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Dieselgate Scandal Explained – 2024

Author: Samuel Beckingham
Updated: Mar 08, 2024
9 minutes read
  • Complete timeline of the dieselgate scandal
  • How Volkswagen sent ripples throughout the automotive world
  • Make a claim for being mis-sold

Even though the effects of the dieselgate scandal are still being felt today, the initial case came to light back in 2015. Since then, vehicle manufacturers have been under intense scrutiny for their involvement in similar practices. It’s all to do with making diesel emissions appear better than real-world conditions. This gives you grounds to make a diesel claim.

This article will explore the complete timeline surrounding the VW dieselgate scandal. It will go into various evidence that came to light at different stages, and what happened as a result.

Ready to start your diesel claim? Use our eligibility checker to see if you qualify. It only takes a minute.

The Volkswagen logo bookended by a diesel pump and an exhaust pipe

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The Dieselgate Emissions Scandal In a Nutshell

Put simply, Volkswagen was discovered to have installed defeat devices within some of their diesel vehicles. These cheated emissions tests as the car would recognise when it was being tested, and limit its output accordingly. When anyone refers to the dieselgate scandal, this is what they mean.

Original tests revealed that some engines were capable of emitting more than 40 times the legal limit, despite passing lab tests. In other words, they were much worse on the roads than previously thought.

The dangers of nitrous oxides (NOₓ), carbon monoxide (CO) and carbon dioxide (CO₂) are well documented. Increased levels of these gases means consumers were misinformed, making a claim possible.

Dieselgate Scandal Timeline

2014 – Inconsistencies First Noted


The International Council on Clean Transportation (ICCT) wanted to perform tests on diesel vehicles in America to demonstrate that clean diesel was possible. The country had much stricter emissions laws more rigorously enforced, so they wanted to find a good benchmark to work from.

At the time, it was noted how VW vehicles routinely passed these tests with no issue. Hoping to find a control model for tests with other manufacturers, the ICCT enlisted the help of West Virginia University’s Center for Alternative Fuels, Engines and Emissions (CAFEE) to perform real-world tests.

At first, the high levels of NOₓ detected by the portable tests for the Jetta and Passat models were put down to errors on their part. Emissions standards were exceeded by 15–35 times for the Jetta and 5–20 times for the Passat [1]. However, after double and triple checking their work, it was clear there was an underlying issue with the vehicles.

According to the testers for real-world conditions, there was a defeat device located in the software of these vehicles. It was deemed to be very sophisticated and imperceptible to even the most attuned driver.

2014 – Volkswagen Notified and Later Admit Liability

Clipboard Checks Vector

In May, the data was sent to the appropriate bodies and Volkswagen. This was the start of VW’s attempts to replicate the results found by the university to keep the dieselgate scandal hidden. Despite recalling 500,000 diesel vehicles in December for a software patch as a supposed fix, this didn’t rectify the issue. Real-world tests continued to show results that exceed legal limits.

The ongoing investigations landed the manufacturer in hot water. VW was told that certification for some 2016 diesel models would not be granted on account of unanswered questions [2]. Considering American sales of Volkswagen’s diesel vehicles were estimated to be ¼ of their total, they were backed into a corner [3].

This is when VW admitted it had intentionally fitted a ‘sophisticated software algorithm’ that allowed diesel vehicles to reduce NOₓ emissions during the testing phase.

2015 – The Birth of the Dieselgate Scandal

The Environmental Protection Agency (EPA) estimated that illegal defeat devices were installed in more than 600,000 vehicles throughout America [4]. Not only this, but millions of diesels around the world would be affected.

Volkswagen tried to downplay the severity of the situation, initially saying that none of their European models were affected. This later evolved into ‘irregularities’ in 800,000 cars in Europe, before becoming an issue for 36,000 of its cars produced a year [5]. This meant the dieselgate scandal in the UK was just coming to light.

We now know that the software was deployed in around 11 million VW cars worldwide, from models manufactured between 2009 and 2015 [6]. Companies that could process your diesel claim started to appear.

2015 – Global Coverage

Findings Vector

In September, the EPA came forward about VW violating the Clean Air Act through the use of its illegal software [7]. Regulators in different countries started to investigate, and the dieselgate scandal exploded in the news.

  • It was reported that at least 30 people at management level within VW had known about the deceit for years

  • The CEO of Volkswagen, Martin Winterkorn, resigned

  • The share price of VW fell by a third overnight

  • Shareholders and customers felt cheated

British researchers compared data to vehicles in similar tests. They found illegally high levels of emissions in BMW, Ford and Mercedes vehicles. Some small cars were even producing more gases than a double decker bus [8].

2016 – US Courts

In April, Volkswagen announced plans to spend €16.2 billion in reparations in the US market. By June, the vehicle manufacturer agreed to pay up to $14.7 billion for civil charges [9].

By this time, various bodies around the world were looking into how other manufacturers might also be implicated in the dieselgate scandal.

Kraftfahrt-Bundesamt (KBA) performed an investigation into thermal windows. This was originally designed to help protect the engine in colder weather. KBA found that there was no uniform temperature across carmakers, with some making use of them at 18°C [10].

2017 – Pleading Guilty


Back to the VW dieselgate scandal, January was when they pleaded guilty to criminal charges. A Statement of Facts was drawn up to reveal how defeat devices were developed and concealed.

In April, VW was ordered to pay a $2.8 billion criminal fine [11].

At the same time, the Federal Ministry of Transport and Digital Infrastructure (BMVI) investigated emissions controls across the industry. Their findings concluded that most manufacturers were adjusting the efficiency of them, either by abusing thermal windows or unknown means [12].

2017 – Emissions Testing

Deutsche Umwelthilfe Logo

Across all manufacturers, pressure started to mount. The dieselgate emissions scandal was being investigated by more and more bodies.

In December, Deutsche Umwelthilfe (DUH) performed tests on BMWs. The German Environmental Aid found that a BMW diesel can be up to 7.2 times more polluting than legally permitted levels [13].

2017 – Collusion

In a similar vein, several carmakers were trying to limit the erosion of their profits. In the midst of the dieselgate scandal, shady corporate schemes were in the works.

BMW, Mercedes and VW were all investigated in Germany over colluding about diesel emissions limits. For trying to limit the adoption of clean energy technology, they were fined a collective £750 million [14].

2017 – European Emissions

Back on topic, more fuel was being added to the fire of the dieselgate scandal.

In September, the ICCT compared the emissions of 541 diesel vehicles across 145 European models. According to their findings, 74% of cars exceeded NOₓ and CO₂ limits [15].

2018 – High Real-World Emissions


Three years on from the initial findings of the dieselgate scandal, The Real Urban Emissions Initiative (TRUE) looked into several manufacturers to discover how emissions levels had been impacted.

Volvo diesel vehicles were found to be 3.43 times more polluting than their petrol equivalents. However, every manufacturer’s diesel models exceeded laboratory results [16].

Martin Winterkorn was charged with fraud and conspiracy in America.

2018 – BMW Raid

Investigators raided BMW for emissions cheating software. The vehicle manufacturer admitted this had happened, but only by accident. They said it was ‘correctly developed software’ that had been allocated to models it wasn’t suited to ‘in error’.

11,400 BMW diesels were recalled as a result of the raid for fears over involvement in their own dieselgate scandal [17].

2019 – Australian Case

Despite the Australian Competition and Consumer Commission stating it wouldn’t investigate emissions standards for Volkswagen in 2015, the dieselgate scandal still reached their shores.

In December, VW was fined AU$125 million for false and misleading representations in compliance with emissions standards [18].

2020 – Widespread Use

The DUH found evidence for illegal shutdown devices during exhaust gas measurements in diesel vehicles. They discovered Volvo’s exterior mirror contained a temperature sensor. It was only later that the manufacturer admitted this [19].

At this point, the dieselgate scandal had cost VW $33.3 billion in fines, settlements, and various other related costs.

2020 – Thermal Window Abuse Illegal


The European Court of Justice ruled the thermal window is its own defeat device. It deemed them acceptable only when protecting against sudden and extraordinary damage. The dieselgate scandal represented widespread misuse of them [20].

2021 – Mercedes E-Class

Having remained fairly unaffected so far, the dieselgate scandal and Mercedes start to mix.

The DUH accused Mercedes of using eight defeat devices across E-Class models. Any diesel with the OM642 engine reduced the amount of AdBlue used, which is meant to eliminate NOₓ emissions [21].

2022 – UK Settlement for VW Dieselgate Scandal

A group litigation order (GLO) was supposed to go to the English courts in early 2023. Instead, VW reached an out-of-court settlement in May 2022.

More than 91,000 claimants received a share of £193 million in compensation for VW’s involvement in the dieselgate scandal. By settling early, the car manufacturer avoided admitting liability [22].

2023 – European Emissions Retested

KBA Logo

Almost 10 years on from the initial discrepancies found in Volkswagen vehicles, tests were conducted to see if the dieselgate scandal had reduced real-world emissions.

In March, the ICCT reassessed excess emissions in European cars. It found that suspicious levels of NOₓ emissions were present in 77–100% of tests. Extreme levels were reported in 40–75% of tests and vehicle averages [23].

In July, KBA revealed that Mercedes had been utilising software cheating devices in some of its engines. Mercedes pointed out that it had rolled out software updates to fix the issue.

2023 – High Court Hearing

In December, a preliminary hearing at the High Court proposed combining claims against manufacturers as a result of the dieselgate scandal. Claims against Mercedes, Ford and one or two other carmakers would be grouped together [24].

Unless an agreement is reached outside of court, this is scheduled to go ahead in February 2025.

The Dieselgate Scandal Is Far From Over

As you can see, the evidence against manufacturers has been mounting for years. This only scratches the surface of the full dieselgate scandal, as not all evidence is on this page. We’ve also only covered events in several countries.

Make a Diesel Emissions Claim

If you’ve ever owned a diesel vehicle, there’s a high probability that your manufacturer was involved in the dieselgate scandal. The effects are still being seen today, especially as more data is found year after year.

If any of the following applies, you can make a diesel emissions claim:

  • You were the registered owner of a diesel vehicle between 2009 and 2020

  • The vehicle was either bought outright, financed or leased

  • It was new or second hand

  • It was a company car in your name

Hold manufacturers to account for their involvement in the dieselgate scandal by making a claim. You can check your eligibility by using the button below.


























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