When Diesel Was The Future of Clean Cars
In the early 2000s, the world was beginning to worry more than ever about climate change. However, since electric cars were still slow, expensive, and niche, automakers and governments needed a quick fix, and Diesel engines looked like the solution. They promised lower CO₂ emissions and better mileage. The best thing about it is, it already existed. When governments found out about these advantages, some offered tax breaks for diesel cars. Automakers even marketed them as eco-friendly, which made consumers believe that buying a diesel meant they were helping the planet.
For a while, diesel looked like a great environmental and engineering choice. Diesel engines are up to 15%-20% more efficient than gasoline ones, meaning they burn less fuel per mile, which also means less CO₂, the point of all the climate policy at the time.
With all of the government support and environmental numbers, Diesel took over everywhere. Europe became the diesel capital of the world with companies like VW and Mercedes pushing entire diesel lineups. By 2010, about half of all new cars sold in Europe used diesel in their engines. automakers would brag about their clean diesel technology, with particular parts like filters and catalytic converters that were supposed to fix the pollution problem.
But there was actually a huge trade-off that few consumers understood about. While diesel does lower CO₂ levels, it produces a lot more nitrogen oxides and soot. These chemicals harm the lungs and create smog. To meet stricter air standards, automakers added complex exhaust systems, but they didn't always work well in real-world driving. Filters usually clogged easily or just failed. Some systems would actually reduce NOx, but only during lab tests and not on he road.
All of this led the the dieselgate scandal of 2015. The U.S. Environmental Protection Agency (EPA) discovered that Volkswagen had actually installed “defeat devices,” which were software that recognized when a car was being tested and would make it reduce its emissions temporarily. Volswagen diesel vehicles actually emitted up to 40 times the legal NOx limit! This scandal spread fast, with other companies like Audi, Mercedes, Fiat, and Renault facing similar investigations. VW marketed the same cars as “Clean Diesel” vehicles; they even released this ad:
All of this led to Volkswagen’s CEO resigning, and the company having to pay $30 billion in fines and settlements!
After Dieselgate, we saw immediate effects across the industry. Public trust was lost, governments began discouraging owning a diesel vehicle, and car resale values of diesels dropped considerably! Cities like Paris, London, and Madrid actually started banning older diesel cars, and the share of Diesel in the European market fell from about 55% in 2011 to under 20% by 2023. All of this made VW and others pivot toward electric vehicles to rebuild trust and credibility.
There are also modern consequences. Even if Dieselgate didn’t happen, diesel still would become more costly. But it did affect other areas, like creating high maintenance costs due to filters in AdBlue tanks and sensors. Also, many governments raised diesel taxes to match or exceed petrol taxes. The 2022 oil supply disruption for Russia and Ukraine didn't help and raised diesel fuel prices sharply. So all this means even if all the drama didn’t happen, the cost would have still spiked.
Diesel started the bridge to a greener future, but ended as the cautionary tale of quick fixes and corporate shortcuts. It helped carmakers meet CO₂ goals but ignored local pollution. Its downfall made way for other types of energy like electricity. Today, diesel is only in trucks, heavy-duty vehicles, and very few cars.
If you were an engineer or policymaker back then, would you have made the same bet on diesel? Do you think Volkswagen ever truly recovered from Dieselgate, or did it make consumers wary of buying from it? Do you own or want to own a diesel car? Do you think diesel will make a comeback as cleaner versions appear, or is its time completely over? Let us know in the comments!
Source:BBC Images:ForceGT,Diesel Army,and