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环中,约占排放污染物总量70%～80%的非甲合物是在汽油机冷起动阶段没有经催转而直接排入大气中,造成严重污染。