5.4 Cheating on emission standards

So far, all of the emissions performance data given has been under ‘standard driving cycle’ conditions. This raises the interesting possibility that a car’s computerised engine management system might be able to recognise when the car was being ‘tested’. It could then comply with the NO_x emission regulations by limiting the peak power but ignore them otherwise.

In late 2015 the head of Volkswagen’s US business admitted to a US court that some of their cars had such a system. In 2017 the company agreed to pay US$4.3 billion in civil and criminal damages in the US. The company admitted that its specialists were not able to reconcile the conflicting goals of fuel economy and emissions, given the competition from hybrid petrol-electric cars (described later). Worldwide Volkswagen were forced to buy back hundreds of thousands of vehicles. By the end of 2018, the cost to the company was US$21 billion.

In 2016 the humorous scientific magazine Annals of Improbable Research awarded the ‘Ig Nobel Prize’ in chemistry to Volkswagen for this elegant method of ‘solving the problem of excessive automobile pollution emissions’.

The effect on the ‘green credentials’ of diesel cars has been considerable with calls for them to be banned from many European cities. The scandal has seriously assisted the move from fossil fuelled to electric cars.