为分析在用汽油车排放污染物超标的原因，统计分析北京市14,954条在用汽油车ASM工况排放检测数据分析，研究不同排放阶段车辆不同基准质量超标情况和不同污染物的超标类型及原因。结果表明：国三、国四轻型汽油车随着基准质量的增加，超标率降低，呈负相关关系；轻型汽油车NOx超标导致排放不合格的比例最高，HC超标的比例最低，CO超标的比例介于两者之间，重型汽油车以NOx超标为主。
In order to analyze the reasons for the excessive emissions of the different emissions, the exceeding standards rate of different emission stages vehicles with different reference mass from in-use gasoline vehicles, the emission test data of 14,954 in-use gasoline vehicles under ASM conditions in Beijing were analyzed. The results show that with the increase of the reference mass, the exceeding standard rate of light-duty gasoline vehicles in stage 3 and stage 4 decreases, showing a negative correlation; light-duty gasoline vehicles have the highest proportion of unqualified emissions caused by excessive NOx, the lowest proportion of HC exceeding the standard; heavy-duty gasoline vehicles are dominated by excessive NOx.
