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 year NO X HC NO X + NMHC CO PM kW< 8 2000 10.5 8.0 1.0 8 ≤ kW < 19 2000 9.5 6.6 0.80 19 ≤ kW < 37 1999 9.5 5.5 0.80 37 ≤ kW < 75 1998 9.2 75 ≤ kW < 130 1997 9.2 130 ≤ kW ≤ 560 1996 9.2 1.3 11.4 0.54 kW > 560 2000 9.2 1.3 11.4 0.54 (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 year NO X + NMHC CO PM kW< 8 2005 7.5 8.0 0.80 8 ≤ kW < 19 2005 7.5 6.6 0.80 19 ≤ kW < 37 2004 7.5 5.5 0.60 37 ≤ kW < 75 2004 7.5 5.0 0.40 75 ≤ kW < 130 2003 6.6 5.0 0.30 130 ≤ kW < 225 2003 6.6 3.5 0.20 225 ≤ kW < 450 2001 6.4 3.5 0.20 450 ≤ kW ≤ 560 2002 6.4 3.5 0.20 kW > 560 2006 6.4 3.5 0.20 (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 NO X +NMHC CO PM 37 ≤ kW < 75 2008 4.7 5.0 0.40 75 ≤ kW < 130 2007 4.0 5.0 0.30 130 ≤ kW ≤ 560 2006 4.0 3.5 0.20 (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]