What is the difference between National II and National III
With the increasing awareness of environmental protection and the continuous upgrading of automobile emission standards, many consumers will pay attention to the emission standards of vehicles when buying cars. Although my country's early automobile emission standards have gradually been eliminated, some used cars or old models are still in use. So, what is the difference between the second and third countries? This article will compare in detail in terms of emission standards, implementation time, technical requirements and scope of application.
1. Comparison of emission standards
The main difference between the second and third countries is the restrictions on pollutant emissions. The national third standard is more stringent than that of national second. The specific data are as follows:
| Pollutants | National Second Standard (g/km) | National III Standard (g/km) |
|---|---|---|
| Carbon monoxide (CO) | 2.2 | 1.0 |
| Hydrocarbons (HC) | 0.5 | 0.1 |
| Nitrogen oxides (NOx) | 0.15 | 0.08 |
| Particulate matter (PM) | 0.08 | 0.025 |
2. Implementation time
The implementation time of National II and National III standards is different, the details are as follows:
| standard | Implementation time |
|---|---|
| National II | July 1, 2004 (light vehicle) |
| National III | July 1, 2007 (light vehicle) |
3. Technical requirements
The National III standard is more advanced in technology than the National II, and is mainly reflected in the following aspects:
1.Fuel injection system: National III vehicles usually use electronically controlled fuel injection technology, while National II vehicles are mostly carburetors or mechanical injection.
2.Exhaust gas treatment device: National III vehicles have added oxygen sensors and three-way catalysts to further reduce pollutant emissions.
3.Vehicle Diagnostic System (OBD): National III standard requires vehicles to be equipped with OBD systems to monitor emissions in real time.
IV. Scope of application
At present, the National II and National III vehicles have been gradually eliminated, but they can still be seen in some remote areas or used car markets. It should be noted that many cities have implemented traffic restrictions or elimination policies for vehicles with National II and below, while National III vehicles can still be used normally in some areas. Specific policies vary from region to region. It is recommended to consult the local traffic management department before purchasing a car.
5. Summary
The difference between National II and National III is mainly reflected in emission limits, implementation time and technical requirements. The national third standard is stricter than that of national second, and it makes greater contribution to environmental protection. With the full implementation of the National VI standard, the National II and National III vehicles will gradually withdraw from the stage of history. When purchasing a car, consumers should give priority to models that meet the latest emission standards to reduce the impact on the environment.
The above is the difference between the second and third countries. I hope it will be helpful to you!
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