How will the Volkswagen scandal affect diesel?

I must admit I’ve always been a little skeptical about this idea that diesel can be a “clean-burning fuel.” Anyone who has ever gotten stuck sitting behind a bus in traffic is likely to agree.

Thus it didn’t come as a complete surprise to find that Volkswagen has been cheating on its emissions testing over the last seven years. All that business about diesel burning clean AND offering better gas mileage seemed too good to be true.

Fortunately, Americans have never quite fallen for this line as much as Europeans. Diesels make up an incredible 53 percent of the automotive fleet in Europe, but it accounts for only 10 percent of all vehicles in this country. Europeans buy diesel mainly for gas mileage and are not too concerned about the pollution implications. A good diesel engine can get 36 miles to the gallon, while a gasoline engine usually tops out around 30, so there’s some logic to it all. Over the course of a year, that can save you upward of a thousand dollars.

But pollution standards are higher in this country, and that’s where VW ran into trouble. Back in 2005, the EPA was insisting that the company do something about NOx emissions, which are the major component of smog. In fact, the EPA banned the sale of diesels altogether in 2007 and 2008 because it couldn’t get any cooperation from the manufacturers in dealing with the problem.

At the time, the EPA was pushing a system called Selective Catalytic Reduction (SCL), in which a liquid such as urea is used to capture the NOx gases. The urea runs out regularly, however, and has to be refilled. U.S. regulators were pushing for a system that would disable the vehicle if it ran out of urea. Volkswagen didn’t want to inflict this on its customers and refused to go along. That’s when the total ban occurred.

Two years later, however, VW came back with what it said was a new system called Exhaust Gas Recirculation (EGR) that reduced the amount of oxygen available in the engine. Volkswagen engineers were even exuding that the air coming out of the 2009 Jetta was cleaner than the air going in. Green Car Journal was impressed enough to declare the Jetta its “Green Car of the Year.” (That honor, and the one VW earned for its 2010 Audi A3 TDI, have since been rescinded.)

Nitrous oxide and nitrous dioxide – the NOx pair – are not the product of gasoline combustion. Instead, they are formed when nitrogen and oxygen in the air encounter very high temperatures. This creates a conundrum. The higher the temperature of combustion, the cleaner the fuel is burning, which reduces carbon exhausts. But it increases to production of NOx gases. This is why it creates such problems for the manufacturers.

The EGR system may have reduced NOx pollution, but in fact what was really going on is that VW had installed “intelligent” software that was able to tell when the car was undergoing emissions testing rather than operating on the open road. The computer then changed the blend of fuel and temperature of combustion so that the NOx output was much lower. It was a diabolical plan, and more than a few people at VW must have known about it, but it succeeded over the next seven years. Emissions on the road during this time were up to 40 times higher than what was showing up in the laboratory.

Only last year did the International Council on Clean Transportation, a watchdog group that gets funding from both the industry and the government, start getting suspicious. They had long observed that VW diesels were emitting much more NOx gases on the road than was reported from the testing laboratories. They complained to both the EPA and the California Air Resources Board, which has even stricter standards. But it was another year before the EPA finally put the screws on VW and the company fessed up.

The revelation has put both the industry and the whole alternative-vehicle effort in a tailspin. Volkswagen will probably pay dearly for the deception. There are already studies claiming that the practice has caused $100 million in health damages. The figure seems exaggerated, but the company faces a raft of lawsuits. Some are questioning whether the world’s second-largest car company can survive.

“Selling large numbers of ‘Clean Diesels’ was central to VW’s scheme for cracking the American market, a weak spot, which in turn was a vital part of the plant to overtake Toyota as the world’s largest carmaker,” writes The Economist. “That grand strategy … now lies in ruins.”

The other question is whether diesel can survive as a technology. “If Europe stages a wholesale shift away from diesel, manufacturers could be forced to make a bigger than anticipated push into electric vehicles in order to comply with the EU’s 2020 targets on carbon dioxide emissions,” writes the Financial Times. Some are not disappointed. They see Europe’s diversion into diesel as a way of avoiding the much more difficult choices in reducing carbon emissions. Backers of ethanol and methanol are making their pitch.

As one commenter writes in MIT Technology Review: “VW just killed the passenger car diesel engine. VW has stopped selling all diesels in the US and Germany  putting a pox on other manufacturers [as well]. Cadillac was allegedly coming out with a diesel in 2016, but VW has sent that to the land of unicorns. Now the only road to redemption … lies exclusively in hybrids and EVs.”

Diesel will probably survive, but its role as an alternative fuel for small passenger cars is likely to be significantly diminished.

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