How to Distinguish Between National 5 and National 6 Vehicle Standards?
2 Answers
The differences between National 5 and National 6 vehicles are: 1. Different emission limits: The National 6a standard requires a carbon monoxide limit of 700 milligrams per kilometer, while the National 6b standard is only 500 milligrams per kilometer; the National 5 standard requires a carbon monoxide limit of 1000 milligrams per kilometer. 2. Different release dates: The National 6 standard was released on June 22, 2018; the National 5 standard was released on September 17, 2013. 3. Different issuing authorities: The National 6 standard was issued by the Ministry of Environmental Protection and the General Administration of Quality Supervision, Inspection, and Quarantine; the National 5 standard was issued by the Ministry of Environmental Protection. 4. Different requirements: National 6 adopts a fuel-neutral principle, meaning that regardless of the fuel type, the emission limits are the same; National 5, in its original phase, had different emission standards for diesel and gasoline engine models.
I previously researched vehicle emission standards, and the main differences between China 5 and China 6 lie in their implementation timelines and emission requirements. China 5 was the fifth-phase standard introduced around 2017, while China 6 is the stricter sixth-phase standard gradually implemented from 2019 onward. For example, China 6 imposes approximately 50% lower limits on nitrogen oxides (NOx) and particulate matter (PM) compared to China 5, meaning China 6-compliant vehicles emit significantly less pollution. To distinguish them, check the environmental information sticker on the vehicle registration certificate: GB17691-2005 indicates China 5, while GB17691-2018 or later denotes China 6. Additionally, China 6 has two stages—6a and 6b—with the stricter China 6b fully enforced from 2023. When purchasing a car, opting for China 6 compliance is ideal, as it benefits both the environment and avoids driving restrictions in some cities. Upgrading older vehicles to China 6 standards requires optimizing the engine and exhaust treatment systems, which increases costs but improves fuel efficiency and long-term savings.
