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.

在汽的一个测试循环中,约污染物总量70%～80%的非甲碳氢化合物是在汽起动阶段没有经催化转化而直接入大气中,造成严重污染。