国家第四阶段机动车污染物排放标准
国家第四阶段机动车污染物排放标准-
但据中国环境保护部的数据，中国仅有5.7%的车辆符合最严格的国家第四阶段机动车污染物排放标准（国IV标准），该标准对包括温室气体和微小颗粒物PM2.5在内的废气排放做出了限制。
But according to China 's Ministry of Environmental Protection , only 5.7 % of China 's vehicles meet the country 's highest national Grade IV standards that limit toxic emissions from vehicles including greenhouse gas and tiny particulate matter known as PM2.5 .