‘Little lungs are paying’: 1.6m claimants head to high court as carmakers finally face punishment for Dieselgate
“Little lungs are still paying for Dieselgate every day,” says Jemima Hartshorn, the founder of the Mums for Lungs campaign group. Her own young daughter has suffered serious breathing problems, which at their worst involved the harrowing experience of having to pin her to the floor to administer an inhaler. It is 10 years since the scandal erupted, exposing cars that pumped out far more toxic fumes on the road than when passing regulatory tests in the lab. But Dieselgate is far from over. The excess pollution emitted has already killed about 16,000 people in the UK and caused 30,000 cases of asthma in children, experts have estimated. A further 6,000 early deaths will occur in coming years without action, they say. That action is taking an “outrageous” amount of time, say lawyers, leaving more than a million of the dirty diesels still on the road today. Unlike countries such as the US and Germany, the UK government has yet to fine any car manufacturer, or force them to recall and repair their vehicles. Instead, owners have had to seek justice by mounting the largest group action claim in English legal history, with 1.6 million claimants represented in a high court trial that starts on Monday. “I want the alleged deception of these manufacturers to be brought into the open and for them to be held to account,” says Adam Kamenetzky, from south London and one of the claimants. When buying a car in 2018 before the birth of his twin children, he chose his 2013 Mercedes ML250 specifically because of its low emissions in official tests. Now he says he feels he was deceived and was contributing, unknowingly, to deadly air pollution. Court documents assessed for the Guardian, which the car companies had sought to keep confidential, reveal an extraordinary array of alleged illegal “cheat devices”. These enabled many diesel cars to sail through official tests, only for the nitrogen oxides (NOx) in their exhausts to soar when used in real-life driving. Previous reports have shown that most diesel cars sold from 2009-19 emitted more NOx on the roads than in official tests. The motivation for this deployment of engineering ingenuity was, the claimants lawyers argue, to save the car companies money and save drivers the inconvenience of having to top up tanks with AdBlue, a chemical used to reduce pollution. The carmakers deny the alleged defeat devices were illegal and say the claims against them are without merit, arguing the devices were necessary to protect the engines. A guilty verdict could see the carmakers having to pay billions of pounds in compensation, although the legal fight could take another three years to complete. Even then, while each diesel owner may receive thousands of pounds in financial compensation, judgments against the carmakers would not compel them to fix the cars. Ministers have had the legal framework needed to do this since 2021 but have yet to use it, and while 76 models are under investigation by officials, progress is agonisingly slow, say lawyers. ‘Struggling to breathe’ Concern over the impact air pollution was having, particularly on children, was the reason Hartshorn founded campaign group Mums for Lungs in 2017. But in 2022 that concern became deeply personal. “My daughter, who was three-years-old at the time, became very ill,” she wrote in a witness statement related to the group claim trial. “She was struggling to breathe and our GP advised us to go immediately to the accident and emergency department. The severity of her condition was instantly recognised by a nurse. My daughter was given inhalers and steroids and, after five hours, was eventually discharged, with daily nurse visits scheduled from the following day. “I had to administer a spacer, which is a type of inhaler, to my daughter every two hours, over the next several days. My daughter found the spacer frightening. I had to restrain her in the ‘crucifix position’, pinning her arms with my legs, in order to force her to breathe through it. This experience was gruelling and deeply upsetting for us both.” Three days later Hartshorn’s daughter was back in hospital. “It was a very frightening time,” she wrote. Thankfully, her daughter’s respiratory health has improved recently. “However, children growing up in London, Manchester and other cities and towns across this country are sick because of diesel emissions,” she told the Guardian. “It is time the car manufacturers paid as well.” Prof Nick Hopkinson, a respiratory medicine expert at Imperial College London and medical director of Asthma + Lung UK, says: “Dieselgate isn’t just a corporate scandal – it is helping to fuel a toxic air emergency that has already cut short thousands of lives, and will continue to do so without urgent action. The UK government has been too slow to act, resulting in millions of high-polluting diesel vehicles remaining on our roads.” ‘Still pumping out NOx’ The car companies on trial have made the vast majority of cars on the UK’s roads, but the colossal scale of the case means the court has chosen five lead defendants to go first: Mercedes, Ford, Peugeot/Citroën, Renault and Nissan. Nine more companies face similar claims of using illegal defeat devices, including Vauxhall, Volkswagen, Jaguar Land Rover, BMW, Fiat, Hyundai-Kia and Toyota. These cases will be considered in the light of the result of the first trial. Benjamin Croft, a partner at Leigh Day, one of the two law firms leading the case, sets out the claim: “Firstly, the claimants’ case is that these drivers were deceived into buying vehicles that were marketed as conforming with the legislation and being environmentally friendly and not pumping out NOx that is harmful to human health.” “The second point is that the expert evidence shows that these vehicles are still pumping out far more NOx than they should, and people’s health is being affected by it.” At the heart of the case are the alleged illegal defeat devices. Diesel car manufacturers had developed sophisticated technology to reduce NOx emissions. But, the lawyers argue, they deployed equally sophisticated ways to ramp the technology up when the cars were undergoing the official emissions test then ramp it down during normal driving on the road. This was possible because the test involved a fixed sequence of gentle accelerations, steady travel and braking, highly unlikely during real-world driving, and were conducted on rollers under strictly controlled laboratory conditions. When a car’s onboard computer spotted it was undergoing the test, it ramped up NOx control, cutting emissions. (A more realistic test, including on-the-road emissions testing, started to be introduced in 2019.) The court documents allege that the five manufacturers used dozens of single defeat devices between them. As well as the characteristic test pattern, documents say the vehicles used multiple other factors to identify the test conditions: the ambient temperature being outside the test requirement of 20C to 30C, engine torque being higher than needed in the gentle test, and even the atmospheric air pressure, which was also a test requirement. When test conditions were detected, the cars then adjusted the NOx control systems. One alleged illegal cheat device was cutting the recirculation of exhaust gas into the engine, which reduces the combustion temperature and lowers NOx production. Another affected the lean NOx trap, a unit that absorbs NOx like a sponge. Here the alleged illegal cheat device would purge the unit during the prescribed warm-up before the regulatory test, ensuring optimum performance during the test. The third major category of alleged cheat device altered the most effective NOx control of all: selective catalytic reduction (SCR). This works by injecting urea – sold as AdBlue – into the exhaust stream, but was reduced outside test conditions, the court documents say. BMW, Volkswagen and Daimler were fined €875m in 2021 by the European Commission for cartel conduct that restricted competition in SCR use. Cost and inconvenience The obvious question is why did the carmakers go to such trouble to allegedly cheat the NOx emissions test? “We say the automakers had the technology to limit NOx to legal levels but chose not to deploy it and instead used their expertise to prioritise cutting costs and inconvenience, eg. Ad Blu refills, for themselves and the drivers of their cars,” says Croft. Some carmakers have voluntarily recalled vehicles to install updates they say reduce NOx emissions. But these are problematic, say experts, and only cover a small fraction of polluting vehicles. “There’s no easily accessible central database that we can search,” says Emily Kearsey, a lawyer at Client Earth, which has made three legal complaints about diesel NOx emissions to the UK government since 2023.“ So it’s incredibly difficult to get any sense of what is the actual fix? What is the timeline? What is the actual percentage of vehicles that have been fixed?” Yoann Bernard, of the International Council on Clean Transportation (ICCT), the group that first exposed the Dieselgate scandal, says doubts also exist about the effectiveness of some of the software updates after the EU Joint Research Centre tested some updated vehicles and found no improvement in emissions. Bernard adds that Renault, for example, has said its software updates have no impact on vehicle performance or fuel consumption: “If manufacturers possessed a software solution capable of reducing NOx emissions without adversely affecting fuel consumption and performance, why was it not implemented from the outset rather than risking a scandal?” The carmakers largely accept that the vehicles operate as the claimants allege but say the alleged defeat devices are in fact legal technologies, in some cases necessary to protect car engines from damage and issues such as the build up of soot. They say the claims against them are unfounded and that the companies will robustly defend themselves in court. “In our opinion, the emission control software functionalities in question are justifiable from a technical and legal standpoint,” said a spokesperson for Mercedes. The company has rolled out voluntary software updates shown to be effective at reducing NOx emissions by 25-30%, she said, adding: “As a responsible vehicle manufacturer, we continue to take steps to mitigate the impact of vehicle emissions and to further climate protection and air quality.” “All Renault’s vehicles were type approved in accordance with the regulatory requirements applicable at the time,” a company spokesperson says. A spokesperson for Peugeot/Citroën’s parent company said: “Stellantis firmly believes that its vehicles and engines fully comply with all applicable emission regulations.” A spokesperson for Nissan said the company is committed to compliance in all markets and supportive of the evolution of emissions testing regimes and standards over time. Ford did not respond to a request for comment. Rulings by the court of justice of the EU since 2020 ruled that defeat devices that operate most of the time are not legal and, in any case, are only permitted if required to prevent extremely serious damage. The ICCT has continued to track the diesel emissions polluting Europe’s air and says there are still more than 1.3m diesel vehicles with “extreme” emissions of toxic pollution on the roads of the UK today, with a further 10m on EU roads. Extreme means at least three times over the official NOx limit for the cars, which were sold from 2009 to 2019. “The issue therefore remains unresolved,” says Bernard. ‘Huge deal’ Some countries have held carmakers to account for Dieselgate. VW was the first company to be exposed and was hammered by the US Department of Justice. In 2016, the DoJ forced VW to pay about $10bn compensating drivers and $5bn to support electric cars and cut air pollution, as well as compelling the recall and fixing of the dirty diesels. German prosecutors fined VW €1bn in 2018, and by 2020 the company said the scandal had cost it $34bn. Smaller fines have been imposed in Italy, the Netherlands and Poland. In the UK, VW settled a 2022 court case brought by 91,000 drivers by agreeing to pay them £193m, about £2,100 each. But the British government has yet to punish any car company. “Auto manufacturers have been trying to sweep the Dieselgate scandal under the carpet for too long,” says Kearsey. “[The group claim trial] is a huge deal and a very important part of securing justice for people who feel they were misled. But we are working in parallel to try to ensure the government takes the action it needs to ensure that these cars are taken off the roads. Even if the manufacturers are found guilty of wrongdoing and there is compensation for consumers, it wouldn’t necessarily result in the cars being fixed and the air being cleaned up.” The UK government has had the power since 2021 to implement laws allowing them to compel recalls. But it has yet to use that power, despite saying in 2023: “Abuse of the system is not acceptable – we are looking to bring forward stronger powers.” It is investigating 76 models of car. “These investigations seem to be taking longer than they should, especially given the gravity of the issue,” Kearsey says. A spokesperson for the Department for Transport said: “We acted quickly to set up an investigation into defeat devices. We are now considering what action we could take should manufacturers be found to be breaking the rules.” While the three-month group claim trial begins on Monday, there is a long road ahead. Final submissions in the trial are due in March 2026, with a judgment expected next summer. If the claimants win, then another trial to determine how much the carmakers will have to pay is listed for autumn 2026. There may even be further legal wrangling, such as whether a time limit could rule out the oldest vehicles. Kearsey says: “It’s hugely frustrating and outrageous when you see the wealth of evidence over the past 10 years that strongly indicates that the original VW scandal was just the tip of the iceberg. [The damage to health] is shocking, really affecting people’s lives now, and it will do so into the future until action is taken.” Kamenetzky, a Mercedes driver, says he is determined to see the case through: “I’m not in this for a payout. I’m just staggered by the level of injustice.”