In 2014, data by the until then little known non-profit International Council on Clean Transportation (ICCT ) showed that German car manufacturer Volkswagen was manipulating it's fuel emissions data on a grand scale. VW isn't alone in having sold cars with so-called defeat devices, a software that manipulates exhaust emissions on a test stand.
However, it's not just the emissions data that's misleading. Data compiled by the ICCT
also illustrates that there's a growing gap in how much fuel passenger cars actually consume under real world conditions and what manufacturers declare their car's intake is.