What are the differences between China V and China VI emission standards?

[DeElizabeth]

The differences between China V and China VI emission standards are as follows: Different emission standards: The China VI emission standard is more than 30% stricter than China V. Excluding the influence of operating conditions and testing, gasoline vehicles' carbon monoxide emissions are reduced by 50%, total hydrocarbons and non-methane hydrocarbons emissions are reduced by 50%, and nitrogen oxide emissions are reduced by 42%. Different implementation times: The China V standard was implemented nationwide on January 1, 2017, as the fifth stage of national motor vehicle emission standards. The China VI standard has been implemented since July 1, 2019. Different principles: During the China V phase, diesel and gasoline vehicles had different emission standards, but China VI adopts a fuel-neutral principle, meaning that regardless of the fuel type, the emission limits are the same. Different issuing departments: The China V standard was issued by the Ministry of Environmental Protection. The China VI standard was issued by the Ministry of Environmental Protection and the General Administration of Quality Supervision, Inspection, and Quarantine. Different letter representations: China V is represented by "V," and China VI is represented by "VI." Different monitoring requirements for plug-in hybrid electric vehicles: Compared to China V, China VI has improved monitoring requirements for plug-in hybrid electric vehicles, including regulations on energy storage systems, thermal management systems, brake regeneration, drive motors, generators, etc. The China V standard limits are as follows: Gasoline vehicles must not emit more than 1,000 milligrams of carbon monoxide per kilometer driven. Gasoline vehicles must not emit more than 68 milligrams of non-methane hydrocarbons per kilometer driven. Gasoline vehicles must not emit more than 60 milligrams of nitrogen oxides per kilometer driven. Gasoline vehicles must not emit more than 4.5 milligrams of PM (particulate matter) per kilometer driven. China VI has two standards: China VIa and China VIb, as follows: China VIa standard limits: Gasoline vehicles must not emit more than 700 milligrams of carbon monoxide per kilometer driven. Gasoline vehicles must not emit more than 68 milligrams of non-methane hydrocarbons per kilometer driven. Gasoline vehicles must not emit more than 60 milligrams of nitrogen oxides per kilometer driven. Gasoline vehicles must not emit more than 4.5 milligrams of PM (particulate matter) per kilometer driven. China VIb standard limits: Gasoline vehicles must not emit more than 500 milligrams of carbon monoxide per kilometer driven. Gasoline vehicles must not emit more than 35 milligrams of non-methane hydrocarbons per kilometer driven. Gasoline vehicles must not emit more than 35 milligrams of nitrogen oxides per kilometer driven. Gasoline vehicles must not emit more than 3 milligrams of PM (particulate matter) per kilometer driven. Affected by the China VI emission policy, although China V vehicles are not currently restricted from normal use, such as road restrictions or license plate limitations, their resale value will be significantly impacted. For car owners, if they purchase a truck on loan for cargo transport, the vehicle's depreciation after repaying the loan is equivalent to the net profit earned during that period. A higher residual value means more profit for the owner. Therefore, from this perspective, China VI vehicles, which have a longer service life and more road rights, are more advantageous.

[MacJoel]

Last month, I finally understood this issue when accompanying a friend to choose a used car. The most obvious difference between China 5 and China 6 is the strictness of emission standards, with China 6 imposing much tighter limits on pollutants. For example, the carbon monoxide limit was directly halved from 1000 mg per kilometer under China 5 to 500 mg. The testing methods were also upgraded, with China 6 replacing the outdated NEDC with the WLTC cycle test and adding real-world driving emission tests. China 6 vehicles must be equipped with particulate filters to trap fine particles in the exhaust. It's important to note that China 6 is further divided into two phases, a and b, and all new cars currently on sale must meet the stricter China 6b standards. When buying a used car, pay attention to this, as China 5 vehicles may face restrictions on relocation in the future.

[VonPenelope]

In simple terms, it's an environmental upgrade, and the China 6 standards are much stricter. My buddy who runs a repair shop complains about it every day. China 6 vehicles have an additional particulate filter (GPF) in the exhaust pipe, which often gets clogged and triggers the engine warning light. The fuel requirements are also different—using 92-octane gasoline in a China 6 car can easily cause the warning light to come on. Nowadays, buying a new car means you have to choose a China 6 model, or you won't be able to register it. In the used car market, China 5 vehicles are noticeably cheaper, and many cities restrict the transfer of China 5 cars. In the long run, China 6 cars will have better resale value, but they require more meticulous maintenance, especially using genuine oil on time.

[StephenAnn]

From a daily usage perspective, there are three key differences: First, you need to be careful with fuel selection - China VI vehicles are best suited for 95 octane or higher gasoline, otherwise they're prone to throwing fault codes. Secondly, the particulate filter in China VI vehicles requires regular highway driving to burn off carbon deposits; frequent short city trips will trigger clogging warnings. Lastly, the power tuning tends to be more conservative to meet emission standards, resulting in slightly weaker engine output. When I recently drove my friend's China V and China VI versions of the same model, the China VI version's throttle response was noticeably slower. Additionally, maintenance costs are higher - replacing an exhaust pipe with GPF can cost three to four thousand yuan.

[AngelaFitz]

The key difference lies in the environmental data requirements. China 6 reduces the nitrogen oxide emission limit from 60 mg/km under China 5 to 35 mg/km, with non-methane hydrocarbons tightened by nearly 50%. The testing method has been changed to the globally unified WLTC cycle, which is closer to real-world driving conditions. A new 240,000-kilometer durability test has been added to ensure stable emission performance. It also introduces an OBD online monitoring system for the first time, which directly alerts when exhaust emissions exceed standards. When purchasing a car, look for the China 6b label, as some early China 6a models may face obsolescence risks. Also, use low-ash engine oil for refilling, otherwise, the GPF is prone to clogging.

[Kara]

Just studied this last week. The biggest difference with China 6 is the change in control strategy, replacing China 5's normal temperature cold-start test with a cold-start test at -7 degrees Celsius. The pollutant testing items now include nitrous oxide, and there's also a requirement to monitor fuel evaporation emissions. The most troublesome part is the OBD system—the engine light flashes like crazy even with slight exhaust overruns. When choosing a car, check the onboard environmental compliance list to distinguish between China 6a and 6b stages. Northern car owners should pay special attention: China 6b models might occasionally shake a bit during cold starts in extreme cold—this is the GPF's built-in exhaust temperature protection strategy and not a fault.