By cheating emissions regulations with software tricks, Volkswagen AG has put a stake into the heart of diesel-powered passenger cars.

Moreover, the unfolding scope of the VW scandal now threatens the very future of what was once the world’s largest and one of its most respected car companies – and we are not even taking into consideration the most recent news about whatever games VW may or may not have been playing with fuel economy numbers.

But in truth, diesel’s grave was being dug years ago. Long before VW was caught cheating, the everyday diesel runabout was coughing and wheezing in the marketplace. Thanks to VW, however, diesels now are zombies – the rolling dead.

The zombie metaphor is apt. You see, we still don’t know the extent of this diesel mess. We do know that the U.S. Environmental Protection Agency (EPA) alleges that “VW developed and installed a defeat device in certain VW, Audi, and Porsche light duty diesel vehicles equipped with 3.0 liter engines for model years (MY) 2014 through 2016 that increases emissions of nitrogen oxide…up to nine times the EPA’s standard.”

Vehicles implicated include diesel versions of the 2014 VW Touareg, the 2015 Porsche Cayenne, and the 2016 Audi A6 Quattro, A7 Quattro, A8, A8L, and Q5. In response, VW told U.S. and Canadian dealers to stop selling recent models equipped with its 3.0 V6 TDI diesel engine.

Nonetheless, VW reacted this way to the EPA: “Volkswagen AG wishes to emphasize that no software has been installed in the 3-liter V6 diesel power units to alter emissions characteristics in a forbidden manner,” adding that “Volkswagen will cooperate fully with the EPA clarify this matter in its entirety.”

Cynthia Giles, Assistant Administrator for the Office for EPA’s Enforcement and Compliance Assurance, also suggested that the agency will keep digging into this problem right across the industry.

“All companies should be playing by the same rules. EPA, with our state, and federal partners, will continue to investigate these serious matters, to secure the benefits of the Clean Air Act, ensure a level playing field for responsible businesses, and to ensure consumers get the environmental performance they expect.”

Will other car companies be bitten by a future diesel scandal? Who else might have been flouting emissions rules in ways similar to VW? If you’re a car shopper, why would you risk buying a diesel?

At a time of growing public consciousness about “green” issues, we know that thanks to VW’s cheating, millions and millions of dirty diesels have been pumping massive amounts of pollutants into the air we breathe. You are right to be appalled.

Even if you’re not, consider the ugly economic case around buying a diesel. The resale value of the millions and millions of VW Group vehicles we know about has been torched. Who would buy a new diesel knowing it could worthless in a few years?
In answer, diesel fans and apologists make two key points:

First, as a general rule, larger diesel-powered vehicles are not a problem. They use engines that reduce emissions thanks to a urea solution called AdBlue. These rigs are as clean as any passenger vehicle with a gas motor.

The lobby group Diesel Technology Forum argues that the new generation of clean diesels achieves near-zero emissions of oxides of nitrogen and particulate matter. Advanced engine technologies, new emissions control systems, particulate filters and selective catalytic reduction systems have driven down diesel emissions to gasoline car-like levels.

Second, diesels in many markets, particularly in Europe, are entrenched and have been very popular. Take France. There, diesel cars accounted for 64 percent of vehicle registrations in France as of the end of 2013, according to the French Car Manufacturers (CCFA); about half the cars on French roads are diesels.

France, though, is falling out of love with diesel, just like the rest of this world. Early in 2015, Le Conseil de Paris – the Paris city council – adopted an energy transition law designed to rid Paris completely of diesels. By 2017-2020, diesel cars made prior to 2011 will be prohibited.

More broadly, France’s 2015 environmental road map seems intent on phasing out diesels altogether by 2020. Officials in France and all around the world are pursuing regulations in favour of electric vehicles and gasoline-electric hybrids.

With good reason. Most politicians lead by following opinion polls. It’s clear that public opinion started to turn against diesel in Europe well before VW’s horrific behaviour. But now we know diesel’s certain fate. Max Warburton of Bernstein Research is among the very well informed analysts and experts who believe the VW affair marks the end of diesel, reports Reuters.

Of course it is possible to build relatively clean diesel passenger vehicles, but the price to make them compliant with ever-stricter emissions regulations makes them increasingly uneconomical. Cheap and abundant gasoline for cars that are less expensive and cleaner than most diesels has already started to hammer diesel demand. Diesels are also being hit by the increasing popularity and affordability of hybrids and EVs which are coming to market in ever-increasing numbers.

But it is diesel’s soiled reputation that is most important in a car industry that relies on emotion to move the hardware. VW’s lies and deceptions have created a diseased image for diesels: they are sick and if you drive a diesel, many now feel you’re sick by association.

That harsh reality is terminal for diesel.