China: Heavy-Duty Engines

Implementation Schedule

With a few exceptions, emission standards for new onroad heavy-duty vehicles (HGV) and engines are based on the European standards. Implementation dates for the emission standards are listed in Table 1. China VI-a and China VI-b standards include the same emission limits, but China VI-b includes some more stringent in-use (PEMS) testing and monitoring requirements [3925][3926].

China III-V Emission Standards

Emission Limits

The legislation for China III-V stages—which were based on Euro III-V, respectively—was adopted in 2005 [2881]. The emission limits are shown in Table 2.

At the China I/II stage (not shown in the table), the test was ECE R-49 or the Chinese 9-mode.

Supplemental China IV-V Requirements

Supplemental requirements were adopted to prevent excess NOx emissions during low-speed, urban driving conditions from some HDVs type approved to China IV and China V standards. These requirements included:

• World Harmonized Transient Cycle (WHTC) limits—applicable in Beijing and nationally, and
• PEMS testing requirements—first applicable in Beijing, then nationally.

The Beijing Municipal Environmental Protection Bureau (EPB) released two local standards in February 2013 and the Ministry of Environmental Protection adopted a national standard in January 2014. These standards are supplemental to China IV and V standards and apply to China IV and V vehicles with GVW > 3,500 kg, registered in Beijing and nationally, respectively.

WHTC Limits. One of the Beijing standards [2895] implemented March 1, 2013 and the national standard [2897][3400] implemented January 1, 2015, required China IV and V engines to be tested over the WHTC in addition to the ETC (in Europe, testing over the WHTC was not required until the Euro VI stage). The Beijing standards applied to diesel and gas fueled engines while the national standards applied to only diesel fueled engines. Both cold-start and hot-start tests were required, with results weighted 14% and 86%, respectively. Table 3 and Table 4 provide the WHTC cycle limits for the China IV and V stages. Most of the limit values are equal to the Euro IV/V ETC values except those for NOx emissions.

PEMS Testing. The second Beijing standard [2896], implemented July 1, 2013, established in-use, complete vehicle Portable Emission Measurement System (PEMS) testing requirements for manufacturers to prove that real-world emissions do not overly exceed the type approval limit values. From October 1, 2017, PEMS testing requirements became effective nationally, applicable to new type approvals of China V heavy-duty diesel and gas powered models [3971].

China VI Emission Standards

The first proposal for Euro VI-based emission standards was published in 2015 by the City of Beijing [3292][3293]. These Beijing VI emission standards were never finalized and have been replaced with the national China VI program. The final China VI emission standards were published in 2018, with a phase-in schedule from 2019.07 through 2023.07 (Table 1) [3925][3926]. The emission limits are shown in Table 5.

The China VI regulation includes a multi-component compliance program involving agency- and manufacturer-run emission tests during pre-production, production, and in-use stages. It also includes full vehicle PEMS testing requirements based on the European PEMS regulations.

The China VI standards include two phases, China VI-a and China VI-b. China VI-a is largely equivalent to the Euro VI standard. China VI-b introduces more stringent testing requirements (including a PN limit of 1.2×10¹² kWh^-1 for full-vehicle PEMS tests) and a remote emission monitoring system.

Emission Durability

Emission durability requirements, including the engine useful life and the minimum aftertreatment testing periods, are shown in Table 6. The aftertreatment periods according to HJ 438-2008 are mandatory for type approval and production conformity, while GB 20890-2007 provides a guideline to conduct aftertreatment durability testing during product development.

The GB 20890-2007 standard recommends that aftertreatment testing be conducted on-vehicle, over the China Heavy-Duty Durability Cycle—Vehicle (C-HDD-V). Alternatively, an engine based durability test can be conducted over the China Heavy-Duty Durability Cycle—Engine (C-HDD-E).

Emission Warranty. China VI regulations introduced the first mandatory emission warranty program for HDVs. The China VI minimum emission warranty periods are 80,000 km/5 years for vehicle categories M1, M2 and N1; and 160,000 km/5 years for categories M3, N2, and N3.

OBD Requirements

China VI regulations include OBD requirements that are based on the Euro VI OBD program. An OBD system must be installed on all China VI engines and vehicles to identify, record and communicate types of malfunctions. The OBD threshold limits are listed in Table 7. If emissions exceed an OBD threshold over a certain amount of time, a permanent code must be stored in the computer. An operator inducement system is also required that, when activated, reduces the vehicle torque and/or limits the maximum speed [3926].

Remote OBD. China VI-b standards require HDVs to be equipped with an on-board remote emissions monitoring system. Real-time engine data from the ECU, NOx sensor, DPF and other emission-related data are required to be reported remotely to the monitoring center of the regulatory agency.

In 2020.04, draft technical requirements for remote emission monitoring applicable to all China V and China VI vehicles were released [4915]. For in-use vehicles, retrofits would be required. Effective mid-2020, a number of municipalities used various mechanisms ranging from outright requirements to subsidies and waiving of annual emission inspections to encourage vehicles as old as China IV to adopt remote OBD systems.