What is the difference between National 4 and National 5?
5 Answers
The differences between National 4 and National 5 emission standards for vehicles are: 1. Different nitrogen oxide (NOx) emission limits: National 4 sets the NOx emission limit at 0.08 milligrams per cubic meter, while National 5 reduces it to 0.06 milligrams per cubic meter. 2. Different standard codes: National 4 follows the GB18352.32005 standard, whereas National 5 complies with GB18352.52013. Methods to distinguish between National 4 and National 5 vehicles include: 1. Checking the vehicle's fuel consumption label; 2. Inspecting the vehicle's nameplate; 3. Examining the engine model number; 4. Looking for the environmental protection mark; 5. Visiting the official motor vehicle environmental protection website.
Recently, many folks have been asking about the differences between China 4 and China 5 emission standards, so I'll share my personal experience as a car mechanic. China 4 was introduced around 2011, while China 5 was upgraded around 2017. The most noticeable difference is stricter exhaust regulations—China 5 vehicles emit one-third less carbon monoxide and half the nitrogen oxides compared to China 4. Technologically, China 5 vehicles are more advanced, commonly equipped with OBD monitoring systems and additional sensors in the exhaust pipes. Fuel quality has also improved significantly, with today's 95-octane gasoline being much cleaner. In practice, China 5 cars are more eco-friendly, and in big cities, China 4 vehicles are often restricted from entering the second ring road. If you're buying a used car, make sure to check the emission label—I got burned last year when I bought a Passat without paying attention to this.
My colleague recently dealt with the headache of upgrading from China 4 to China 5 emission standards. The difference lies in the details of control—China 5 tightened particulate matter limits for diesel vehicles by over 80%. The onboard diagnostic system evolved from a basic version in China 4 to real-time monitoring, making the malfunction indicator light more sensitive. The key issue is the cost of ownership—China 5 vehicles require redesigned fuel pumps and injectors, pushing maintenance costs up by 20%. Data from suburban inspection stations here shows that China 5 vehicles have a 15% higher first-time pass rate. Don’t underestimate those improvements—replacement parts could cost hundreds more.
The core difference between China 4 and China 5 standards lies in the adjustment of emission limits. China 5 reduces the combined HC+NOx value to 0.16g/km, while China 4 remains at 0.3g. It newly adds PN (particle number) control for particulate matter, which particularly affects gasoline vehicles. Technologically, it requires installation of DPF (Diesel Particulate Filter) and upgrades to three-way catalytic converters. Vehicles newly registered after 2018 must meet China 5 standards, and now the price difference for used cars can reach up to 10,000 yuan.
Two years ago, I helped a neighbor pick a car and researched this. The China 5 standard mainly tightened pollution control for diesel vehicles, reducing the PM limit from 0.025 grams to 0.0045 grams. For gasoline vehicles, the focus was on managing evaporative emissions, requiring sealed fuel tank modifications. The diagnostic system could remotely monitor emission status. The actual impact was significant: China 4 vehicles faced transfer restrictions, and cities like Shanghai directly imposed driving bans. As car owners, we could feel that China 5 vehicles had more stable idling, but low-ash engine oil had to be used.
