The world’s largest (interim) automaker, Germany’s Volkswagen Group, has been caught cheating on emissions regulation testing in the United States when it comes to diesel-powered cars.
The company was confronted with the findings and admitted to the violation of emissions tests in its diesel-engined models, while the US regulators have already announced widespread investigations that would also target other carmakers. We have decided to explain a bit how VW’s “defeat device” software worked around federal regulation tests as it cheated the standards imposed by the U.S. Environmental Protection Agency (EPA) and the state of California.
Diesel engines are one of the most spread alternative to gasoline engines and don’t have spark plugs or distributors, the fuel used is less refined and delivers higher energy density than gasoline, making the engine itself more efficient – its price today is higher than its counterpart, taking away one of the selling point of diesel vehicles. They do tend to have around 30 percent better fuel economy than a comparable gas powered car and can beat even the gasoline-electric hybrids.
When it comes to emissions, as the fuel is heavier and oilier and less refined it will be more polluting – mainly when it comes to nitrogen compounds. The diesel fuel will deliver less carbon monoxide, hydrocarbons and carbon dioxide than a similar gasoline engine. Thus, the biggest problem for the manufacturers is the nitrogen oxide, or NOX emissions, requiring the use of pollution control systems in order to fall into the standards set by the US or the European Union.
VW’s “defeat device” is software that detected precisely the conditions used when the federal emissions testing is done, switching on the pollution prevention systems under those circumstances and cutting it off during normal operation.