US: Heavy-duty: SET

US: Heavy-duty: SET

Overview

The heavy-duty Supplemental Emissions Test (SET) is a 13-mode steady-state engine dynamometer test cycle, introduced by the US EPA as part of the 1998 consent decreees with US heavy-duty engine manufacturers. In addition to Heavy-Duty FTP Transient Cycle testing, consent decree engines subject to US EPA 2004 emission standards and model year 2007 and later engines must also demonstrate compliance when tested over the SET test. There are several versions of this test, including two ramped mode cycles (RMC) and one discrete mode cycle (DMC).

Description

The discrete mode cycle SET is equivalent to the European Stationary Cycle (ESC). It was the test used for engine testing under the 1998 consent decrees.

The 2007 ramped mode cycle SET is applicable to 2007-2009 heavy-duty engines. While it contains the same operating modes and weightings as the discrete mode test, their order is different and the transition between modes is defined. For 2007-2009 model year engines, manufacturers could use either the 2007 ramped mode SET or the discrete mode SET.

For 2010 and later model year heavy-duty engines, manufacturers must use the 2010 ramped mode SET. It is similar to the 2007 ramped mode SET with the exception that the order in which the modes are run is the same as for the discrete mode SET and ESC cycles. For the 2010 model year only, manufacturers could continue to use the 2007 ramped mode SET as long as it did not adversely affect the ability to demonstrate compliance with emission standards.

The table below summarizes two ramped mode SET cycles. Speeds A, B and C are defined in the same way as for the ESC cycle.

 

Ramped Mode Cycle SET
RMC Mode 2007-2009 2010 & later
Time, s Speed Torque, % Time, s Speed Torque, %
1a Steady-state 170 Warm idle 0 170 Warm idle 0
1b Transition 20 Linear transition Linear transition 20 Linear transition Linear transition
2a Steady-state 170 A 100 173 A 100
2b Transition 20 A Linear transition 20 Linear transition Linear transition
3a Steady-state 102 A 25 219 B 50
3b Transition 20 A Linear transition 20 B Linear transition
4a Steady-state 100 A 75 217 B 75
4b Transition 20 A Linear transition 20 Linear transition Linear transition
5a Steady-state 103 A 50 103 A 50
5b Transition 20 Linear transition Linear transition 20 A Linear transition
6a Steady-state 194 B 100 100 A 75
6b Transition 20 B Linear transition 20 A Linear transition
7a Steady-state 219 B 25 103 A 25
7b Transition 20 B Linear transition 20 Linear transition Linear transition
8a Steady-state 220 B 75 194 B 100
8b Transition 20 B Linear transition 20 B Linear transition
9a Steady-state 219 B 50 218 B 25
9b Transition 20 Linear transition Linear transition 20 Linear transition Linear transition
10a Steady-state 171 C 100 171 C 100
10b Transition 20 C Linear transition 20 C Linear transition
11a Steady-state 102 C 25 102 C 25
11b Transition 20 C Linear transition 20 C Linear transition
12a Steady-state 100 C 75 100 C 75
12b Transition 20 C Linear transition 20 C Linear transition
13a Steady-state 102 C 50 102 C 50
13b Transition 20 Linear transition Linear transition 20 Linear transition Linear transition
14 Steady-state 168 Warm idle 0 168 Warm idle 0

 

Contact Us

Questions or updates about policies?