Environmentalists have established short-term and long-term standards in the hope that makers can improve engine R & D, eliminate old models and bring out new ones that make less polluting.
環保署因此有所謂一期、二期排放標準，目的希望廠商能加強對引擎的研發，逐步淘汰舊車、推出汙染量少的新車。