Differences Between China 3 and China 4 Motorcycle Standards

[StXavier]

The main differences lie in sulfur content and pollutant emission reductions. Below is an introduction to the distinctions between China 3 and China 4 standards: 1. The most significant difference between China 4 and China 3 motorcycles is the substantial improvement in emission standards, which leads to changes in motorcycle pricing and performance. To meet the emission requirements, China 4 motorcycles have replaced traditional carburetors with electronic fuel injection systems and upgraded their exhaust systems. 2. The China 4 motorcycle emission standard was implemented on July 1, 2019. This standard represents the fourth phase of national motor vehicle pollutant emission regulations, targeting pollutants such as HC (hydrocarbons), NOx (nitrogen oxides), CO (carbon monoxide), and PM (particulate matter). Through catalytic converters, emissions are controlled and reduced to levels below specified limits. 3. The China 4 standard primarily focuses on controlling harmful gas content in exhaust emissions. Therefore, all China 4 motorcycles utilize electronic fuel injection technology to reduce pollutant emissions.

[DelLucas]

The main difference between China III and China IV motorcycles lies in emission control technology. China IV models must be equipped with electronic fuel injection (EFI) systems instead of carburetors, enabling precise fuel delivery and higher engine combustion efficiency. Their pollutant emission limits are significantly stricter than China III - for example, the CO limit drops from 2.0g/km to 1.0g/km, while HC and NOx emissions must be reduced by over half. New vehicles also require onboard diagnostics (OBD) systems to monitor exhaust in real-time and trigger maintenance alerts when exceeding standards. Fuel tank sealing requirements are enhanced to prevent gasoline vapor leakage. China IV motorcycles typically operate more quietly with reduced vibration, though they cost several hundred to over a thousand yuan more.

[JuliannaMarie]

Last year I upgraded from a China III to a China IV scooter, and noticed the China IV starts much faster, even in cold weather without needing the choke. The most noticeable difference is fuel consumption—it saves about 0.5 liters per 100 kilometers. The China IV model has an additional catalytic converter in the exhaust pipe, making the emissions virtually odorless, but maintenance requires more care—avoid high-pressure washing near the exhaust pipe. During annual inspections, the China IV passes easily, while my friend's China III scooter often fails emissions tests. However, China IV sensors are more delicate; replacing an oxygen sensor can cost over 300 yuan. I recommend choosing reputable brands for China IV scooters, as parts are easier to find.

[HadleyRose]

The China IV standard has significantly reduced motorcycle pollution. Compared to China III motorcycles, a China IV motorcycle emits 26 kg less carbon monoxide annually, with hydrocarbon emissions reduced by approximately 38%. It has contributed to air quality improvements in major cities like Beijing, particularly in more effective control of ozone pollution during summer. The policy also drives upgrades, as China III motorcycles now depreciate faster in the second-hand market, and many regions mandate China IV standards for new purchases. Buying a China IV motorcycle means taking on more environmental responsibility—every little bit counts. Of course, there are drawbacks, such as insufficient space in older motorcycle models to retrofit China IV devices, making upgrades difficult.

[OEverly]

From a car repair perspective, the differences between China III and China IV standards are significant. For China III carburetor systems, you can clean and adjust them yourself at a cost of around 50 RMB. However, China IV electronic fuel injection systems require professional equipment for detection, computer diagnosis of fault codes, and replacing a set of injectors costs about 700-800 RMB. Parts supply is also more complicated - China III components are widely available, while China IV parts often require ordering original manufacturer components. On the plus side, China IV vehicles accumulate less engine carbon deposits, typically not needing throttle body cleaning within 30,000 km. In the used car market, China IV vehicles command about 10% higher prices, but after five years, their maintenance costs will certainly be higher than China III vehicles.