Korean emission standards for new mobile nonroad diesel engines are based on US regulations. Engines used in construction equipment have been regulated since 2004. Emissions from engines used in agricultural machinery are regulated since 2013.

  • First nonroad emission standards became effective in 2004/2005, based on US Tier 1/Tier 2 standards, respectively. There were no smoke opacity requirements. The Tier 1/2 standards applied to engines between 19 - 560 kW rated power, in such applications as excavators (>1 t), bulldozers, loaders (>2 t), cranes, graders, rollers, and forklift trucks.
  • Emission standards based on US Tier 3 requirements became effective in 2009 for construction machinery and in 2013 for agricultural equipment.
  • Tier 4-based standards are effective from 2015. These emission limits are based on Tier 4 final requirements—the US Tier 4 intermediate stage was skipped.

The emission standards are summarized in Table 1.

Table 1
Emission Standards for Nonroad Engines
DatePowerCOHCNOx+HCNOxPMReference
g/kWh
2004 19 ≤ kW < 37 5.5- 9.5- 0.8US Tier 1
37 ≤ kW < 75 5.51.3- 9.20.6
75 ≤ kW < 130 5.01.3- 9.20.6
130 ≤ kW < 2255.01.3- 9.20.54
225 ≤ kW < 5605.01.3- 9.20.54
2005 19 ≤ kW < 37 5.5-7.5-0.6US Tier 2
37 ≤ kW < 75 5.0-7.5-0.4
75 ≤ kW < 130 5.0-6.6-0.3
130 ≤ kW < 2253.5-6.6-0.2
225 ≤ kW < 5603.5-6.4-0.2
2009† 19 ≤ kW < 37 5.5-7.5-0.6US Tier 3
37 ≤ kW < 75 5.0-4.7-0.4
75 ≤ kW < 130 5.0-4.0-0.3
130 ≤ kW < 5603.5-4.0-0.2
2015 kW < 8 8.0-7.7-0.4US Tier 4
8 ≤ kW < 19 6.6-7.5-0.4
19 ≤ kW < 37 5.5-4.7-0.03
37 ≤ kW < 56 5.0-4.7-0.03
56 ≤ kW < 130 5.00.19-0.400.02
130 ≤ kW < 5603.50.19-0.400.02
† Aplicable to construction machinery; 2013 for agricultural equipment.

Emissions are measured over the ISO 8178 C1 test—also known as the NRSC or, in Korea, as KC1-8. Beginning with Tier 4 standards, compliance must be additionally demonstrated over the transient NRTC test.

Engines are emission certified by the Korean Ministry of Environment or the National Institute of Environmental Research.