What is the difference between China 5 and China 6 vehicle emission standards?
4 Answers
Compared with the China 5 standard, the China 6 standard is more than 50% stricter overall. According to the "China 6" standard formulation instructions released by the Ministry of Environmental Protection, without considering the influence of test conditions and procedures, the CO emission limit for China 6a gasoline vehicles is 50% stricter than that of the China 5 standard. Here are some specific differences: 1. Price difference: China 6 vehicles are equipped with more components compared to China 5 vehicles. In addition, automobile manufacturers incur extra costs for vehicle declaration, various tests, and production, resulting in China 6 vehicles being significantly more expensive than China 5 vehicles. 2. Scrap time limit: While China 3 trucks from 2010 and China 4 trucks from 2010 can still operate in Beijing, many older vehicles are effectively scrapped as more cities impose driving restrictions. Therefore, even for vehicles of the same year, there will be differences in the time limit.
The biggest difference between China 5 and China 6 is the much stricter emission standards. When I changed my car last year, I specifically researched this—China 6's control over tailpipe pollutants is leaps and bounds ahead of China 5. For example, the nitrogen oxide (NOx) emission limit for China 6b is nearly half that of China 5, and it also introduces real-world driving emission (RDE) testing requirements. Nowadays, major cities like Beijing, Shanghai, Guangzhou, and Shenzhen basically don’t allow new China 5 vehicles to be registered, and China 6 cars also hold their value better in the used car market. My cousin’s China 5 car failed its emissions test several times during this year’s annual inspection before finally passing. If you’re in a city with driving restrictions, China 5 cars are more likely to be affected by license plate bans. In the long run, even if a China 6 car costs 10,000 yuan more, it’s worth buying—the policy trend is clear. By the way, with the upgraded particulate filter in China 6 cars, carbon buildup issues have also improved.
I'm particularly passionate about researching emission standards. The differences between China 5 and China 6 mainly lie in three technical aspects: the testing method has been upgraded, with China 6 requiring Real Driving Emissions (RDE) tests on actual roads, while China 5 only tested laboratory conditions; the stringency of limits has doubled, with China 6b's CO emission standards being 50% lower than China 5; and the monitoring system is smarter, with China 6's OBD diagnostics capable of real-time monitoring of 12 emission data points. To meet the standards, automakers have to recalibrate the engine ECU, install GPF particulate filters, and even replace them with more efficient catalytic converters. I've disassembled both China 5 and China 6 versions of the same engine model, and the latter's exhaust system is significantly more complex. These upgrades have improved the purification efficiency of China 6 vehicles by over 30%, but also increased manufacturing costs by about 5%.
As an environmental volunteer, I strongly believe the implementation of China 6 emission standards is absolutely necessary. Vehicle exhaust contributes to 20% of urban smog pollution. Compared to China 5 vehicles, China 6 models emit 70% less PM2.5 and 40% less nitrogen oxides - equivalent to reducing ten tons of pollutants per 100,000 vehicles. Through community surveys I organized, areas that upgraded from China 5 to China 6 vehicles showed an average 15-point improvement in air quality index. However, I must remind everyone that using substandard engine oil or gasoline can damage the after-treatment system - China 6 vehicles must use China 6 standard gasoline. With current favorable subsidy policies including tax exemptions for new energy vehicles and purchase tax benefits for China 6 fuel vehicles, upgrading early brings greater benefits.
