It seems the diesel motor will finally get its comeuppance now. Due to a court ruling, Stuttgart may have to impose a driving ban for older diesel cars as early as next year.

The southern German city lies in a valley basin that makes it prone to inversion weather conditions, meaning it frequently suffers from smog and huge quantities of respirable dust in the air. It is also the seat of the oldest carmaker in the world, Daimler, whose founder once claimed to have invented the automobile and whose successors at the company made the diesel motor an effective piece of car engine technology.

Each day, thousands of workers commute to Stuttgart by car - and most of them drive diesels because the fuel is subsidized by the German state, making them more cost-efficient.

Ironically, it may now be Stuttgart that is going to ring the death knell for the diesel car in German cities. On Thursday, the Transport Ministry in Berlin imposed a sales ban on 3-liter diesel SUVs manufactured by sports car maker Porsche , another carmaking giant based in Stuttgart. Porsche was caught cheating on diesel emissions tests with a so-called defeat device - software that manipulates the car's emissions control system.

Watch video 01:33 Share Looming diesel ban worries German taxi firms Send Facebook google+ Whatsapp Tumblr linkedin stumble Digg reddit Newsvine Permalink https://p.dw.com/p/2hKe1 Looming diesel ban worries German taxi firms

Pars pro Toto

Meanwhile, the ruling by the court in Stuttgart on Friday has been closely watched by city councilors across Germany, who face similar problems with high air pollution and clean air acts that are woefully insufficient to curb rising emissions from traffic. But does this mean they have now been given a free hand to impose wholesale bans on diesel cars? Not quite.

DW business editor Henrik Böhme

First, there is still a ruling pending in Germany's highest administrative court as to whether municipalities are actually allowed to impose such bans. Second, the Stuttgart ruling was made by only a first-instance court, so those opposing it will surely appeal this and other likely rulings against them all the way up to the highest German court. Most importantly, Germany's mighty carmakers will certainly move to act now, as they are unlikely to simply let go of a technology that has reaped them huge profits for decades.

Test of German engineering prowess

Under fierce fire for emissions cheating and antitrust behavior, the beleaguered German auto industry now has to deliver on its promise of riding on the cutting edge of technology. And the court in Stuttgart has made sufficiently clear that a simple software update won't do.

What is required now is state-of-the-art particle filters and whatever else is available in terms of modern technology to come to grips with hazardous diesel emissions. Engineers at Daimler, Volkswagen and other German automakers are now called upon to bring out their best, no matter if it costs lots of money. After all, they have earned plenty in recent years.

On August 2, they will have the opportunity to take the first step in regaining lost trust. At a meeting between government officials and representatives of the German auto industry - already dubbed a diesel summit - proposals need to be put on the table about how they want to curb hazardous nitrogen oxide in diesel exhausts.

Should the car bosses botch this opportunity, they will be completely at sea. What else, then, would it take for them to wake up other than hitting a wall with open eyes? Don't they realize that a driving ban for diesels in inner cities is just the first step towards measures that will hurt even more?

And how about all the other carmakers? Not all of those living in Stuttgart drive Mercedes and Porsches. The majority certainly own Peugeots, Toyotas or Volvos - cars that are not exactly known for a higher degree of environmental friendliness. None of them has ever come forward, saying they too want to step up to the challenge.

Dieselgate: A timeline The disaster unfolds — September 2015 About two weeks after Volkswagen admitted behind closed doors to US environmental regulators that it had installed cheating software in some 11 million of its diesel vehicles worldwide, the Environmental Protection Agency shared that information with the public. It was September 18, 2015. The ensuing crisis would eventually take a few unexpected turns.

Dieselgate: A timeline The boss must go, long live the boss — September 2015 Volkswagen's then-CEO Martin Winterkorn (above) had little choice but to step down several days after news of the scandal broke. In September 2015, he tendered his resignation, but retained his other posts within the Volkswagen Group. Winterkorn's successor was Matthias Müller. Until taking the reins at VW, Müller had been the chairman at Porsche, a VW subsidiary.

Dieselgate: A timeline Raiding headquarters — October 2015 Regulators in the US weren't the only ones investigating VW. Authorities in Lower Saxony, the German state in which VW is based, were also scrutinizing the company. On October 8 2015, state prosecutors raided VW's headquarters along with several other corporate locations.

Dieselgate: A timeline Hell breaks loose — January 2016 On January 4, 2016, the US government filed a lawsuit against VW in Detroit, accusing the German automaker of fraud and violations of American climate protection regulations. The lawsuit sought up to $46 billion for violations of the Clean Air Act.

Dieselgate: A timeline Quit or forced out? — March 2016 In March 2016, the head of VW in the US, Michael Horn, resigned. In the initial days and weeks after the scandal broke, he was the one US authorities turned to for information. He issued an official apology on behalf of the automaker, asking for the public's forgiveness.

Dieselgate: A timeline Settlement — October 2016 On October 25 2016, a US judge approved a final settlement that would have VW pay $15.3 billion. In addition, affected cars would be retrofitted with better, non-deceptive hardware and software, or else VW would buy them back completely from customers.

Dieselgate: A timeline Imitators — July 2017 When dieselgate first emerged in 2015, analysts said it was likely other car makers were also cheating tests. But it wasn't until 2017 that other companies were targeted in probes. In July, German authorities launched investigations into luxury car makers Porsche and Daimler for allegedly cheating emissions tests. Others, such as Audi and Chrysler, have also been hit by similar allegations.

Dieselgate: A timeline Public still supportive — December 2017 Despite dieselgate, VW has managed to keep the emissions scandal from utterly tarnishing its image. According to several polls, between 55 to 67 percent of Germans continue to trust the automaker. In the US, polls show that roughly 50 percent still believe the German company produces worthwhile vehicles.

Dieselgate: A timeline Fuming over monkeys — January 2018 In late January, however, VW suffered another heavy blow over reports that the company experimented on monkeys and made the animals inhale diesel fumes. To make matters worse, a separate experiment that had humans inhale relatively harmless nitrogen dioxide was revealed at the same time. Some media wrongly interpreted this to mean humans were also inhaling toxic fumes.

Dieselgate: A timeline Canadian court demands millions — January 2020 Years after the scandal that caused Volkswagen to pay CAN$2.4 billion (US$1.83 billion), a court in Toronto order a further fine of CAN$196.5 million. Volkswagen pleaded guilty of violating in environmental laws. Prosecutor Tom Lemon noted that the fine was "26 times the highest fine ever for a Canadian environmental offence." Author: Dirk Kaufmann, Elliot Douglas



National soul-searching

But what the German debate about diesel emissions and the future of the car industry requires first and foremost is less ideological vociferation.

Take Stuttgart itself for an example: Much of the respirable dust pollution in the city doesn't originate from traffic at all. It is the result of a mixture of adverse weather conditions, location and other causes like surrounding agriculture.

Matthias Klinger, a renowned transportation research expert, argues that even a complete ban of traffic in the city would reduce dust pollution only by about 10 percent.

Another example is Hamburg. The northern German port city, too, would benefit from a driving ban only marginally because the huge container and cruise ships in its harbor spew out tons more dangerous emissions. Will they have to remain moored outside of the city in the future?

No, it is definitely too early to call it the end of the diesel engine. But the ruling in Stuttgart is a signal that needs to be heeded by politicians as well as the auto industry. It has finally unleashed a serious debate about the health hazards of car emissions and how to curb them. More than that: Germans are starting to rethink their individual mobility and what role the country's mighty auto industry has to play in it.

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