What is the difference between National 5 and National 6 emission standards?
2 Answers
The differences between National 5 and National 6 emission standards are: 1. Different emission levels: The carbon monoxide emission limit for National 5 is 1000mg per kilometer; for National 6 it is 700mg per kilometer. 2. Different restrictions: The sulfur content limit for National 5 is 10ppm, and the manganese content limit is 2mg per liter; for National 6, the sulfur content limit is 5ppm, and the manganese content limit is 1mg per liter. 3. Different forms: During the National 5 phase, diesel and gasoline vehicles had different emission standards; National 6 adopts a fuel-neutral principle, meaning the emission limits are the same regardless of the fuel type used.
The difference between the China V and China VI emission standards strikes me as quite significant. Technically speaking, China VI imposes stricter limits on pollutants. For instance, nitrogen oxide emissions under China VI are about 30% lower than under China V, and particulate matter is also significantly reduced. This is because China VI incorporates a real-time onboard diagnostic system that can detect exhaust abnormalities while driving. Additionally, engine designs have been modified, with more efficient fuel injection and catalytic converters, and the use of low-sulfur fuel is required to prevent system clogging. In the long run, China VI vehicles are more environmentally friendly, but the increased production costs may lead to slightly higher car prices. During maintenance, it's essential to regularly check the diagnostic interface; otherwise, it's easy for the malfunction indicator light to come on, affecting driving safety. I've also noticed that this standard has driven many automakers to innovate technologically, contributing significantly to improved air quality.
