Because of testing inefficiencies, maintenance inadequacies and other factors, diesel cars, trucks and buses worldwide emit 4.6 million tons more harmful nitrogen oxide (NOx) than standards allow, according to a new study co-authored by °ÄÃÅ¿ª½±½á¹û2023¿ª½±¼Ç¼ researchers. The study, published today in Nature , shows these excess emissions...