China's Stage 6 emission standard for new light-duty vehicles (final rule)

Published: 2017.03.16

Hui He, Liuhanzi Yang

On December 23, 2016, the Ministry of Environmental Protection (MEP) of the People’s Republic of China released the final rule of the Stage 6 Limits and Measurement Methods for Emissions from Light-Duty Vehicles1 (GB18352.6—2016; hereafter referred to as the China 6 standard or China 6). This standard applies to light-duty vehicles (M1, M2, and N1 categories up to 3,500 kg of maximum mass per the European regulatory classification) powered primarily by gasoline or diesel. The China 6 standard will take effect beginning on July 1, 2020.

Unlike the previous standard phases, which closely follow the European emission standards, the China 6 standard combines best practices from both European and U.S. regulatory requirements in addition to creating its own. Specifically, the standard features:

  • Two sets of fuel-neutral emission limits—China 6a and 6b—for air and climate pollutants, including carbon monoxide (CO), total hydrocarbons (THC), nitrogen oxides (NOx), particulate matter (PM), particle number (PN), and nitrous oxide (N2O);
  • A shift from the New European Driving Cycle (NEDC) to the more representative and dynamic World Harmonized Light Vehicle Test Cycle (WLTC) and more rigorous World Harmonized Light Vehicle Test Procedures (WLTP);
  • Adoption of real-world driving emission (RDE) testing and requirements based on the European RDE provision passed in March 2016, with modifications that address the unique driving conditions in China for both type test and in-use conformity;
  • Enhanced on-board diagnostics (OBD) provisions based on the U.S. OBD II program;
  • Stringent evaporative and refueling emission-control requirements equivalent to the U.S. Tier 2 requirement with a streamlined test procedure;
  • Introduction of a low-temperature testing requirement and emission limits for CO, THC, and NOx for both gasoline and diesel vehicles; and
  • A multi-component compliance program involving agency- and manufacturer-run emission tests during pre-production, production, and in-use stages, and China’s first emission warranty and defect reporting program.

This policy update provides further details about some of these features, a comparison with emission regulations in other major markets, and a summary of the impact of this rule.