Dear EarthTalk:

I heard that VW and Toyota were fined for cheating on emissions tests for new vehicles. Why did they do this and are all of the car companies likely cheating?

B.C., Boston, MA

Emissions testing plays an essential role in controlling vehicle pollution and conserving the environment. These evaluations confirm that vehicles comply with legal regulations for the release of harmful gases such as carbon dioxide and nitrogen oxides. Nonetheless, certain car producers have been discovered to be cheating in these evaluations.

The main motive for is monetary. Achieving emissions standards frequently necessitates costly technologies such as sophisticated catalytic converters or more environmentally friendly engine designs. For car manufacturers, these enhancements may reduce profits or increase vehicle prices for buyers, possibly leading to lower sales. By engaging in deceit, companies can evade these expenses while still seeming to adhere to regulations. Moreover, tougher emissions regulations in areas such as the European Union and the U.S. exert notable pressure on manufacturers to innovate quickly. When deadlines appear unattainable, certain automakers resort to shortcuts by altering test outcomes.

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Cheating also helps preserve a company’s reputation. For example, VW heavily marketed its "Clean Diesel" vehicles as Eco-friendly alternatives, but later investigations revealed the use of defeat devices—software designed to manipulate results during tests. These devices made cars appear cleaner while emitting up to 40 times the legal limit of pollutants in real-world driving. Toyota was recently fined for cheating, showing that even trusted industry leaders sometimes prioritize profits over compliance.

Other manufacturers have also faced accusations. Nissan falsified emissions data in Japan due to poorly managed testing systems. Opel was also found using defeat devices in Europe in 2015. And BMW was involved in an "emissions cartel" that sought to limit progress in AdBlue, a technology designed to decrease nitrogen oxide (NOx) emissions. Even Mercedes-Benz faced allegations of using defeat devices, though the company refutes the claims. John Stoll explains, “The emissions information says what the test needs it to say so that it passes regulatory tests. And then in real-world conditions, it emits far more of the harmful emissions such as NOx into the air than is legally allowed.”

While it’s unlikely that every car company cheats, the problem appears widespread enough to warrant concern. Weak enforcement and the potential for profit make cheating an attractive option for unethical companies. Nonetheless, many manufacturers do focus on compliance and put resources into cleaner technologies, demonstrating that innovation can occur without resorting to fraud.

To tackle emissions fraud, authorities need to enhance enforcement and apply stricter penalties. Third-party organizations should handle emissions tests to ensure impartiality, and carmakers should be incentivized to develop sustainable technologies. As consumers, we can help by choosing vehicles that have confirmed eco-friendly certifications, and insisting on increased transparency from carmakers.

CONTACTS

• Toyota Whacked with Gigantic Fine for Diesel Emissions Cheating, https://cleantechnica.com/2025/01/22/toyota-whacked-with-gigantic-fine-for-diesel-emissions-cheating/
• Volkswagen: The scandal explained,: https://www.bbc.com/news/business-44763905.

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