When the International Council on Clean Transportation began to look into discrepancies in the emissions of several of Volkswagens diesel vehicles in early 2014, it was with the sincerest of intentions. Noting that the U.S. had stricter and more rigorously enforced emissions laws that Volkswagen’s TDI-equipped cars routinely passed without problems, the ICCT figured performing some test on U.S. soil would provide them with a good control model, and maybe illuminate the some of the reasons why diesel Volkswagen’s cars sold in the states seemed to perform so well. Enlisting the help of the West Virginia University’s Center for Alternative Fuels, Engines, and Emissions (CAFEE) to assist with the real-world testing, it seemed the data would soon reveal the root of the inconsistencies. But when the results gathered via real-world testing were compared with the compliant numbers generated in the lab by the California Air Resources Board (CARB), it was clear something wasn’t kosher in dieselburg.
-To shed some additional light on the situation, C/D spoke with Daniel Carder, Interim Director of the Center for Alternative Fuels, Engines, and Emissions, and Dr. Arvind Thiruvengadam, Research Assistant Professor. Both were participants in the testing sessions where the discrepancies were first discovered, and replied candidly.
-Armed with several of its Portable Emissions Measurement Systems (PEMS), CAFEE hit the road in a number of VW diesels—as well as a diesel BMW X5, according to a report in Bloomberg—to compile some real-world road-test emission numbers for comparison with the CARB numbers, which fell fully within the accepted levels of NOx emissions. Before long, it was obvious that something was terribly wrong: The Jetta exceeded the U.S. nitrogen oxide emissions standard by 15 to 35 times, and the Passat by 5 to 20 times. The X5 passed.
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According to Dr. Thiruvengadam, when the teams began comparing data, their first response was, “That’s not right,” and immediately started accusing each other of forgetting a crucial procedure or step that could have corrupted the data. Only after double- and triple-checking their work for accuracy did they begin to look to the vehicles for an explanation. “We were amazed,” he says. “The engine software had to be responsible.”
-“Developing an engine software to optimize certain aspects of an operation cycle that you know the parameters of is a challenge, but it is very possible,” says Thiruvengadam. “Knowing when to switch to the EPA-favorable cycle is the trick; it could be set up to detect the absence of steering wheel movement, or, and this is known, we often turn off the traction control for testing purposes.” Either way, the result is the same: it turns the emissions controls on for EPA testing, and off for real-world driving. Somewhat-ironically, the presumed benefits of turning off the controls for normal driving include improved fuel economy and engine power.
-Both Thiruvengadam and Carder state that, to their knowledge, no external devices were employed, and the so-called “defeat-device” was entirely software related. Thiruvengadam called the software “very-sophisticated in design and operation,” and said it would be “highly unlikely that even the most perceptive drivers would ever be able to sense it activating or deactivating.”
-Armed with this info, CARB and the U.S. Environment Protection Agency opened an investigation into Volkswagen in May 2014, which resulted in many attempts by VW to replicate the West Virginia University results. In December of 2014, VW said it had a fix, and recalled nearly 500,000 diesels in the U.S for a software patch. But while VW held its breath, CARB continued to test Volkswagen diesels on a regular basis, and found that the cars were still exceeding the state’s nitrous-oxide emission limits. CARB made its finding known to both Volkswagen and the EPA on July 8th.
-Only when Volkswagen learned that the certification of some of its 2016 model-year cars was partially dependent on the maker fully responding to lingering questions over the cars’ real-world tailpipe emissions did the maker begin to respond in earnest. After weeks of receiving unsatisfactory replies, the agencies in question let VW know several of its diesel models would not be certified for 2016. Volkswagen did not respond to C/D inquiries for comment.
-With the prospect of not being allowed to sell diesels in the U.S. (current estimates indicated diesels make up about 25 percent of Volkswagen’s U.S sales) the maker finally retreated, and admitted it had knowingly installed a “sophisticated software algorithm” that permitted the diesels to reduce the amount NOx emissions while undergoing testing.
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- VW Issues Stop-Sale Order for All 2.0-liter TDI Diesel Models
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- Long-Term Test: 2013 Volkswagen Passat TDI SEL Diesel
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- Volkswagen Allegedly Openly Violated EPA Diesel Laws, Could Face Billions in Fines
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When asked if they thought other carmakers might be engaging in the same deceptive practices for the purpose of passing stringent emissions testing or to inflate fuel-economy numbers, Carder and Dr. Thiruvengadam chuckled simultaneously and replied, “maybe, but it’s not fair to speculate at this point. But I hope not,” says Carder, “as science nerds like us don’t usually get this many phone calls.”
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from Car and Driver Blog http://ift.tt/1LJ3607
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