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Appendix I to Part 1039—Summary of Previous Emission Standards

Summary of Previous Emission Standards

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Displayed edition2026-04-27
Last updated2026-04-27

Appendix I to Part 1039—Summary of Previous Emission Standards

The following standards, which EPA originally adopted under 40 CFR part 89, apply to nonroad compression-ignition engines produced before the model years specified in § 1039.1:

(a) Tier 1 standards apply as summarized in the following table:

Table 1 to Appendix I—Tier 1 Emission Standards

[g/kW-hr]

Rated power (kW)Starting model yearNOXHCNOX + NMHCCOPM
kW< 8200010.58.01.0
8 ≤ kW < 1920009.56.60.80
19 ≤ kW < 3719999.55.50.80
37 ≤ kW < 7519989.2
75 ≤ kW < 13019979.2
130 ≤ kW ≤ 56019969.21.311.40.54
kW > 56020009.21.311.40.54

(b) Tier 2 standards apply as summarized in the following table:

Table 2 to Appendix I—Tier 2 Emission Standards

[g/kW-hr]

Rated power (kW)Starting model yearNOX + NMHCCOPM
kW< 820057.58.00.80
8 ≤ kW < 1920057.56.60.80
19 ≤ kW < 3720047.55.50.60
37 ≤ kW < 7520047.55.00.40
75 ≤ kW < 13020036.65.00.30
130 ≤ kW < 22520036.63.50.20
225 ≤ kW < 45020016.43.50.20
450 ≤ kW ≤ 56020026.43.50.20
kW > 56020066.43.50.20

(c) Tier 3 standards apply as summarized in the following table:

Table 3 to Appendix I—Tier 3 Emission Standards

[g/kW-hr]

Rated power

(kW)
Starting

model year
NOX+NMHCCOPM
37 ≤ kW < 7520084.75.00.40
75 ≤ kW < 13020074.05.00.30
130 ≤ kW ≤ 56020064.03.50.20

(d) Tier 1 through Tier 3 standards applied only for discrete-mode steady-state testing. There were no not-to-exceed standards or transient testing.

[86 FR 34507, June 29, 2021, as amended at 88 FR 4660, Jan. 24, 2023]