https://phys.org/news/2018-05-germany-porsche-recall-diesel-emissions.html > "Defeat devices" refers to software designed to reduce harmful emissions under regulatory test conditions compared with real on-road driving. > A Porsche spokesman said across Europe, some 53,000 Macans fitted with 3.0 litre diesel engines and 6,800 4.2-litre Cayennes were affected by the recall.