The history of the diesel emissions scandal

Close-up of the exhaust pipe of a black car with white clouds of emission fumes coming out.

The diesel emissions scandal, also known as “dieselgate”, has rocked the automotive industry over the past few years. The scandal revealed that several car manufacturers had been cheating on emissions tests, resulting in higher-than-allowed levels of harmful pollutants being released into the environment.

In this article, we look at the timeline of the key events that unfolded in the diesel emissions scandal.

The diesel emissions scandal timeline


Volkswagen (VW) installs “defeat devices” in diesel engines that cheat emissions tests in Europe and the US.


Researchers from West Virginia University (WVU) publish a study that shows VW’s diesel cars emit up to 40 times more nitrogen oxide (NOx) than allowed by US regulations.


The US Environmental Protection Agency (EPA) launches an investigation into VW’s emissions cheating. VW admits to installing software, known as a “defeat device”, in its diesel cars. This device could detect when the car was undergoing emissions tests and adjust its performance to meet the standards. However, during normal driving, the cars emitted much higher levels of NOx.

The US Department of Justice files a lawsuit against VW under the Clean Air Act, seeking billions of dollars in fines.

VW announces a recall of millions of diesel cars worldwide to remove the defeat device.

VW admits that the emissions cheating affects around 11 million vehicles worldwide, including Audi, Porsche, and Skoda models.


The UK’s Department for Transport (DfT) launches an investigation into diesel emissions, focusing on VW.

VW agrees to pay $14.7 billion to settle the civil and environmental claims against it in the US.

The European Union launches legal action against the UK and six other EU countries for failing to address air pollution.


The UK High Court rules that the government failed to take appropriate action to address air pollution in the country.

VW is fined $4.3 billion by US regulators and pleads guilty to three criminal charges related to emissions cheating.

The European Union introduces new emissions testing procedures for vehicles, known as the Worldwide Harmonised Light Vehicle Test Procedure (WLTP).



The European Commission fined BMW, Daimler, and VW a total of €875 million for colluding to limit the development of emissions-reducing technology.


VW announces that it will pay €830 million to settle a class-action lawsuit brought by German customers affected by the emissions scandal.



VW settles a group litigation claim in the UK for £193 million to more than 90,000 drivers, and appologised to its customers.

Lanier, Longstaff, Hedar & Roberts LLP launch the Renault diesel emissions claim, on behalf of the affected vehicle owners in England and Wales.

Have other car manufacturers been suspected of cheating on diesel emissions tests?

Whilst VW may have been at the centre of the diesel emissions scandal, it’s not the only manufacturer suspected of cheating emissions tests. Here are some of the other car manufacturers that have faced similar allegations:

Renault: In 2017, French authorities raided Renault’s offices as part of an investigation into possible emissions cheating. Renault denied any wrongdoing but agreed to recall 15,000 diesel cars and make technical changes to them to reduce their emissions.

General Motors (GM): In May 2017, a lawsuit was filed against GM, accusing the car manufacturer of installing emissions-cheating software in its diesel trucks. GM denied the allegations, but the lawsuit is ongoing.

Daimler: In 2018, the German government ordered Daimler to recall 774,000 diesel vehicles after finding that they contained illegal emissions software. Daimler denied any wrongdoing but agreed to pay an €870 million fine in 2019 to settle the matter.

Mercedes-Benz: In 2019, the German government ordered Mercedes-Benz to recall over 700,000 diesel vehicles after finding that they contained illegal emissions software. Mercedes-Benz denied any wrongdoing but agreed to pay an €870 million fine in 2020 to settle the matter.

Fiat Chrysler Automobiles (FCA): In 2019, FCA agreed to pay $800 million to settle claims that it installed software in its diesel vehicles that allowed them to cheat emissions tests. The settlement included $311 million in penalties and $500 million in compensation to owners of affected vehicles.

As the diesel emissions scandal and its aftermath continue to unfold, it has become clear that the automotive industry has a long way to go in terms of reducing emissions and improving air quality.

Whilst some automakers have been caught cheating, others are investing in new technologies, such as electric vehicles and hydrogen fuel cells, to reduce their environmental impact. As customers become more aware of the issue, they’re also demanding cleaner and more sustainable transportation options.

Why is the diesel emissions scandal an issue?

The diesel emissions scandal is an issue because it’s had a significant impact on public health and the environment. Diesel engines are a major source of air pollution, particularly in urban areas, and the use of defeat devices has allowed car manufacturers to emit higher levels of harmful pollutants than they claim. These pollutants can have serious health impacts, particularly for vulnerable groups such as children and the elderly. Additionally, air pollution contributes to climate change, and the use of defeat devices has led to higher greenhouse gas emissions than would have been reported otherwise.

The scandal has also eroded public trust in the automotive industry and regulatory bodies, and has highlighted the need for greater transparency and accountability in emissions testing and regulation.

How have Renault owners reacted to the diesel emissions scandal?

An estimated one million car owners are likely to be affected by the Renault emissions scandal. Since the launch of our claim at the end of 2022, we’ve received high interest from Renault owners wanting to join the claim, and hold the car giant accountable for its actions.

They were mis-sold what was thought to be an environmentally friendly vehicle, only to find out it may actually be causing more damage.

Also, due to the defeat device, the car may have decreased in value and cost more in fuel, repairs and maintenance. As a result, our clients have been left feeling outraged by the actions of Renault and are seeking compensation for the harm caused.

Contact us

We believe car manufacturers should be held to account for their part in the diesel emissions scandal and that’s why we’ve launched the Renault emissions claim.

We have extensive experience in successfully representing consumers in large-scale group action claims, including in relation to emissions. As a result, our lawyers have secured substantial awards of compensation for consumers who’ve been wronged.

Simply click the button below to join the claim or visit our Renault claim FAQs to find out more.