The Dieselgate scandal, emerging in 2015, initially started after it was uncovered that a number of Volkswagen vehicles had cheated on emissions tests by using specialised technology to disguise the actual levels of pollutants they were emitting when on the road.
This was uncovered in the US by the Environmental Protection Agency (EPA), who found that many diesel engine VW vehicles had a “defeat device” – this being software that could detect when it was being tested and alter its performance accordingly to yield better, fake, results.
The software was able to sense test-like scenarios through speed, air pressure, engine operation and steering wheel position, and would subsequently shift the vehicle into something of a safety mode, making the engine run below full power. This resulted in engines omitting up to 40 times more nitrogen oxide pollutants than the US’s regulatory limit.