What Is The Difference Between The National Six Standards And The National Four And Five Standards

With the increasingly serious automobile exhaust pollution, automobile exhaust emission legislation is imperative. Countries around the world established corresponding laws and regulations on automobile exhaust emission as early as the 1960s and 1970s, which promoted the progress of automobile emission control technology through strict laws and regulations. With the continuous improvement of automobile emission control technology, it is possible to formulate higher standards of six standards.