Regulatory Background

Nonroad engine emission standards have been the responsibility of two ministries: MOE and MLIT. Nonroad engine regulations adopted by these agencies replaced off-road emission standards by the former MOT and MOC ministries.

The emission standards apply to engines, rated between 19-560 kW, used in two types of vehicles:

  1. Special Motor Vehicles—self-propelled nonroad vehicles and machinery that are registered for operation on public roads (fitted with license plates).
  2. Nonroad Motor Vehicles—self-propelled and non-registered nonroad vehicles and machinery.

The emission limits for the two vehicle categories are the same, but they are introduced by separate regulatory acts. Some of the important regulatory steps include:

  • Regulations based on 2003 report of CEC (Central Environment Council): On June 28, 2005, the MOE promulgated a new set of standards for Special Vehicles, superseding former MOT standards. On March 28, 2006, the same standards were promulgated for Nonroad Vehicles, superseding former MOC standards. The regulations introduced emission limits based on the US EPA Tier 3 standards effective from 2006-2008.
  • Regulations based on 2008 report of CEC: In 2008, the CEC recommended further tightening of nonroad emission regulations:
    1. Emission standards based on US Tier 4i/EU Stage IIIB regulations, effective from 2011-2013. These regulations were promulgated in March 2010.
    2. Emission standards based on US Tier 4/EU Stage IV regulations, effective from 2015-2016.

In addition, voluntary emission standards exist for portable and transportable equipment (which is not regulated under the special/nonroad vehicle standards) that provides recognition of low emission engines for designation of low emission construction machinery.

Special/Nonroad Motor Vehicles

Diesel Engines: 2006-2008

The standards are summarized in Table 1. These standards are similar in stringency to the US Tier 3 (2006-2008) and the EU Stage III A (2005-2007) regulations. They do not require the use of exhaust aftertreatment devices, such as diesel particulate filters or NOx reduction catalysts.

Emissions are measured according to JIS B 8001-1 (Japanese version of ISO 8178) 8-mode test. Smoke is measured according to JCMAS T-004.

Table 1
Emission Standards for Diesel Special/Nonroad Vehicles: 2006-2008, g/kWh
Power (P) CO HC NOx PM Smoke Date
kW g/kWh % New Models All Models†
19 ≤ P < 37 5.0 1.0 6.0 0.4 40 2007.10 2008.09
37 ≤ P < 56 5.0 0.7 4.0 0.3 35 2008.10 2009.09
56 ≤ P < 75 5.0 0.7 4.0 0.25 30 2008.10 2010.09
75 ≤ P < 130 5.0 0.4 3.6 0.2 25 2007.10 2008.09
130 ≤ P < 560 3.5 0.4 3.6 0.17 25 2006.10 2008.09
† Applies to continuously produced nonroad vehicles (but not special vehicles) and imported special/nonroad vehicles.

Diesel Engines: 2011-2016

The standards, based on the US Tier 4i / EU Stage IIIB are shown in Table 2. The table also includes the Tier 4 / Stage IV based limits that have not yet been promulgated.

The limits for hydrocarbons were changed to non-methane hydrocarbons and the NRTC transient testing is required in addition to the steady-state 8-mode test.

Table 2
Emission Standards for Diesel Special/Nonroad Vehicles: 2011-2016, g/kWh
Power (P) CO NMHC NOx PM Smoke Date
kW g/kWh % New Models All Models
19 ≤ P < 37 5.0 0.7 4.0 0.03 25 2013.10 2015.09
37 ≤ P < 56 5.0 0.7 4.0 0.025 25 2013.10 2014.11
56 ≤ P < 75 5.0 0.19 3.3 0.02 25 2012.10 2014.04
5.0 0.19 0.4 0.02 25 2016* -
75 ≤ P < 130 5.0 0.19 3.3 0.02 25 2012.10 2013.11
5.0 0.19 0.4 0.02 25 2016* -
130 ≤ P < 560 3.5 0.19 2.0 0.02 25 2011.10 2013.04
3.5 0.19 0.4 0.02 25 2015* -
* Proposed.

Spark-Ignited Engines

The standards for spark ignited engines are summarized in Table 3. Emissions are measured according to JIS B 8001-1 (ISO 8178) 7-mode test.

Table 3
Emission Standards for Spark Ignited Special/Nonroad Vehicles, g/kWh
Power (P) 7-mode Idle Date
CO HC NOx CO HC New Models All Models†
kW g/kWh % ppm
19 ≤ P < 560 20.0 0.60 0.60 1 500 2007.10 2008.09
† Applies to continuously produced nonroad vehicles (but not special vehicles) and imported special/nonroad vehicles.

Portable/Transportable Equipment (Recognition System)

Under the recognition system regulations that became effective on March 17, 2006, manufacturers may apply for their engines to be recognized as a low emission engine for use in designated low emission construction machinery. The recognition system applies to portable and transportable (i.e., non-self-propelled) equipment, which is not emission regulated under the Special/Nonroad Motor Vehicle regulations.

The emission standards are listed in Table 4. Emissions are measured over the JIS B 8001-1 (ISO 8178) 8-mode test. For generator application, the rated speed is for 60 Hz and the intermediate speed is for 50 Hz.

Table 4
Emission Limits—Recognition System, g/kWh
Power (P) CO HC NOx PM Smoke
kW g/kWh %
8 ≤ P < 19 5.0 7.5* 0.4 40
19 ≤ P < 37 5.0 1.0 6.0 0.4 40
37 ≤ P < 56 5.0 0.7 4.0 0.3 35
56 ≤ P < 75 5.0 0.7 4.0 0.25 30
75 ≤ P < 130 5.0 0.4 3.6 0.2 25
130 ≤ P < 560 3.5 0.4 3.6 0.17 25
* NOx + HC

Useful Life

The useful life requirements (2005/2006 MOE regulations) for different engine categories and nonroad emission regulations are listed in Table 5.

Table 5
Useful Life Requirements
Type Power (kW) Useful Life Applicability
CI 8-19 3,000 h Recognition system
19-37 5,000 h Special vehicle
Nonroad vehicle
Recognition system
37-560 8,000 h
SI 19-560 5,000 h Special vehicle
Nonroad vehicle

The following requirements apply to deterioration factor testing:

  • Minimum test period is 1/3 of useful life
  • Loading requirements:
    • CI
      • 70% or more time above 60% of rated speed
      • 20% or more time above 90% of rated speed
      • Average loading factor shall be ≥ 40%
    • SI
      • 85% or more time above 60% of rated speed
      • 15% or more time above 90% of rated speed
      • Average loading factor shall be ≥ 30%
  • Equivalent procedures
    • CI: 40 CFR 89 or 1039, 97/68/EC
    • SI: 40 CFR 1048