling but expressed disagreement with the court's finding regarding one of its four sample vehicles, asserting that its emission control software functionalities are justifiable on both technical and legal grounds. The German carmaker is now actively considering all available options, including a potential appeal. Peugeot-Citroën has yet to issue a public statement following the judgement.
While the ruling largely sided with the manufacturers in this initial phase, solicitors representing the claimants noted that Lady Justice Cockerill indicated that a different interpretation of "defeat device" could have led to a greater number of devices being established across all lead manufacturers' cars. The wider legal case involves models from several other manufacturers, including Opel and Vauxhall, Volkswagen and Porsche, Jaguar Land Rover, BMW, FCA and Suzuki, Volvo, Hyundai-Kia, Toyota and Mazda, whose vehicles were not part of this initial sample.