Abstract:

This study highlights the widespread prevalence of calibration strategies in Euro 5 and Euro 6 diesel cars leading to excess NOx emissions and the comparatively limited corrective action to date. With a clarified definition of defeat devices and the rules prohibiting their use from recent CJEU rulings, EU Member State and UK market surveillance authorities now have a clear basis on which to address excess NOx from prohibited defeat devices and implement systemic changes in testing and enforcement practices.