40 C.F.R. § 1039.510
Which duty cycles do I use for transient testing?
Cite as 40 C.F.R. § 1039.510 (2026)
(a) Measure emissions by testing the engine on a dynamometer with one of the following transient duty cycles to determine whether it meets the transient emission standards in § 1039.101(a): (1) For variable-speed engines, use the transient duty cycle described in appendix VI of this part. (2) [Reserved] (b) The transient test sequence consists of an initial run through the transient duty cycle from a cold start, 20 minutes with no engine operation, then a final run through the same transient duty cycle. Calculate the official transient emission result from the following equation: [69 FR 39213, June 29, 2004, as amended at 70 FR 40463, July 13, 2005; 75 FR 22991, Apr. 30, 2010; 76 FR 57437, Sept. 15, 2011; 79 FR 23751, Apr. 28, 2014]
- Cross-references to the CFR
- 1039.101