This section describes how to test engines under steady-state conditions.
(a) Measure emissions by testing the engine on a dynamometer with the following ramped-modal duty cycle to determine whether it meets the applicable steady-state emission standards:
| RMC mode |
Time in mode (seconds) |
Engine speed12 | Torque (percent)2 3 |
CO2 weighting (percent)4 |
|---|---|---|---|---|
| 1a Steady-state | 170 | Warm Idle | 0 | 6 |
| 1b Transition | 20 | Linear Transition | Linear Transition | |
| 2a Steady-state | 173 | A | 100 | 9 |
| 2b Transition | 20 | Linear Transition | Linear Transition | |
| 3a Steady-state | 219 | B | 50 | 10 |
| 3b Transition | 20 | B | Linear Transition | |
| 4a Steady-state | 217 | B | 75 | 10 |
| 4b Transition | 20 | Linear Transition | Linear Transition | |
| 5a Steady-state | 103 | A | 50 | 12 |
| 5b Transition | 20 | A | Linear Transition | |
| 6a Steady-state | 100 | A | 75 | 12 |
| 6b Transition | 20 | A | Linear Transition | |
| 7a Steady-state | 103 | A | 25 | 12 |
| 7b Transition | 20 | Linear Transition | Linear Transition | |
| 8a Steady-state | 194 | B | 100 | 9 |
| 8b Transition | 20 | B | Linear Transition | |
| 9a Steady-state | 218 | B | 25 | 9 |
| 9b Transition | 20 | Linear Transition | Linear Transition | |
| 10a Steady-state | 171 | C | 100 | 2 |
| 10b Transition | 20 | C | Linear Transition | |
| 11a Steady-state | 102 | C | 25 | 1 |
| 11b Transition | 20 | C | Linear Transition | |
| 12a Steady-state | 100 | C | 75 | 1 |
| 12b Transition | 20 | C | Linear Transition | |
| 13a Steady-state | 102 | C | 50 | 1 |
| 13b Transition | 20 | Linear Transition | Linear Transition | |
| 14 Steady-state | 168 | Warm Idle | 0 | 6 |
1Speed terms are defined in 40 CFR part 1065.
2Advance from one mode to the next within a 20-second transition phase. During the transition phase, command a linear progression from the speed or torque setting of the current mode to the speed or torque setting of the next mode.
3The percent torque is relative to maximum torque at the commanded engine speed.
4Use the specified weighting factors to calculate composite emission results for CO2 as specified in 40 CFR 1036.501.
(b) Perform the ramped-modal test as described in 40 CFR part 1065.
(c) For 2007 through 2010 model years, manufacturers may follow the mode order described in this paragraph (c) instead of the mode order specified in paragraph (a) of this section. Any EPA testing with these engines will rely on the same procedure used by the manufacturer for certification.
| RMC Mode | Time in mode (seconds) |
Engine speed12 | Torque (percent)23 |
|---|---|---|---|
| 1a Steady-state | 170 | Warm Idle | 0. |
| 1b Transition | 20 | Linear Transition | Linear Transition. |
| 2a Steady-state | 170 | A | 100. |
| 2b Transition | 20 | A | Linear Transition. |
| 3a Steady-state | 102 | A | 25. |
| 3b Transition | 20 | A | Linear Transition. |
| 4a Steady-state | 100 | A | 75. |
| 4b Transition | 20 | A | Linear Transition. |
| 5a Steady-state | 103 | A | 50. |
| 5b Transition | 20 | Linear Transition | Linear Transition. |
| 6a Steady-state | 194 | B | 100. |
| 6b Transition | 20 | B | Linear Transition. |
| 7a Steady-state | 219 | B | 25. |
| 7b Transition | 20 | B | Linear Transition. |
| 8a Steady-state | 220 | B | 75. |
| 8b Transition | 20 | B | Linear Transition. |
| 9a Steady-state | 219 | B | 50. |
| 9b Transition | 20 | Linear Transition | Linear Transition. |
| 10a Steady-state | 171 | C | 100. |
| 10b Transition | 20 | C | Linear Transition. |
| 11a Steady-state | 102 | C | 25. |
| 11b Transition | 20 | C | Linear Transition. |
| 12a Steady-state | 100 | C | 75. |
| 12b Transition | 20 | C | Linear Transition. |
| 13a Steady-state | 102 | C | 50. |
| 13b Transition | 20 | Linear Transition | Linear Transition. |
| 14 Steady-state | 168 | Warm Idle | 0. |
1Speed terms are defined in 40 CFR part 1065.
2Advance from one mode to the next within a 20-second transition phase. During the transition phase, command a linear progression from the speed or torque setting of the current mode to the speed or torque setting of the next mode.
3The percent torque is relative to maximum torque at the commanded engine speed.
[79 FR 23704, Apr. 28, 2014, as amended at 81 FR 73981, Oct. 25, 2016]
Tried the LawStack mobile app?
Join thousands and try LawStack mobile for FREE today.
- Carry the law offline, wherever you go.
- Download CFR, USC, rules, and state law to your mobile device.
