the emission standard in US and EU have different focus. benefit

 US is more concerned health impact, EU is more for fuel efficiency. TDI tech. helped diesel car market, benefited German cars. I heard (I am not sure it is true) aimed keep diesel car out of US market, US intentionly set two standards for diesel car and truck with large discrepancy to make diesel car can hardly pass it while keep the performance as maker claimed. VW played dirty to deal with this standard.