On June 1, 2026, the Ministry of Ecology and Environment (MEE) publicized a notice to announce the publication of the sector environmental standard HJ 1477-2026 Technical specification for real driving emissions measurement of light-duty Vehicles, which will take effect on September 1, 2026. This newly drafted standard is formulated to implement the Ecological and Environmental Code of China and to control pollutant and greenhouse gas emissions from vehicles under actual driving conditions.

The development of the standard was initiated in 2019 under an assignment MEE, with the Chinese Research Academy of Environmental Sciences (CRAES) as the lead drafting unit. During the drafting process, the continuous evolution of international RDE test technologies, particularly the proposal in the Euro 7 draft to adopt RDE as the primary emission control approach, prompted a shift in the standard’s orientation from initially supporting the implementation of China VI RDE requirements to aligning with European RDE regulations and serving primarily the next-stage emission standards. The drafting working group (WG) simultaneously carried out validation work on relaxed boundary conditions, short trips, and removal of the CO₂ window, and ultimately defined this standard as a test method standard referenced by GB 18352 series (Limits and measurement methods for emissions of pollutants from light-duty vehicles).

The necessity for this standard is explained by the drafting WG as:

-   Address the change in regulatory approach, as real‑driving emission testing should be a key complement to laboratory testing;

-   Meet the regulatory challenges posed by new technologies, especially hybrid vehicles, whose diverse driving modes and state‑of‑charge conditions are not fully covered by current evaluation methods;

-   Resolve disputes in enforcement and arbitration, as the existing RDE procedure suffers from poor repeatability due to insufficient control over PEMS equipment requirements and environmental conditions, leading to considerable controversy in compliance testing.

-   The current RDE provisions of China VI are inadequate in terms of pollutant coverage, environmental boundary conditions, test procedures, data processing methods, and equipment management, making it necessary to establish a dedicated standard to fulfil environmental management needs.

The technical route for formulating the standard was based on a thorough investigation of real‑driving emissions from China VI light‑duty vehicles, taking into account the regulatory needs of the competent environmental authority, and combining domestic and international control approaches with industrial technological capabilities and development trends. The main contents were determined accordingly, and joint validation work with industry enterprises was carried out on pollutant measurement methods, equipment verification, test procedures, and data processing methods, leading to the preparation of the standard text and the accompanying compilation note.

This standard consists of six chapters, and the main contents include:

-   Technical requirements: specify the pollutants to be measured, the technical requirements for PEMS equipment, and the test boundary conditions.

-   Test procedure: provide detailed procedures including pre‑conditioning, soaking, and the actual test.

-   Test validity verification and emission results calculation: cover zero and span drift checks of analyzers, verification of trip dynamics and cumulative positive altitude gain.

-   Four normative annexes: respectively prescribe PEMS technical specifications, the method for verifying trip dynamics, the procedure for calculating cumulative positive altitude gain, and the emission calculation method.

Compared with the RDE requirements in China VI, this standard introduces updates and adjustments in the following aspects:

-   Further expanding the scope of pollutant and vehicle control and refining the general RDE test requirements;

-   Further relaxing test environmental boundaries to promote emission control under real‑world conditions;

-   Further standardizing test procedures and strengthening requirements for cold‑start and hot‑start emission tests;

-   Further refining vehicle test requirements based on technology‑neutral principles to cover diversified automotive technologies;

-   Further optimizing real‑driving data processing methods to scientifically reflect actual vehicle emissions;

-   Further improving requirements for test equipment and final reports to strengthen overall quality control covering equipment, process, and data management.

Foreign stakeholders are advised to notice that, in regards of implementation, and for need for consistency with the overall standard system, this standard will serve as a test method standard referenced by GB 18352 series and will be implemented in phases through normative reference. Certain requirements, such as those for PEMS equipment that do not involve upgrades to vehicle emission control technologies, are recommended to be implemented in advance through amendments to the China VI regulations.