Leaked Memo Detailing How Mercedes Was Recently Caught Cheating Emissions Standards Shows That The ‘Dieselgate Saga’ Continues

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The 2015 “Dieselgate” scandal rocked the automotive world and highlighted how much the industry's foundations rest on petrol and internal combustion engines (ICEs.)

What Is “Dieselgate?”

Several car companies were caught using technology to cheat emissions tests back in 2015. Part of what made this scandal so alarming is how heavily these companies were advertising their “clean diesel” vehicles as alternatives to hybrids or electric vehicles (EVs.)

This technology, referred to as “defeat devices,” works because the vehicle's software senses when it's operated under emissions testing circumstances and switches into test mode. While in test mode, the vehicle's injection timing, fuel pressure, and exhaust gas recirculation are significantly tampered down to meet the Environmental Protection Agency's emission drive cycle parameters.

While not testing, the vehicle's computer switches to regular driving mode to operate with improved power and gas mileage, causing the car to emit higher levels of the pollutant nitrogen-oxide (NOx), which studies have linked to lung cancer.

In some cases, “defeat devices” allowed cars to pass the EPA's emissions test even though the vehicle produced more than 40 times the legal amount of NOx. It should be noted that there were also plenty of cars, only a few times over the limit. The total amount of NOx a vehicle emits can be affected by load management and driving style.

The Offenders.

Volkswagen was a particularly egregious offender, installing these “defeat devices” in over 10 million cars worldwide.

More recently, Mercedes-Benz allegedly used these devices to pass Euro emission standards tests, according to Deutsche Umwelthilfe (DUH), a German environmental consumer protection group.

The particular culprit in this case is Mercedes-Benz's E350 BlueTec, which uses concealed software devices to manipulate the temperature of its OM642 diesel engine to meet emission standards.

This information comes from an anonymous whistleblower reportedly leaking a memo from the German Federal Motor Transport Authority to Mercedes-Benz, iterating that they had until July 27th to fix their software to comply with European law. However, Mercedes has since received an extension to correct these issues.

If Mercedez fails to comply, its diesel vehicles will be recalled and prohibited from operating.

The normally esteemed German automaker looks especially bad in this situation because the European Court of Justice ruled it illegal to install software-based “defeat devices” into any vehicle over a year ago.

It's not the first time Mercedez has been caught with its hand in the cookie jar, so to speak; in 2021, the DUH reported that Mercedes E-Class diesel vehicles were using eight “defeat devices” to pass as Euro 6 compliant.

Dailmer, a Mercedes parent company, settled and paid almost 3 billion dollars worth of claims in the U.S. due to a class action lawsuit and EPA, California Air Resources Board, and Department of Justice violations in 2020.

Other offenders include Former Audi CEO Rupert Stadler, who paid over a million euros in fines this year while confessing to his role in “dieselgate” to avoid jail time, and auto parts supplier Bosh, who paid $25 million in penalties for their role in enabling these companies to cheat emissions standards in 2022. 

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  • Expertise: automotive news, dramatic writing & cinema.  
  • Education: San Francisco State University, B.A. Cinema Production (2013), San Francisco State University, M.F.A. Creative Writing (2021). 
  • Feature-length play Bill & Jenna (2021) was selected for professional play development at Z Space in San Francisco.
  • Over 1,000 automotive news articles have been published on the web.      

Jarret Hendrickson is a writer. He got his start when he was accepted into San Francisco State University’s Master of Fine Arts in Creative Writing program in 2018. While earning his degree, his short plays, The Captain (2019) & Fight Night (2020), were performed at San Francisco State University's annual Fringe Festival. His feature-length play Bill & Jenna (2021) was selected for the 2020 Greenhouse Professional Play Development Workshop at Z Space in San Francisco. While studying dramatic writing and screenwriting, he concluded that Se7en is the perfect modern screenplay. He received his MFA in the fall of 2021. In addition to his interest in writing and movies, Jarret also has a long-standing interest in automotive news, which dates back to his picking up a copy of MotorTrend when he was ten. His interest in all things automotive really blossomed at age 15 when he test-drove the 1994 Volvo SE that would accompany him for the next decade. His ongoing interest in cars helped him secure his first freelance writing job when he was hired to cover automotive news for axeladdict.com, where over 1,000 of his articles were published. You can find him on X (the social media platform formally known as Twitter) @jarrethsfpa and on Linkedin. Jarret currently covers the daily ebb and flow of the automotive industry for Wealth of Geeks.