What are the differences between National III and National IV vehicles?
2 Answers
The differences between National III and National IV vehicles: 1. Different markings: National III vehicles are marked as 'National III'; National IV vehicles are marked as 'National IV'. 2. Different numbers of processing systems: National III vehicles have one muffler; National IV vehicles have two mufflers. 3. Different traffic restrictions: National III vehicles can enter within the Sixth Ring Road; National IV vehicles are not subject to any restrictions. 4. Different engines: National III vehicles use direct injection in the cylinder with a large pump fuel supply method; National IV vehicles use electronic injection in the cylinder with a common rail fuel supply method. National III vehicles comply with China's third-stage vehicle emission standards. National IV vehicles comply with China's fourth-stage vehicle emission standards.
I work in auto repair, and the main difference between China III and China IV vehicles lies in the exhaust system. China IV vehicles have an additional automatic diagnostic system called OBD, which triggers a fault light when emissions exceed standards, and the exhaust pipe also includes an adsorption device. The most obvious difference is the manufacturing year gap—most vehicles produced between 2007 and 2011 are China III, while those after 2011 are mostly China IV. After installing a urea system, China IV vehicles can reduce fuel consumption by about 5%, but maintenance costs are significantly higher—replacing a catalytic converter can cost three to four thousand yuan. During inspections, many China III vehicles barely pass the emissions test, as the allowable limits are nearly double those for China IV. Many cities now restrict China III diesel vehicles from entering urban areas, so if you're hauling goods, I recommend buying a used China IV vehicle directly.
