How to distinguish between National V and National VI?

[Elias]

National V and National VI can be distinguished as follows: National V refers to the China Phase 5 vehicle emission standards, while VI refers to the China Phase 6 emission standards. National V, or the China Phase 5 vehicle pollutant emission standards, imposes stricter limits on pollutants such as nitrogen oxides, hydrocarbons, carbon monoxide, and particulate matter emitted by vehicles. From Phase 1 to Phase 5, each upgrade in standards reduces vehicle pollution by 30% to 50%. The full name of the National VI standard is the China Phase 6 vehicle pollutant emission standards, which regulate the levels of harmful gases such as carbon monoxide, hydrocarbons, nitrogen oxides, particulates, and soot emitted from vehicle exhaust.

[DiAdeline]

Last time when helping a friend choose a car, I specifically researched the differences between China 5 and China 6 emission standards. The simplest way is to check the vehicle's environmental protection list and the conformity certificate, which clearly state the emission standard code. China 6 is divided into two phases, a and b, with much stricter limits than China 5. For example, the carbon monoxide emission limit is reduced from 1 gram/km to 0.5 gram/km. China 6 vehicles must pass real-world driving emission tests and actively monitor the status of the emission system. In major cities like Beijing and Shanghai, only China 6 vehicles can be registered now, and even used China 5 vehicles are not allowed to be transferred. Last year, two China 5 cars in our neighborhood had to be sold to third- or fourth-tier cities. Remember to directly ask the salesperson about the specific emission phase when buying a new car—only China 6b is truly compliant, so don’t be fooled.

[MaximusLynn]

When helping my son pick out a new car, I noticed that the exhaust pipe structure of China VI vehicles is significantly different, with a larger three-way catalytic converter and an added particulate filter inside. The mechanic mentioned that China VI engines have more precise programming, with idle speeds generally about 100 RPM lower. The gas station attendant told me that China VI vehicles must use fuel labeled 'VIA/VIB,' otherwise the emission system will trigger an alarm. The most straightforward way to check is by looking at the 10th digit of the vehicle identification number (VIN): 'L' indicates China V, while 'M/N' indicates China VI. Now, the transfer of out-of-town license plates is strictly inspected—our neighbor Lao Wang's China V car was rejected three times by the DMV and ultimately sent back.

[Sherri]

The differences mainly lie in three aspects: the emission standards have become twice as stringent, the testing method has been upgraded from laboratory conditions to real-road monitoring, and the fault diagnosis system now requires vehicles to automatically report issues. The China 6 standards have tightened requirements for gasoline vehicles by 50%, and for diesel vehicles, the increase is even up to 77%. Last time, Xiao Zhang at the inspection station showed me that China 6 vehicles have a dedicated emission fault light on the dashboard. The production date is also a clue—most domestically produced vehicles manufactured after 2019 comply with China 6 standards. Many cities have different traffic restriction policies; for example, Hangzhou prohibits China 5 vehicles from entering the area within the ring expressway during morning and evening rush hours. It's recommended to use the official app and enter the VIN for the most accurate information.