China, home to 170 million vehicles, will adopt one of the world's strictest standards on vehicle exhaust emissions to further control air pollution, starting in two phases in 2020 and 2023. All light vehicles should follow the new China's National IV standard A starting from July 1, 2020, and then should follow the even stricter standard B starting from July 1, 2023. According to the Ministry of Environmental Protection, 86.9 per cent of carbon monoxide and 92.2 per cent of nitrogen oxides stem from vehicles exhaust. In addition, the ministry said with technical support the petroleum plants will be ready to provide high quality petroleum for most vehicles by 2020. To the article..