What do iv and v represent in terms of national emission standards?
3 Answers
National iv: IV is a Roman numeral, corresponding to the Arabic numeral 4, so National IV is the National 4 standard. National v: National 5 standard. National iv, National v, and National vi standards are all formulated to control vehicle exhaust emissions, including carbon monoxide, hydrocarbons, nitrogen oxides, solid suspended particles, etc. Below is relevant information about emission standards: 1. The National 4 standard was implemented nationwide on July 1, 2010. Compared to National 3, it upgraded the post-emission treatment system, reducing pollutant emissions by 50% to 60% compared to National 3. 2. The National 5 standard was implemented nationwide on January 1, 2018. Compared to National 4, it reduced nitrogen oxide emissions by 25% and added emission limits for non-methane hydrocarbons and PM, reducing atmospheric pollution and helping to prevent smog. 3. The National 6A standard was implemented nationwide on July 1, 2019. Compared to National 5, the National 6A standard tightened the CO limit for gasoline vehicles by 30%; the National 6B standard tightened CO and NOx limits by 50% and 42%, respectively. This means the National 6 standard is fully aligned with international standards.
IV represents the National Phase IV Emission Standard, abbreviated as China IV; V represents the National Phase V Emission Standard, abbreviated as China V. As a car owner, I find driving a China IV vehicle a bit of a headache during annual inspections because the exhaust emission tests are stricter, especially in large cities with frequent restricted zones. China V vehicles are much better, with lower pollutant limits and smoother driving. I remember a few years ago when I upgraded to a China V vehicle, the fuel consumption was slightly lower, and maintenance was less frequent. Emission standards actually affect the used car market value—China IV vehicles now depreciate much faster. Environmental awareness is also increasing, and the transition from China IV to China V represents the country's step-by-step efforts to reduce air pollution.
I'm discussing this from an automotive technology perspective: IV refers to China 4 emission standards, implemented in 2010, primarily targeting gasoline vehicle emissions with reduced limits for CO and NOx. V is China 5, fully rolled out in 2018, imposing stricter particulate matter restrictions for both diesel and gasoline vehicles, involving system upgrades like EGR valves and three-way catalytic converters. China 5 vehicles exhibit more responsive power delivery due to optimized engine tuning. Emission standard upgrades mean new vehicles must pass rigorous tests before hitting the road. With China 6 now becoming widespread, understanding the differences between China 4 and 5 is crucial for maintenance, such as regular OBD system checks to prevent emission issues.
