China: Heavy-duty: Emissions

China: Heavy-duty: Emissions


In 2018, China finalized China VI standards that will apply to new heavy-duty diesel vehicles nationwide in two stages. The first stage, China VI-a, is largely equivalent to Euro VI and applied to gas engines in July 2019, urban HDVs in July 2020, and all new HDVs in July 2021. The second stage, China VI-b, adds requirements such as anti-tampering monitoring and remote on-board diagnostics data reporting that are expected to enhance real-world emissions compliance. China VI-b will apply to gas engines nationwide starting in January 2021 and all new HDVs in July 2023.

Standard type
Conventional pollutant emission limits

Regulating Body

Nationwide: Ministry of Ecology and Environment
Regional and Local: Environmental Protection Bureaus

Current Standard

China VI: GB 17691-2018

Heavy-duty vehicles over 3,500 kg, equipped with compression ignition engines or positive ignition natural gas (NG) or liquefied petroleum gas (LPG) engines.


Emission standards for new heavy-duty truck and bus engines in China follow the European precedent, known as China I, II, III, etc. China has historically implemented equivalent Euro emission standards approximately 7-8 years after Europe.

Vehicle emission standards are developed by the Ministry of Ecology and Environment (MEE), then jointly issued by MEE and the State Administration for Market Regulation (SAMR).

The following table presents implementation dates for emission standards for heavy-duty diesel and gasoline vehicles in China.

Nationwide Emission Standards for Heavy-Duty Diesel and Gasoline Vehicles
Stage Standard Implementation Date
(type approval)
Implementation Date
(all sales and registrations)
Diesel Engines
China I GB 17691-2001 1 Sep 2000 1 Sep 2001
China II 1 Sep 2003 1 Sep 2004
China III GB 17691-2005 1 Jan 2007 1 Jan 2008a
China IV 1 Jul 2010b 1 Jul 2013c
China V 1 Jan 2016d
1 Jul 2016
1 Jan 2017d
1 Jul 2017
China IV-a GB 17691-2018 N.A. 1 Jul 2019e
1 Jul 2020d
1 Jul 2021
China VI-b N.A. 1 Jan 2021e
1 Jul 2023
Gasoline Engines
China I GB 14762-2002 1 Mar 2003 1 Jul 2003
China II 1 Sep 2003 1 Sep 2004
China III GB 14762-2008 1 Jul 2009 1 Jul 2010
China IV 1 Jul 2012 1 Jul 2013
a Existing stock permitted to be sold until 30 Jun 2008.
b In December 2011, MEP announced that China III type approvals would be permitted again until 30 Jun 2013.
c This date represents a 30-month delay from the original intended implementation date of 1 Jan 2011. The date was first extended by one year in December 2010, then again by an additional 18 months in December 2011.
d For public bus, sanitation and postal trucks, and other civil vehicle fleets.
e For gas-fueled HDVs.

Sub-national regions and cities in China are permitted to implement vehicle emission standards in advance of the nationwide implementation dates, under two conditions. First, the standard must have already been adopted and issued by the national government. Second, China’s State Council, the highest executive body, must grant approval. Beijing has historically led in the advanced implementation of vehicle emission standards, followed by Shanghai, Guangzhou, and some other major cities. The following table summarizes the advanced implementation of HDV emission standards in sub-national regions of China:

Advanced Implementation of Heavy-Duty Emission Standards in Sub-National Regions
Stage Beijing Shanghai Guangzhou and others
China I 1 Jan 1999 1 Jul 1999 n/a
China II 1 Jan 2003 1 Mar 2003 1 Jul 2005
China III 31 Dec 2005 HDV: phased-in over 2007 1 Sep 2006
China IV 1 Jul 2008 1 Nov 2009 1 June 2010 (GZ + 9 cities in Guangdong Province)
China V 1 Feb 2013
1 Jun 2015 for new HDV salesa
1 May 2014 31 Dec 2015 (GZ + 9 cities in Guangdong Province)
30 June 2016 Guangdong Province
1 Apr 2016 in 11 eastern provincesb for public bus, sanitation and postal trucks, and other civil vehicle fleets
China VI 1 Jan 2020 (China VI-b) n/a n/a
a Starting from 1 Jan 2016, DPFs will also be required on new sales of public HDVs (buses, sanitation, postal, tour coaches, shuttles etc)
b These 11 eastern provinces are Beijing, Tianjin, Hebei, Liaoning, Shanghai, Jiangsu, Zhejiang, Fujian, Shandong, Guangdong and Hainan.

Supplemental Testing Requirement

In January 2014, MEP issued a supplemental standard requiring China IV and V diesel engines for urban buses and service vehicles to be tested over the World Harmonized Transient Cycle. The supplemental standard is intended to prevent excess NOX emissions from China IV and V-certified vehicles.

In 2013, the Beijing EPB released two new supplemental standards (DB11/964-2013 and DB11/965-2013) for China IV and V heavy-duty vehicles to prevent excess urban NOx emissions. DB11/965-2013 was updated in 2017.

In 2017, MEE issued a supplemental standard for HDVs under China V to address the excess NOX emissions problem. The regulation is supplemental to all existing requirements under the China V standard, and requires additional on-road portable emission measurement system (PEMS) testing for new and in-use China V HDVs.

Technical Standards

Key improvements of the China VI HDV emission standard are:

  • Reductions in nitrogen oxide (NOX) and particulate matter (PM) emission limits by around 70% from the China V standard;
  • The introduction of particulate number (PN) limits;
  • A shift from the European Steady-state Cycle (ESC) and European Transient Cycle (ETC) to the more representative and dynamic World Harmonized Stationary Cycle (WHSC) and World Harmonized Transient Cycle (WHTC);
  • Inclusion of new World Harmonized Not-to-Exceed (WNTE) test;
  • Extended durability requirements;
  • Adoption of full vehicle Portable Emission Measurement System (PEMS) testing and requirements based on the European PEMS regulation, with modifications that address China-specific driving conditions for type tests, new production and in-service conformity testing;
  • Improved on-board diagnostic (OBD) system and anti-tampering provisions based on U.S. OBD requirements;
  • A requirement for vehicles to be equipped with a remote emission monitoring on-board terminal (remote OBD), the first regulation of its kind worldwide;
  • A multi-component compliance program involving agency- and manufacturer-run emission tests during pre-production, production, and in-use stages;
  • China’s first emission warranty program for HDVs, in which manufacturers are required to guarantee emission control components for a minimum distance travelled or service time.
  • The final rule indicates that future possible requirements on CO2 emissions from HDVs may be implemented.

Limit Values

Emission limits for China III-VI are shown below.

Emission Standards for Heavy-Duty Engines
Standard Test Cycle CO HC NMHC CH4a NOx PM Smoke PN
g/kWh 1/m #/kWh
China III ESC+ELR 2.1 0.66 5.0 0.10/0.13b 0.8
ETC 5.45 0.78 1.6 5.0 0.16/0.21a
China IV ESC+ELR 1.5 0.46 3.5 0.02 0.5
ETC 4.0 0.55 1.1 3.5 0.03
China V ESC+ELR 1.5 0.46 2.0 0.02 0.5
ETC 4.0 0.55 1.1 2.0 0.03
China VI WHSC (compression ignition engine) 1.5 0.13 0.4 0.1 8*1011
WHTC (compression ignition engine) 4.0 0.16 0.46 0.1 6*1011
WHTC (spark ignition engine) 4.0 0.16 0.5 0.46 0.1 6*1011
a Natural gas engines only  
b For engines with a per cylinder displacement of 3000 rpm  
Note: At the China I/II stage (not shown in this table), the test cycle was ECE R-49, or the Chinese 9-mode.  

NH3 slip limits began to be enforced under China V, when the NH3 slip limit was 25 ppm (peak) and 10 ppm (cycle average). For China VI, the NH3 slip limit is 10 ppm (cycle average). In addition to the more realistic test cycles and stringent emission limits, the China VI standard also introduces additional off-cycle test requirements, including the World Harmonized Not-to-Exceed (WNTE) test and a full-vehicle PEMS test. The test requirements and emission limits of the WNTE test in China VI are equivalent to the Euro VI standard.

Emission limits for WNTE test in China VI
Test CO (mg/kWh) THC (mg/kWh) NOX (mg/kWh) PM (mg/kWh)
WNTE 2000 220 600 16

PEMS Testing Requirements

China VI introduced PEMS testing for type tests, new production tests, and in-service conformity tests. The China VI PEMS testing requirements and emission limits primarily follow the Euro VI PEMS standard, with a few enhancements and modifications for the Chinese context. For data evaluation, the work-based window method is applied. A vehicle is considered adequate only if 90% or more valid windows meet emission limits. The provision also includes an innovative transient NOx concentration limit of 500 ppm, and requires that at least 95% of data points obtained from the PEMS testing not exceed this limit.

PEMS testing requirements
Vehicle category Useful lifea
Distance traveled (km) Service time (years)
M1, N1, M2 200,000 5
N2, N3 (GVW≤18 ton)
M3 Class I, Class II, Class A
M3 Class B (GVW≤7.5 ton)
300,000 6
N3 (GVW>18 tons)
M3 Class III
M3 Class B (GVW>7.5 tons)
700,000 7
a Distance traveled or service time, whichever is sooner
China PEMS emission limits for diesel
0.69 g/kWh
No limit for China VI-a
1.2×1012/kWh for China VI-b (CF=2.0)
6 g/kWh

Durability requirements and emission warranties

A vehicle’s useful life in the China VI HDV standard is identical to that of Euro VI. Improved from China V, longer distance durability is now required for all vehicle categories, while service time requirements remain the same.

Starting with China VI, manufacturers are required to guarantee a number of emissions-control components in their new vehicles for a minimum distance or time. If the emissions control equipment and/or related components malfunction during the warranty period, the manufacturer is responsible for repair.

Emission Durability Requirements
Vehicle Category Minimum warranty perioda
Distance Traveled (km) Service time (years)
M1, M2, N1 80,000 5
M3, N2, N3 160,000 5
a Distance traveled or service time, whichever is sooner

Compliance program

The China VI regulation also requires a number of agency- and manufacturer-run regulatory tests that apply to vehicle prototypes and throughout a vehicle’s useful life.

China VI compliance program

Source: China’s Stage VI emission standard for heavy-duty vehicles, ICCT.

Manufacturer-performed tests mandated by the China VI standards include four stages of testing: type test, conformity of production test, new vehicle test, and in-use conformity test. For all four manufacturer-run tests, the regulatory agency has the authority to conduct verification tests. For non-compliant vehicles, the manufacturer is required to submit a corrective action plan to the agency and subsequently implement the action plan after approval.

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