{"data":{"id":"us/40-cfr-appendix-iii-to-part-1042","jurisdiction":"us","citation":"40 CFR Appendix III to Part 1042","heading":"Appendix III to Part 1042—Not-to-Exceed Zones","body":"(a) The following definitions apply for this Appendix III:\n(1) Percent power means the percentage of the maximum power achieved at Maximum Test Speed (or at Maximum Test Torque for constant-speed engines).\n(2) Percent speed means the percentage of Maximum Test Speed.\n(b) Figure 1 of this Appendix illustrates the default NTE zone for marine engines certified using the duty cycle specified in § 1042.505(b)(1), except for variable-speed propulsion marine engines used with controllable-pitch propellers or with electrically coupled propellers, as follows:\n(1) Subzone 1 is defined by the following boundaries:\n(i) Percent power ÷ 100 \u003e 0.7 · (percent speed ÷ 100) 2.5.\n(ii) Percent power ÷ 100 ≤ (percent speed ÷ 90) 3.5.\n(iii) Percent power ÷ 100 ≥ 3.0 · (1−percent speed ÷ 100).\n(2) Subzone 2 is defined by the following boundaries:\n(i) Percent power ÷ 100 ≥ 0.7 · (percent speed ÷ 100) 2.5.\n(ii) Percent power ÷ 100 ≤ (percent speed ÷ 90) 3.5.\n(iii) Percent power ÷ 100 \u003c 3.0 · (1−percent speed ÷ 100).\n(iv) Percent speed ÷ 100 ≥ 0.7.\n(3) Note that the line separating Subzone 1 and Subzone 2 includes the following endpoints:\n(i) Percent speed = 78.9 percent; Percent power = 63.2 percent.\n(ii) Percent speed = 84.6 percent; Percent power = 46.1 percent.\n(c) Figure 2 of this Appendix illustrates the default NTE zone for recreational marine engines certified using the duty cycle specified in § 1042.505(b)(2), except for variable-speed marine engines used with controllable-pitch propellers or with electrically coupled propellers, as follows:\n(1) Subzone 1 is defined by the following boundaries:\n(i) Percent power ÷ 100 ≥ 0.7 · (percent speed ÷ 100) 2.5.\n(ii) Percent power ÷ 100 ≤ (percent speed ÷ 90) 3.5.\n(iii) Percent power ÷ 100 ≥ 3.0 · (1−percent speed ÷ 100).\n(iv) Percent power ≤ 95 percent.\n(2) Subzone 2 is defined by the following boundaries:\n(i) Percent power ÷ 100 ≥ 0.7 · (percent speed ÷ 100) 2.5.\n(ii) Percent power ÷ 100 ≤ (percent speed ÷ 90) 3.5.\n(iii) Percent power ÷ 100 \u003c 3.0 · (1−percent speed ÷ 100).\n(iv) Percent speed ≥ 70 percent.\n(3) Subzone 3 is defined by the following boundaries:\n(i) Percent power ÷ 100 ≤ (percent speed ÷ 90) 3.5.\n(ii) Percent power \u003e 95 percent.\n(4) Note that the line separating Subzone 1 and Subzone 3 includes a point at Percent speed = 88.7 percent and Percent power = 95.0 percent. See paragraph (b)(3) of this appendix regarding the line separating Subzone 1 and Subzone 2.\n(d) Figure 3 of this Appendix illustrates the default NTE zone for variable-speed marine engines used with controllable-pitch propellers or with electrically coupled propellers that are certified using the duty cycle specified in § 1042.505(b)(1), (2), or (3), as follows:\n(1) Subzone 1 is defined by the following boundaries:\n(i) Percent power ÷ 100 ≥ 0.7 · (percent speed ÷ 100) 2.5.\n(ii) Percent power ÷ 100 ≥ 3.0 · (1−percent speed ÷ 100).\n(iii) Percent speed ≥ 78.9 percent.\n(2) Subzone 2a is defined by the following boundaries:\n(i) Percent power ÷ 100 ≥ 0.7 · (percent speed ÷ 100) 2.5.\n(ii) Percent speed ≥70 percent.\n(iii) Percent speed \u003c78.9 percent, for Percent power \u003e63.3 percent.\n(iv) Percent power ÷ 100 \u003c3.0 · (1−percent speed ÷ 100), for Percent speed ≥78.9 percent.\n(3) Subzone 2b is defined by the following boundaries:\n(i) The line formed by connecting the following two points on a plot of speed-vs.-power:\n(A) Percent speed = 70 percent; Percent power = 28.7 percent.\n(B) Percent power = 40 percent; Speed = governed speed.\n(ii) Percent power ÷ 100 \u003c 0.7 · (percent speed ÷ 100) 2.5.\n(4) Note that the line separating Subzone 1 and Subzone 2a includes the following endpoints:\n(i) Percent speed = 78.9 percent; Percent power = 63.3 percent.\n(ii) Percent speed = 84.6 percent; Percent power = 46.1 percent.\n(e) Figure 4 of this Appendix illustrates the default NTE zone for constant-speed engines certified using a duty cycle specified in § 1042.505(b)(3) or (4), as follows:\n(1) Subzone 1 is defined by the following boundaries:\n(i) Percent power ≥70 percent.\n(ii) [Reserved]\n(2) Subzone 2 is defined by the following boundaries:\n(i) Percent power \u003c70 percent.\n(ii) Percent power ≥40 percent.\n(f) Figure 5 of this Appendix illustrates the default NTE zone for variable-speed auxiliary marine engines certified using the duty cycle specified in § 1042.505(b)5)(ii) or (iii), as follows:\n(1) The default NTE zone is defined by the boundaries specified in 40 CFR 86.1370(b)(1), (2), and (4).\n(2) A special PM subzone is defined in 40 CFR 1039.515(b).","path":["Title 40—Protection of Environment","CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY","SUBCHAPTER U—AIR POLLUTION CONTROLS","PART 1042—CONTROL OF EMISSIONS FROM NEW AND IN-USE MARINE COMPRESSION-IGNITION ENGINES AND VESSELS"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-40.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:26:04Z","sha256":"ef86219959d1ae847d4ce692515304e6e7af317eda869ec30d1912916296d163","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-appendix-ii-to-part-1042","next":"us/40-cfr-1043.1"},"notice":"GroundRules: Original legal text. Not legal advice."}