What is the difference between National 4 and National 5 standards?

[MayaLynn]

The difference between National 4 and National 5 standards lies in their upper limits for sulfur content. Here are the relevant details: 1. The sulfur content limit for National 4 standard gasoline is 10mg, while for National 5 standard gasoline it's 50mg. National 5 imposes stricter controls on nitrogen oxides compared to National 4, with National 5 setting the emission limit at 25%. 2. The National 4 emission standard represents China's fourth-phase motor vehicle pollutant emission requirements. Major automotive pollutants include HC, NOx, CO, and PM. These standards are achieved through technologies such as improved catalytic converter active layers, secondary air injection, and exhaust gas recirculation systems with cooling devices.

[VonHarley]

I'm looking at the difference between China 4 and China 5 standards from a car repair perspective. Simply put, the exhaust purification requirements are higher. China 5 is about 40% stricter than China 4, especially in controlling diesel vehicles. For example, the nitrogen oxide limit was 190mg/km under China 4, but China 5 slashes it to 60mg. The same goes for gasoline vehicles - sulfur content in gasoline was 150ppm under China 4, but China 5 reduces it to below 10ppm, so new cars now require 95-octane gasoline to meet cleanliness standards. The key upgrade is in the emission system - China 5 requires particulate filters, which need regular cleaning and significantly increase maintenance costs. It's great for the environment, but it does raise vehicle ownership costs a bit.

[Drew]

As a used car dealer, I know best that China 4 and China 5 emissions standards directly affect vehicle transfers. The China 5 standard was fully implemented after 2017, and cities like Beijing, Shanghai, Guangzhou, and Shenzhen stopped allowing China 4 vehicles to be registered long ago. Since last year, many cities have restricted transfers, and in our city, China 4 vehicles can only be transferred locally. Pay special attention to this when buying cars—for example, a Volkswagen Lavida in similar condition can sell for 3,000 to 4,000 yuan more if it meets China 5 standards. Before buying a used car, check the environmental label—the emission standard is clearly marked on the nameplate under the hood: 'China V' means 5, and 'China IV' means 4. Those China 4 vehicles from the transition period now often fail emissions tests during annual inspections.

[TylerFitz]

From an average user's perspective, driving a China 5 vehicle doesn't feel much different. Officially, fuel consumption is said to decrease by 5%, but in actual driving, the difference isn't noticeable. The main distinction lies in environmental testing. Last year, when I took my old China 4 vehicle for inspection, the exhaust was tested three times before passing, while a new China 5 vehicle next to me passed on the first try. The gasoline used has also changed; now, the 92-octane gasoline at gas stations meets the China 5 standard. In the long run, if you're planning to change cars, it's obviously better to buy a China 5 model—it holds its value better and is more worry-free, and in a couple of years, there might be driving restrictions.

[BethanyRose]

Technically, China 5 standards mainly strengthened three aspects: added SCR system to control nitrogen oxides, equipped gasoline vehicles with ORVR anti-evaporation devices, and mandated TPMS for all vehicles. The OBD diagnostic system became more sensitive, immediately triggering the malfunction indicator light when emissions exceed limits. For China 4 vehicles, restarting would clear the light, but China 5 requires dealership visits to reset codes. The most troublesome cost is maintenance - upgrading the three-way catalytic converter replacement now costs 5,000-6,000 yuan.

[SanJudah]

A parent who recently purchased a car shared: The main differences lie in policy restrictions. For example, in Chengdu, only China 5 vehicles can be registered, forcing me to sell my China 4 car at a low price. New energy vehicle subsidies also vary—trading in a China 4 car gets you 5,000 yuan, while a China 5 car gets 8,000 yuan. When traveling with kids, note that many scenic spots' parking lots now restrict China 4 vehicles. The salesperson mentioned that China 5 vehicles have improved durability, lasting up to 160,000 km—60,000 km more than China 4. In the long run, it's better to opt for China 5 when upgrading, as policy pressures are quite evident.