What does China III and China IV mean for vehicles?
2 Answers
China III and China IV refer to the vehicle emission standards, with China IV being more stringent than China III. The China III emission standard, officially known as the National Phase III Motor Vehicle Pollutant Emission Standard, was implemented nationwide on July 1, 2007. It is equivalent to the Euro III emission standard in terms of tailpipe pollutant levels, with the key difference being that new vehicles must be equipped with an OBD (On-Board Diagnostics) system. The China IV emission standard, officially the National Phase IV Motor Vehicle Pollutant Emission Standard, mandates that only China IV-compliant vehicles can be registered starting from July 2011. The OBD system under China IV features increased monitoring points and systems, including oxygen sensors at both the inlet and outlet of the three-way catalytic converter, to ensure real-time monitoring and compliance with emission standards.
National III and National IV are topics I often discuss in car enthusiast groups. Simply put, they are China's vehicle emission standard codes, with National III representing the third stage and National IV the fourth stage. National III was implemented around 2007, requiring new vehicles to reduce pollutants like hydrocarbons and carbon monoxide in exhaust emissions, basically equivalent to Euro III internationally. National IV is stricter, introduced around 2011, imposing much lower limits on nitrogen oxides and particulate matter, comparable to Euro IV. Why implement them in stages? Because pollution control is a gradual process; in the early years, vehicle exhaust made cities hazy, but after the upgrades to National III and IV, air quality has indeed improved significantly. An old comrade of mine who drives a taxi complained that switching to a National IV vehicle was more expensive, but it's worth it in the long run because National III vehicles are now banned from entering the ring roads in big cities. So understanding these standards is crucial for us when choosing and using cars—don't buy vehicles that are too old to avoid problems.
