Swedish professors: this is VW cheating – New Technology

       

Volkswagen cheating with emission values ​​of diesel cars in the United States have shocked the automotive industry. The carmaker has admitted that the software for the engine management has been manipulated so that the measurements provided better values ​​at the EPA’s tests than normal driving. The parameters they have tampered with is not known today. However, new technologies have talked with two vehicles professors about possible ways to cheat during an emission measurement.

– I think they may have lowered engine effect. This reduces both fuel consumption and emissions, says Magnus Skoglundh Chalmers Competence Centre for Catalysis.

In an emission test placed the car or truck on rolls in a test rig. Since running a driver vehicle according to a well-defined driving cycle. It simulates everything from a cold start to accelerations highway and starts and stops according to a set pattern. When the exhaust pipe is measured continuously the issues as there are statutory limits: nitrogen oxides (NOx), hydrocarbons, carbon monoxide and particulates.

Ingemar Denbratt, Professor of Combustion Engineering at Chalmers University, stresses that he does not know how Volkswagen has been cheated. But he believes that the car in any way have known that it is in the test rig and runs the certification cycle. Then, it may have changed its programmed parameters such as the time when diesel fuel is injected into the engine cylinder.

– If you postpone the injection time so drops nitrogen emissions significantly. At the same time pull the car when more fuel, and that one can not in actual driving, says Ingemar Denbratt.

Another possibility is that increase the exhaust gas recirculation. The so-called EGR amount, exhaust gas recirculation control how much exhaust gas back to the suction side to increase the mass in the cylinder and lower the temperature in the combustion. While it greatly reduces emissions of nitrogen oxides.

Both professors are very surprised by the revelation.

– It is amazing that such a large automakers dare to do so here. Absolutely unbelievable, says Magnus Skoglundh.

Ingemar Denbratt tells us that it is not the first time people are cheating at emission measurements. For about 20 years ago, an automaker put sensors on the hood that changed settings when you opened the door.

– So this is nothing new phenomenon. But they needed certainly much more sophisticated methods today, he said.

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