The “Dirty Thirty” span across most carmakers with Renault (four), Mercedes (three) and Opel/Vauxhall (three) standing out. Each car was approved by one of seven national type approval authorities. Nine cars were approved in the UK; Germany and France each approved seven; the Netherlands approved three; Luxembourg two; and Spain and Italy one each.
The regulators have to date taken no legal action against any of the carmakers or taken forward more in-depth investigations to scrutinise whether the models used illegal defeat devices despite strong evidence that they did, including: inappropriate use of a ‘thermal window’ (29 models); high ‘hot restart’ emissions (23 models) and plain shut-offs after a certain time (at least one model). Urgent action is needed by national agencies (TAAs) to investigate these suspect emissions control strategies.