Mercedes could face £3bn bill for emissions cheating

Mercedes is being accused of installing four “defeat devices” in its diesel cars in a High Court case that threatens to be the biggest in British legal history.

A third of a million motorists are suing the German car manufacturer for allegedly deceiving them over emissions standards, which – they argue – has resulted in knocking thousands off the value of their cars. Lawyers say the claims, if successful, could be worth as much as £3 billion.

A 150-page legal claim was lodged with the High Court in London on Friday, ramping up the pressure not only on Mercedes but other manufacturers. The group action against Mercedes is the largest of its kind but will likely pave the way for further claims against other major car makers.

Mercedes has insisted the legal action is “without merit” and denies any wrongdoing.

The legal action follows the “dieselgate” scandal uncovered in 2015 in which it first emerged that Volkswagen had installed software designed to deceive official testing, reducing polluting NOx emissions in laboratory conditions that were not matched by real world driving.

‘Defeat devices’ and ‘thermal windows’

The action against Mercedes alleges that the German manufacturer had installed as many as four “defeat devices” in its diesel cars sold in the UK between 2009 and 2021.

In certain Mercedes vehicles, it is claimed that sophisticated computer software was installed that was able to detect when the car was being run through an emissions test, “triggering a change” in how the engine functioned, according to the High Court claim.

Some Mercedes were also equipped with a “thermal windows” defeat device which monitored air temperature and other factors such as altitude and air pressure which reduced emissions only under certain weather conditions.

The other alleged “defeat devices” were installed to alter the effectiveness of the emissions systems in normal driving conditions, according to the High Court claim, enabling the cars to pass the tests. The lawyers argue those systems were installed on modern, larger engined diesel cars to ensure they were compliant with Euro 5 engine standards.

The claim accuses Mercedes of installing defeat devices that “were unlawful in that they were prohibited… and had the effect that the vehicles produced far higher amounts of NOx than was permitted”.

‘It’s time for Mercedes to be honest’

Last year, Volkswagen agreed to pay £193 million to more than 90,000 car owners after settling a group claim. The Mercedes lawsuit will far exceed that due to the number of claimants and the greater value of their cars.

Martyn Day, founding partner of Leigh Day which along with another law firm Pogust Goodhead are acting as lead solicitors, said: “Talking to our clients, it is clear that the British Mercedes-owning public feel hugely let down by the manufacturer, and that is reflected by the sheer scale of people coming forward wanting to bring claims against Mercedes.

“There is a strong feeling from our clients that it is time for Mercedes to be honest, openly accept the emissions cheating allegations, pay appropriate levels of compensation and ensure that Mercedes cars in the future will be at the forefront of keeping emissions to an absolute minimum.”

The car industry has been rocked by VW’s dieselgate scandal. Lawyers operating on a no-win, no-fee basis – with adverts running on TV and in the media – have signed up about a million car owners for the various group actions.

Mercedes said in a statement: ”We believe that the claims are without merit and will vigorously defend ourselves against them or any group action with the necessary legal means.”

In a preliminary court hearing in February, lawyers for Mercedes denied liability. The lawyer said there were “crucial differences” between the cases against Mercedes and the Volkswagen litigation and that “significant care” was needed when referring to it.

Mercedes said it would show that there was no “reduction of effectiveness” in its emissions systems.