40 CFR § 86.164-08 - Supplemental Federal Test Procedure calculations.

§ 86.164-08 Supplemental Federal Test Procedure calculations.

(a) The provisions of § 86.144-94 (b) and (c) are applicable to this section except that the NOX humidity correction factor of § 86.144-94(c)(7)(iv) must be modified when adjusting SC03 environmental test cell NOX results to 100 grains of water according to paragraph (d) of this section. These provisions provide the procedures for calculating mass emission results of each regulated exhaust pollutant for the test schedules of FTP, US06, and SC03.

(b) The provisions of § 86.144-94(a) are applicable to this section. These provisions provide the procedures for determining the weighted mass emissions for the FTP test schedule (Ywm).

(c)

(1) When the test vehicle is equipped with air conditioning, the final reported test results for the SFTP composite (NMHC + NOX) and optional composite CO standards shall be computed by the following formulas.

(i) YWSFTP = 0.35(YFTP) + 0.37(YSC03) + 0.28(YUS06)

Where:

(A) YWSFTP = Mass emissions per mile for a particular pollutant weighted in terms of the contributions from the FTP, SC03, and US06 schedules. Values of YWSFTP are obtained for each of the exhaust emissions of NMHC, NOX and CO.

(B) YFTP = Weighted mass emissions per mile (YWM) based on the measured driving distance of the FTP test schedule.

(C) YSC03 = Calculated mass emissions per mile based on the measured driving distance of the SC03 test schedule.

(D)(1) YUS06 = Calculated mass emissions per mile based on the measured driving distance of the US06 test schedule; or,

(2) In the case of a 2-phase US06 test run according to the provisions of § 86.159-08(f)(2) and part 600 of this chapter:

YUS06 = Calculated mass emissions per mile, using the summed mass emissions of the “US06 City” phase and the “US06 Highway” phase, based on the measured driving distance of the US06 test schedule. The “US06 City” phase shall be sampled during seconds 0-130 and from 495 seconds until five seconds after the engine stops running (e.g. 602 or 603 seconds) of the US06 driving schedule. The “US06 Highway” phase shall be sampled during seconds 130-495 of the US06 driving schedule),

(ii) Composite (NMHC + NOX) = YWSFTP(NMHC) + YWSFTP(NOX)

Where:

(A) YWSFTP(NMHC) = results of paragraph (c)(1)(i) of this section for NMHC.

(B) YWSFTP(NOX) = results of paragraph (c)(1)(i) of this section for NOX.

(2) When the test vehicle is not equipped with air conditioning, the final reported test results for the SFTP composite (NMHC + NOX) and optional composite CO standards shall be computed by the following formulas.

(i) YWSFTP = 0.72(YFTP) + 0.28(YUS06)

Where:

(A) YWSFTP = Mass emissions per mile for a particular pollutant weighted in terms of the contributions from the FTP and US06 schedules. Values of YWSFTP are obtained for each of the exhaust emissions of NMHC, NOX and CO.

(B) YFTP = Weighted mass emissions per mile (Ywm) based on the measured driving distance of the FTP test schedule.

(C)(1) YUS06 = Calculated mass emissions per mile based on the measured driving distance of the US06 test schedule; or,

(2) In the case of a 2-phase US06 test run according to the provisions of § 86.159-08(f)(2) and part 600 of this chapter:

YUS06 = Calculated mass emissions per mile, using the summed mass emissions of the “US06 City” phase and the “US06 Highway” phase, based on the measured driving distance of the US06 test schedule. The “US06 City” phase shall be sampled during seconds 0-130 and from 495 seconds until five seconds after the engine stops running (e.g. 602 or 603 seconds) of the US06 driving schedule. The “US06 Highway” phase shall be sampled during seconds 130-495 of the US06 driving schedule),

(ii) Composite (NMHC + NOX) = YWSFTP(NMHC) + YWSFTP(NOX)

Where:

(A) YWSFTP(NMHC) = results of paragraph (c)(2)(i) of this section for NMHC.

(B) YWSFTP(NOX) = results of paragraph (c)(2)(i) of this section for NOX.

(d) The NOX humidity correction factor for adjusting NOX test results to the environmental test cell air conditioning ambient condition of 100 grains of water/pound of dry air is:

KH (100) = 0.8825/[1-0.0047(H-75)]
Where:
H = measured test humidity in grains of water/pound of dry air.
[71 FR 77922, Dec. 27, 2006, as amended at 74 FR 61548, Nov. 25, 2009]