What is the difference between National IV and National V vehicle emission standards?

[DerekMarie]

Here are the specific differences between National IV and National V standards: 1. Sulfur content: The sulfur content limit for National IV standard gasoline is 10mg; while for National V standard gasoline it's 50mg. 2. Emission limits: National V has stricter control on nitrogen oxides compared to National IV, with National V setting the emission limit at 25%. The National IV emission standard is China's fourth-phase motor vehicle pollutant emission standard, with main vehicle pollutants being HC, NOx, CO, PM, etc. Compared to National IV, the National V standard can reduce nitrogen oxide emissions by 25% for light-duty vehicles and 43% for heavy-duty vehicles.

[McColin]

The differences between China IV and China V standards are indeed significant, with the most crucial aspect being the varying emission requirements. The China V standard imposes much stricter limits on pollutants like carbon monoxide and hydrocarbons compared to China IV – for instance, the maximum allowable hydrocarbon emissions under China V are approximately half those of China IV. In terms of implementation timeline, China IV was rolled out nationwide in 2010, while China V was fully enforced in 2017. Technologically speaking, China V-compliant vehicles are generally equipped with more efficient three-way catalytic converters and higher-precision oxygen sensors. For regular car owners, China V vehicles are more environmentally friendly and have an easier time passing annual emission tests, but they require gasoline that meets the China V standard; otherwise, the malfunction indicator light may activate. When purchasing used cars nowadays, special attention is needed as China IV vehicles face driving and transfer restrictions in many cities, leading to faster depreciation.

[VivianLynn]

I've specifically researched this difference. China 5 is stricter than China 4, mainly reflected in pollutant control values. For example, the nitrogen oxide limit decreased from 0.08 grams per kilometer under China 4 to 0.06 grams. There are also design changes - China 5 vehicles have higher sealing requirements for fuel systems to prevent oil vapor leakage pollution. After 2017, most new cars sold were at least China 5 compliant, with some regions even mandating China 5 for registration. In the used car market, it's common for China 5 vehicles from the same year to cost several thousand yuan more than China 4 models. They're more worry-free to use without concerns about changing traffic restriction policies. Looking long-term, with China 6 already implemented, China 4 vehicles will undoubtedly face increasing usage restrictions.

[AmirRose]

The most significant difference lies in pollution control. China 5 imposes stricter limits on harmful substances in exhaust emissions. For example, particulate matter emission requirements are 80% more stringent than China 4. The technological upgrade is reflected in more precise engine electronic control systems and higher combustion efficiency. The practical difference for vehicle usage is that China 5 requires higher-quality gasoline; otherwise, sensors are prone to false fault reports. There are also major differences in policy implementation—currently, license-restricted cities basically prohibit the transfer of China 4 vehicles. If considering used cars, it is advisable to choose those with higher emission standards, as they will be much easier to resell in the future.