{"data":{"id":"us/40-cfr-appendix-ii-to-part-1042","jurisdiction":"us","citation":"40 CFR Appendix II to Part 1042","heading":"Appendix II to Part 1042— Steady-State Duty Cycles","body":"(a) The following duty cycles apply as specified in § 1042.505(b)(1):\n(1) The following duty cycle applies for discrete-mode testing:\nE3 mode No. Engine speed 1 Percent of maximum test power Weighting factors\n1 Maximum test speed 100 0.2\n2 91% 75 0.5\n3 80% 50 0.15\n4 63% 25 0.15\n1 Maximum test speed is defined in 40 CFR part 1065. Percent speed values are relative to maximum test speed.\n(2) The following duty cycle applies for ramped-modal testing:\nRMC mode Time in mode (seconds) Engine speed 1 3 Power (percent) 2 3\n1a Steady-state 229 Maximum test speed 100%.\n1b Transition 20 Linear transition Linear transition in torque.\n2a Steady-state 166 63% 25%.\n2b Transition 20 Linear transition Linear transition in torque.\n3a Steady-state 570 91% 75%.\n3b Transition 20 Linear transition Linear transition in torque.\n4a Steady-state 175 80% 50%.\n1 Maximum test speed is defined in 40 CFR part 1065. Percent speed is relative to maximum test speed.\n2 The percent power is relative to the maximum test power.\n3 Advance from one mode to the next within a 20 second transition phase. During the transition phase, command a linear progression from the torque setting of the current mode to the torque setting of the next mode, and simultaneously command a similar linear progression for engine speed if there is a change in speed setting.\n(b) The following duty cycles apply as specified in § 1042.505(b)(2):\n(1) The following duty cycle applies for discrete-mode testing:\nE5 mode No. Engine speed 1 Percent of maximum test power Weighting factors\n1 Maximum test speed 100 0.08\n2 91% 75 0.13\n3 80% 50 0.17\n4 63% 25 0.32\n5 Warm idle 0 0.3\n1 Maximum test speed is defined in 40 CFR part 1065. Percent speed values are relative to maximum test speed.\n(2) The following duty cycle applies for ramped-modal testing:\nRMC mode Time in mode (seconds) Engine speed 1 3 Power (percent) 2 3\n1a Steady-state 167 Warm idle 0.\n1b Transition 20 Linear transition Linear transition in torque.\n2a Steady-state 85 Maximum test speed 100%.\n2b Transition 20 Linear transition Linear transition in torque.\n3a Steady-state 354 63% 25%.\n3b Transition 20 Linear transition Linear transition in torque.\n4a Steady-state 141 91% 75%.\n4b Transition 20 Linear transition Linear transition in torque.\n5a Steady-state 182 80% 50%.\n5b Transition 20 Linear transition Linear transition in torque.\n6 Steady-state 171 Warm idle 0.\n1 Maximum test speed is defined in 40 CFR part 1065. Percent speed is relative to maximum test speed.\n2 The percent power is relative to the maximum test power.\n3 Advance from one mode to the next within a 20 second transition phase. During the transition phase, command a linear progression from the torque setting of the current mode to the torque setting of the next mode, and simultaneously command a similar linear progression for engine speed if there is a change in speed setting.\n(c) The following duty cycles apply as specified in § 1042.505(b)(3):\n(1) The following duty cycle applies for discrete-mode testing:\nE2 mode No. Engine speed 1 Torque (percent) 2 Weighting factors\n1 Engine Governed 100 0.2\n2 Engine Governed 75 0.5\n3 Engine Governed 50 0.15\n4 Engine Governed 25 0.15\n1 Speed terms are defined in 40 CFR part 1065.\n2 The percent torque is relative to the maximum test torque as defined in 40 CFR part 1065.\n(2) The following duty cycle applies for ramped-modal testing:\nRMC mode Time in mode (seconds) Engine speed Torque (percent)1 2\n1a Steady-state 229 Engine Governed 100%.\n1b Transition 20 Engine Governed Linear transition.\n2a Steady-state 166 Engine Governed 25%.\n2b Transition 20 Engine Governed Linear transition.\n3a Steady-state 570 Engine Governed 75%.\n3b Transition 20 Engine Governed Linear transition.\n4a Steady-state 175 Engine Governed 50%.\n1 The percent torque is relative to the maximum test torque as defined in 40 CFR part 1065.\n2 Advance from one mode to the next within a 20 second transition phase. During the transition phase, command a linear progression from the torque setting of the current mode to the torque setting of the next mode.","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":"b16e83c24c8211ff3de72fe1052018bf3f4eb55aba9ab9b33332ce34879b5d9b","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-appendix-i-to-part-1042","next":"us/40-cfr-appendix-iii-to-part-1042"},"notice":"GroundRules: Original legal text. Not legal advice."}