What are the differences between National IV and National V standards?

[BethanyRose]

National IV and National V standards differ in the following aspects: 1. Different emission standards: Compared to National IV, National V has stricter emission standards, resulting in fewer pollutants emitted and being more environmentally friendly. 2. Different control systems: National V mainly features more complex emission control systems compared to National IV, leading to increased costs. 3. Different pollution levels: To further reduce photochemical pollution caused by gasoline evaporation emissions and decrease deposits in car engine intake systems, the olefin content has been reduced from 28% in the fourth stage to 24%. 4. Different evaporation properties: The saturated vapor pressure of National IV gasoline ranges from 42 to 85, while that of National V gasoline ranges from 45 to 85.