What is the vehicle exhaust emission standard?

[SpencerRose]

Vehicle exhaust emission standard is the China IV standard. The following are the harmful substances and hazards of vehicle exhaust: Harmful substances in vehicle exhaust: Vehicle exhaust contains hundreds of different compounds, among which the pollutants include solid suspended particles, carbon monoxide, carbon dioxide, hydrocarbons, nitrogen oxides, lead, sulfur oxides, etc. Hazards of vehicle exhaust: While directly endangering human health, exhaust also has profound impacts on the living environment of humans. Sulfur dioxide in the exhaust has a strong irritating odor and can easily lead to "acid rain" when reaching certain concentrations, causing soil and water sources to acidify and affecting the growth of crops and forests.

[OCamila]

I've been repairing cars for over a decade, and emission standards are thresholds set by the government for vehicle exhaust. The higher the numbers like China V and China VI, the stricter the requirements. They mainly regulate four things: toxic gases like carbon monoxide in the exhaust, unburned hydrocarbons from incomplete combustion, nitrogen oxides produced by intense combustion, and PM particulate matter. Nowadays, China VI-compliant vehicles on the road are equipped with purifiers like three-way catalytic converters, and some diesel vehicles even have additional DPF particulate filters to make the exhaust cleaner. During annual inspections, a tube is inserted to measure emissions, and vehicles that exceed the standards must either be repaired or scrapped. Currently, China VIb-compliant vehicles have exhaust as clean as boiled water, whereas a decade ago, black smoke from China IV-compliant vehicles was common.

[OCora]

Last time I took my old car for the annual inspection, it almost failed the emissions test, which made me realize how important emission standards are. Simply put, the government sets rules to restrict heavily polluting vehicles. Many cities now impose restrictions on older vehicles like China III and China IV models, barring them from urban areas. When buying a used car, pay special attention to this. My neighbor bought a cheap China III pickup truck, and now it can only be used as a farm vehicle. New China VI vehicles have sensors in the exhaust pipe for real-time monitoring—if emissions don’t meet standards, the fault light comes on immediately. I heard that China VII might be introduced by 2030, and by then, even gasoline cars might struggle to stay on the road. Some cities now offer green license plates and no restrictions for new energy vehicles, pushing everyone to upgrade their cars.

[MacLiam]

Anyone in automotive R&D knows there are three major global emission systems. Europe's Euro standards are the most established, and China's China 6 is essentially modeled after Euro 6. California in the U.S. is particularly stringent, having established the world's toughest CARB standards independently. Our China 6b has actually surpassed Europe and caught up with the U.S., with nitrogen oxide limits 30% lower than those in the U.S. The testing methodology has also been upgraded to WLTC dynamic testing, simulating real-world scenarios like traffic jams and hill climbs. The most challenging part is the RDE real-driving emissions test, where vehicles must carry testing equipment on highways and national roads—if the engine temperature doesn't rise sufficiently, it's easy to exceed standards. Automakers now face an additional cost of over 8,000 yuan just for the exhaust after-treatment systems.

[OBarrett]

I remember when Beijing first implemented the China I emission standards in 2000, carburetor-equipped vehicles were still common on the streets. Over the past two decades, the emission standards have been upgraded six times, with each upgrade cutting tailpipe pollution by half. The China III standard eliminated 67% of nitrogen oxides, while China VI further reduced carbon monoxide limits to 0.3g/km – roughly equivalent to the pollution from half a cigarette. Today's new vehicles are equipped with Gasoline Particulate Filters (GPF) that are even denser than face masks, capable of trapping 90% of PM2.5 particles. Recently, there's been talk of developing carbon-neutral gasoline vehicles, potentially requiring even gasoline car exhaust pipes to be fitted with CO2 collectors after 2030.

[VanIsla]

Three key points to note when preparing to buy a car: First, check whether the environmental label indicates China 6a or 6b, with 6b being three times stricter than 6a. Second, verify the standard by checking the supplementary page of the vehicle registration certificate. Third, clarify the local policies. In places like Tianjin and Hebei, since last year, non-local vehicles below China 6 standards have not been allowed to be registered. The used car market is even more complicated—some dealers may falsify a China 4 vehicle as China 5, but the truth will be revealed during the inspection. It's recommended to use the 'Motor Vehicle Environmental Protection Website' to check the actual emission standards of the vehicle. In the long run, it might be better to buy an electric vehicle to completely avoid exhaust emission concerns, especially since the China 7 standard may come into effect as early as 2025.