In a testing of petrolic engine, about 70% to 80% of nonmethane hydrocarbon is emitted into atmosphere without catalysis conversion in theoment of coldstart, so that serious pollution is produced.

在汽油机的一个测试循,占排放污染物总量70%～80%的非甲碳氢化合物是在汽油机冷段没有经催化转化而直接排入大气,造成严重污染。