For vehicles subject to an NMOG standard, determine NMOG as described in paragraph (a) of this section. Except as specified in the standard-setting part, you may alternatively calculate NMOG results based on measured NMHC emissions as described in paragraphs (c) through (f) of this section. Note that references to the FTP in this section apply for testing over the FTP test cycle at any ambient temperature.
Where:
mNMHC = the mass of NMHC and all oxygenated hydrocarbon (OHC) in the exhaust, as determined using Eq. 1066.605-2. Calculate NMHC mass based on [RHO]NMHC.
[RHO]NMHC = the effective C1-equivalent density of NMHC as specified in § 1066.1005(f) .
mOHCi = the mass of oxygenated species i in the exhaust calculated using Eq. 1066.605-2.
[RHO]OCHi = the C1-equivalent density of oxygenated species i.
RFOHCi[THC-FID] = the response factor of a THC-FID to oxygenated species i relative to propane on a C1-equivalent basis as determined in 40 CFR 1065.845 .
mNMHC = 0.0125 g
mCH3OH = 0.0002 g
mC2H5OH = 0.0009 g
mCH2O = 0.0001 g
mC2H4O = 0.00005 g
RFCH3OH[THC-FID] = 0.63
RFC2H5OH[THC-FID] = 0.75
RFCH2O[THC-FID] = 0.00
RFC2H4O[THC-FID] = 0.50
[RHO]NMHC-liq = 576.816 g/m3
[RHO]CH3OH = 1332.02 g/m3
[RHO]C2H5OH = 957.559 g/m3
[RHO]CH2O = 1248.21 g/m3
[RHO]C2H4O = 915.658 g/m3
Where:
eNMOGh = mass emission rate of NMOG from the hot-running test cycle.
eNMHCh = mass emission rate of NMHC from the hot-running test cycle, calculated using [RHO]NMHC-liq.
Example:
eNMHCh = 0.025 g/mi
eNMOGh = 0.025 · 1.03 = 0.026 g/mi
Where:
eNMOGcomp = weighted FTP composite mass emission rate of NMOG.
eNMHCcomp = weighted FTP composite mass emission rate of NMHC, calculated using [RHO]NMHC-liq.
VPEtOH = volume percentage of ethanol in the test fuel. Use good engineering judgment to determine this value either as specified in 40 CFR 1065.710 or based on blending volumes, taking into account any denaturant.
Example:
eNMHCcomp = 0.025 g/mi
VPEtOH = 10.1%
eNMOGcomp = 0.025 · (1.0302 + 0.0071 · 10.1) = 0.0275 g/mi
Where:
eNMOG-FTPct = mass emission rate of NMOG from the transient portion of the FTP cold-start test (generally known as bag 1).
eNMHC-FTPct = mass emission rate of NMHC from the transient portion of the FTP cold-start test (bag 1), calculated using [RHO]NMHC-liq.
Example:
eNMHC-FTPct = 0.052 g/mi
VPEtOH = 10.1%
eNMOG-FTPct = 0.052 · (1.0246 + 0.0079 · 10.1) = 0.0574 g/mi
Where:
eNMOG-FTPcs-hs = mass emission rate of NMOG from the stabilized portion of the FTP test (bag 2 or bag 4).
eNMHC-FTPcs-hs = mass emission rate of NMHC from the stabilized portion of the FTP test (bag 2 or bag 4), calculated using [RHO]NMHC-liq.
Where:
eNMOG-FTPht = mass emission rate of NMOG from the transient portion of the FTP hot-start test (bag 3).
eNMHC-FTPht = mass emission rate of NMHC from the transient portion of the FTP hot-start test (bag 3), calculated using [RHO]NMHC-liq.
40 C.F.R. §1066.635