How to Distinguish Between China 5 and China 6?

[MacReagan]

The differences between China 5 and China 6 emission standards are as follows: Different emission standards: China 6 emission standards are more than 30% stricter than China 5. Excluding the influence of working 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 5 standard was implemented nationwide on January 1, 2017. The China 6 standard was implemented on July 1, 2019. Different principles: Under the China 5 standard, diesel and gasoline vehicles had different emission standards. However, China 6 adopts a fuel-neutral principle, meaning the emission limits are the same regardless of the fuel type. Different issuing departments: The China 5 standard was issued by the Ministry of Environmental Protection. The China 6 standard was jointly issued by the Ministry of Environmental Protection and the General Administration of Quality Supervision, Inspection, and Quarantine. Different letter representations: China 5 is represented by 'V,' while China 6 is represented by 'VI.' Different monitoring requirements for plug-in hybrid electric vehicles: Compared to China 5, China 6 has improved monitoring requirements for plug-in hybrid electric vehicles, including energy storage systems, thermal management systems, brake regeneration, drive motors, generators, and other regulations. China 5 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 6 has two standards: China 6a and China 6b, as follows: China 6a 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 6b 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 6 emission policy, although China 5 vehicles are not currently restricted in normal use (no driving bans or license plate restrictions), their resale value will be significantly impacted. For truck 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 6 vehicles, which have a longer service life and more road rights, offer greater advantages.

[DiLane]

I just researched this a couple days ago when helping a friend inspect a car. The most straightforward way is to check the 10th letter of the VIN: models starting with P or N are mostly China 5, while R and S usually indicate China 6. China 6 vehicles often have a small blue label on the rear saying 'China VI'. Remember that light and heavy gasoline vehicles purchased after July 2019 were mostly upgraded to China 6, while diesel vehicles followed about half a year later. The key difference is in the emission testing equipment during annual inspections - China 6 testers can detect finer particle counts, which is why our older vehicles clearly spend less time in line at inspection stations than China 6 cars. By the way, when buying used cars, it's especially important to verify on the environmental protection website, as some coastal cities no longer allow China 5 vehicles to be transferred.

[DiXavier]

Over the years in the used car business, I've noticed a pattern: China 6 vehicles have an extra GPF (Gasoline Particulate Filter) layer in the exhaust system, and the inner walls of the exhaust pipes are noticeably cleaner than China 5 vehicles. China 6B models are particularly finicky—they require low-ash SP-grade engine oil. Last time, a customer used regular oil and the fault light came on immediately. In the environmental compliance list, 'PN limit 6.0×10^11' indicates China 6A, while '6.0×10^11' alone means China 6B. Last year, I acquired a stock China 5 vehicle that was over 8,000 yuan cheaper than the same model in China 6, but it couldn't be registered in cities with migration restrictions. Nowadays, I always bring an OBD scanner to check the OBD protocol version when purchasing cars—China 6 vehicles have significantly more complex protocols.

[GrahamAnn]

Emissions depend on core parameters. China 6 slashes CO limits to one-third of China 5 levels, with stricter controls even during cold starts in real-world driving. Our lab requires new equipment for tailpipe testing - China 6 vehicles alone have three additional sensors. The biggest headache is the OBD system's mandatory online fault code reporting. When calibrating China 6 engines last year, the data volume quadrupled compared to China 5. Service stations now stock special diagnostic tools for GPF regeneration, and even clearing fault codes costs more than before.

[Nicola]

The difference in usage costs is quite significant. China-6 compliant vehicles require 95-octane gasoline and new standard engine oil. My China-5 car purchased two years ago costs just over 300 yuan per service, while my neighbor's China-6 car spends 600 yuan just on replacing the dedicated GPF filter. In the used car market, China-6 models hold their value much better—for example, in the Pearl River Delta cities, China-5 cars sell for about 10,000 yuan less than China-6 models. Restricted driving zones are another drawback; Zhengzhou started enforcing China-5 vehicle restrictions via gantries last year. If you frequently travel out of town, buying a China-6 compliant car is more reliable, and most newly released hybrid vehicles now meet at least the China-6B standard.

[DeAllie]

The implementation timeline of policies can be confusing. China 6 standards are divided into two phases: In July 2019, light gasoline vehicles first transitioned to China 6A, while the Yangtze River Delta and Pearl River Delta regions directly adopted China 6B. By July 2020, all gasoline vehicles nationwide were required to meet China 6A standards, with China 6B fully rolled out only in July this year. The most accurate way to distinguish is by checking the vehicle registration date on the driving license – cars purchased after 2021 are mostly China 6B compliant. Currently, in cities like Beijing and Shanghai, even temporary license plates are not issued for China 5 vehicles. Special attention is needed when purchasing parallel imported vehicles – some modified Middle East versions can pass China 5 but fail to meet China 6 standards.