--- kind: "section" citation: "40 C.F.R. § 1036.512" title: "40" number: "1036.512" heading: "Federal Test Procedure." url: "https://uscodex.org/cfr/40/1036.512" --- # §1036.512. Federal Test Procedure. - (a) Measure emissions using the transient Federal Test Procedure (FTP) as described in this section to determine whether engines meet the emission standards in [subpart B](/cfr/40/subpartB.md) of this part. Operate the engine or hybrid powertrain over one of the following transient duty cycles: - (1) For engines subject to spark-ignition standards, use the transient test interval described in [paragraph (b)](#b) of appendix B to this part. - (2) For engines subject to compression-ignition standards, use the transient test interval described in [paragraph (c)](#c) of appendix B to this part. - (b) **Procedures apply differently for testing certain kinds of engines and powertrains as follows—** - (1) The transient test intervals for nonhybrid engine testing are based on normalized speed and torque values. Denormalize speed as described in [40 CFR 1065.512](/cfr/40/1065.512.md). Denormalize torque as described in [40 CFR 1065.610(d)](/cfr/40/1065.610.md?p=d). - (2) Test hybrid powertrains as described in [§ 1036.510(b)(2)](/cfr/40/1036.510.md?p=b-2), with the following exceptions: - (i) Replace Pcontrated with Prated, which is the peak rated power determined in [§ 1036.520](/cfr/40/1036.520.md). - (ii) **Keep the transmission in drive for all idle segments after the initial idle segment.** - (iii) For hybrid engines, you may request to change the engine-commanded torque at idle to better represent curb idle transmission torque (CITT). - (iv) For plug-in hybrid powertrains, test over the FTP in both charge-sustaining and charge-depleting operation for criteria pollutant determination. - (c) Except as specified in [paragraph (d)](#d) of this section for plug-in hybrid powertrains, the FTP duty cycle consists of an initial run through the test interval from a cold start as described in [40 CFR part 1065](/cfr/40/part1065.md), [subpart F](/cfr/40/subpartF.md), followed by a (20 ±1) minute hot soak with no engine operation, and then a final hot start run through the same transient test interval. Engine starting is part of both the cold-start and hot-start test intervals. Calculate the total emission mass of each constituent, m, over each test interval as described in [40 CFR 1065.650](/cfr/40/1065.650.md). Calculate the total work, W, over the test interval as described in [40 CFR 1065.650(d)](/cfr/40/1065.650.md?p=d). For hybrid powertrains, calculate W using system power, Psys as described in [§ 1036.520(f)](/cfr/40/1036.520.md?p=f). Determine Psys using [§ 1036.520(f)](/cfr/40/1036.520.md?p=f). For powertrains with automatic transmissions, account for and include the work produced by the engine from the CITT load. Calculate the official transient emission result from the cold-start and hot-start test intervals using the following equation: - (d) **Determine criteria pollutant emissions for plug-in hybrid powertrains as follows—** - (1) **Carry out a charge-sustaining test as described in paragraph (b)(2) of this section.** - (2) **Carry out a charge-depleting test as described in paragraph (b)(2) of this section, except as follows—** - (i) **Fully charge the battery after preconditioning.** - (ii) Operate the engine or powertrain over one FTP duty cycle followed by alternating repeats of a 20-minute soak and a hot start test interval until you reach the end-of-test criteria defined in [40 CFR 1066.501(a)(3)](/cfr/40/1066.501.md?p=a-3). - (iii) **Calculate emission results for each successive pair of test intervals.** Calculate the emission result by treating the first of the two test intervals as a cold-start test. Figure 1 to [paragraph (d)(4)](#d-4) of this section provides an example of a charge-depleting test sequence where there are three test intervals with engine operation for two overlapping FTP duty cycles. - (3) Report the highest emission result for each criteria pollutant from all tests in paragraphs [(d)(1)](#d-1) and [(2)](#d-2) of this section, even if those individual results come from different test intervals. - (4) **The following figure illustrates an example of an FTP charge-depleting test sequence—** - (e) Determine CO2 emissions for plug-in hybrid engines and powertrains using the emissions results for all the transient duty cycle test intervals described in either paragraph [(b)](#b) or [(c)](#c) of appendix B to this part for both charge-depleting and charge-sustaining operation from [paragraph (d)(2)](#d-2) of this section. Calculate the utility factor weighted composite mass of emissions from the charge-depleting and charge-sustaining test results, eUF[emission]comp, as described in [§ 1036.510(e)](/cfr/40/1036.510.md?p=e), replacing occurrences of “SET” with “transient test interval”. Note this results in composite FTP CO2 emission results for plug-in hybrid engines and powertrains without the use of the cold-start and hot-start test interval weighting factors in Eq. 1036.512-1. - (f) Calculate and evaluate cycle-validation criteria as specified in [40 CFR 1065.514](/cfr/40/1065.514.md) for nonhybrid engines and [§ 1036.545](/cfr/40/1036.545.md) for hybrid powertrains. ## Notes ### Amendments [88 FR 4487, Jan. 24, 2023, as amended at 89 FR 29743, Apr. 22, 2024; 91 FR 7780, Feb. 18, 2026] ### Authority Authority: 42 U.S.C. 7401—7671q. ### Source Source: 88 FR 4487, Jan. 24, 2023, unless otherwise noted. ### Amendments [88 FR 4487, Jan. 24, 2023, as amended at 89 FR 29743, Apr. 22, 2024; 91 FR 7780, Feb. 18, 2026]