VW had a desire to overtake Toyota in the American market. VX had just 2 per cent of the US car sales, a fraction of what Nissan and Toyota have. It is less than that of American car companies Ford or GM. Toyota’s hybrid car Toyota Prius met the emission norms. Diesel as a fuel was associated with smoke-belching buses and roaring 18-wheelers, and this perception of it being a dirty fuel was difficult to remove. Diesel could give more mileage per gallon and it was for the car companies to establish it as a clean fuel. Heavy vehicles carry a tank of urea-based solution which reacts with nitrogen oxides ( NOx ) emission of diesel, and bind them. This reduces pollution, but the extra tank increases the weight, and reduces the performance. VW claimed that even without this extra tank, their diesel was a clean fuel; with fuel efficiency of hybrids. The strategy made VW to go past Toyota in terms of sales. Here was a car that was environment friendly without sacrificing performance.

However, West Virginia university researchers were perplexed by fuel emissions in the lab and on the road of the so-called clean cars. They observed these discrepancies in 2013, and the findings were reported in 2014. The brands were not mentioned. This prompted California regulators to conduct their own investigation. This led to the discovery of a software installed by VW to cheat on emission norms. It was installed on 11 million diesel cars worldwide. It was activated in lab conditions so that the car passes the test. Once the cars were out of the laboratory, it was deactivated, and the cars emitted fumes 40 times the permitted levels.

The event will affect the car makers, other countries and the future of diesel itself.