What is the National IV Standard?

[GrantDella]

The fourth phase of the national emission standards for motor vehicles, referred to as the 'National IV Emission Standard' or National IV Standard, mainly includes HC, NOx, CO, PM, etc. Through the application of technologies such as the catalytic converter active layer, secondary air injection, and exhaust gas recirculation systems with cooling devices, the emissions from motor vehicles can be controlled and reduced below the specified values. China's National IV emission standards began in 2011 and were implemented in 2018. The national standard requires that the emission levels of various pollutants be about 50% lower than those of the National III standards. The reason China frequently updates its emission standards is that, with the increase in the number of vehicles, the environmental pollution caused by vehicle exhaust has become increasingly severe. Vehicle exhaust contains harmful gases such as carbon monoxide and hydrocarbons, and the emission standards are designed to limit the release of these gases. The national emission standards are mainly based on the European Union standards, with some adaptive modifications made on that basis. Currently, China is in a transitional phase between National V and National VI standards, with many automakers having already launched models that comply with the National VI standards, while National V standard models are being cleared out with substantial discounts.

[OZachary]

I've driven trucks for over a decade and know the National IV emission standards inside out. Simply put, gasoline vehicles registered after July 2011 and diesel vehicles registered after July 2013 must comply. The key metrics are CO emissions not exceeding 1.0g/km and HC below 0.1g/km. My old truck barely passed last year's inspection - the repair shop had to replace the catalytic converter. Some cities are already restricting National IV vehicles in urban areas now. Always check the environmental label when buying used cars, or you might face sudden driving restrictions. These vehicles typically have OBD ports specifically for emission monitoring.

[LaAmy]

Last time I helped my son pick a used car, I specifically researched the China IV emission standard. It belongs to the national fourth-stage emission standard, requiring gasoline vehicles to limit nitrogen oxide emissions to 0.08g/km and diesel vehicles to 0.25g/km. The most obvious identification method is to check the vehicle registration certificate's registration date - those manufactured between 2011 and 2017 are mostly China IV compliant. Here's an interesting fact: some manufacturers had already met the China V standard at that time but still registered and sold them as China IV vehicles. Special attention should be paid to diesel vehicles which require urea solution injection to meet the standard - this ongoing usage cost needs to be factored in.

[RowanAnn]

This is a common question from car owners during repairs. The China IV emission standard requires a reduction of over 50% in particulate matter emissions compared to China III, and diesel vehicles must be equipped with DPF particulate filters. During tailpipe emission testing using the simple driving mode method at inspection stations, gasoline vehicles exceeding 1.1% CO levels will fail. Recently, a 2013 Passat failed due to an oxygen sensor malfunction causing excessive emissions, costing over 3,000 RMB in repairs. Reminder: China IV vehicle inspections are becoming increasingly strict, so it's best to warm up the car for ten minutes before heading to the testing line for annual inspection.

[LeDaniela]

A used car evaluator tells you: The implementation period of China IV emission standards was from 2011 to 2017. The exhaust emission test mainly focuses on three items—hydrocarbons, nitrogen oxides, and particulate matter. There's a simple way to identify: check the vehicle nameplate; models marked with IV are China IV compliant. Currently, such cars in the used car market are priced about 15% lower than China V vehicles. It's worth noting that some provinces have already banned the cross-city transfer of China IV vehicles, so check local policies when buying out-of-town cars. Regularly cleaning the throttle body and replacing the air filter can effectively reduce emission levels.

[BethanyMarie]

During my work at the environmental protection department, I came across standard documents. The China IV regulations require gasoline vehicles to be equipped with an OBD (On-Board Diagnostics) system to monitor emission devices in real time. According to actual test data, compliant vehicles reduce emissions by over 30% compared to China III vehicles. Currently, there are traffic restrictions for such vehicles in the Beijing-Tianjin-Hebei region, and Hangzhou started prohibiting China IV diesel trucks from entering the ring expressway during daytime last year. If the vehicle is well-maintained and the three-way catalytic converter functions properly, it can still be driven for several more years. However, in the long run, the China VII standard is already under development, and emission controls will only become stricter.