
The China 4 emission standard started in 2011 and was in effect until the China 5 standard was implemented in 2018. Therefore, vehicles produced between 2011 and 2017 were all under the China 4 standard. The China 4 standard requires the emission levels of various pollutants to be approximately 50% lower than those of the China 3 standard. The specific implementation times of the China 4 standard for different vehicle types are as follows: 1. The China 4 standard for diesel vehicles over 3.5 tons, originally scheduled to be implemented on January 1, 2010, was postponed by two years. This means that from January 1, 2012, diesel vehicles that did not meet the China 4 standard requirements could not be sold or registered; new compression-ignition engines that did not meet the China 4 standard requirements could not be sold or put into use. 2. For diesel vehicles under 3.5 tons, the implementation of the China 4 standard was postponed by three years, taking effect on July 1, 2013. 3. From January 1, 2011, gas-fueled spark-ignition engines and vehicles that did not meet the China 4 standard requirements could not be sold or registered.

The China 4 emission standards actually had two critical implementation dates. The China 4 standards for light-duty vehicles officially took effect in July 2010, requiring all newly manufactured passenger cars to comply for sale. Heavy-duty vehicles faced a much later deadline, with full enforcement not beginning until July 2013. A mechanic friend told me many truck drivers rushed to replace their vehicles before the cutoff. I recall visiting an auto show that year where salespeople heavily promoted newly launched SUVs meeting China 4 standards—after all, with upgraded exhaust treatment systems, these vehicles emitted nearly 50% fewer pollutants than China 3 models. Looking back, China 4 marked a pivotal turning point in China's environmental progress, laying the groundwork for subsequent China 5 and China 6 standards.

I remember this quite clearly. Back in 2010 when I bought my first car, I did some research. The salesperson pointed to the environmental label and said it was a China IV compliant vehicle, and all new cars manufactured after July had to meet this standard. However, it was different for heavy-duty trucks - the nationwide mandatory implementation of China IV standards for trucks wasn't enforced until summer 2013. I recall news reports saying the Pearl River Delta region had piloted the standards earlier. Interestingly, the China IV implementation caused some chaos in the used car market for a while, with some areas outright prohibiting the transfer of China III vehicles. You can still see China IV vehicles on the road today, though many cities no longer allow non-local China IV vehicles to be registered there. If you're considering buying an older car now, it's best to check local policies, as environmental requirements are getting stricter.

Regarding the implementation year of China IV standards, light passenger vehicles were nationally mandated from July 1, 2010. I was interning at an automotive plant back then, and the assembly line process for installing three-way catalytic converters suddenly became more complex. However, heavy-duty diesel vehicles were delayed until 2013 for compliance, primarily because diesel exhaust treatment technologies were harder to breakthrough. China IV vehicles have a distinctive feature: a blue label on the fuel tank cap. Recently, while helping a friend shop for used cars, I noticed many 10-year-old China IV vehicles can still be normally transferred in numerous cities, though they may face emission restriction impacts soon.


