# 40 CFR § 80.45 - Complex emissions model.

(a) Definition of terms. For the purposes of this section, the following definitions shall apply:

(b) Weightings and baselines for the complex model.

(1) The weightings for normal and higher emitters (w1 and w2, respectively) given in table 1 shall be used to calculate the exhaust emission performance of any fuel for the appropriate pollutant and Phase:

Table 1 - Normal and Higher Emitter Weightings for Exhaust Emissions

Phase I | Phase II | |||
---|---|---|---|---|

VOC & toxics | NOX | VOC & toxics | NOX | |

Normal Emitters (w1) | 0.52 | 0.82 | 0.444 | 0.738 |

Higher Emitters (w2) | 0.48 | 0.18 | 0.556 | 0.262 |

(2) The following properties of the baseline fuels shall be used when determining baseline mass emissions of the various pollutants:

Table 2 - Summer and Winter Baseline Fuel Properties

Fuel property | Summer | Winter |
---|---|---|

Oxygen (wt %) | 0.0 | 0.0 |

Sulfur (ppm) | 339 | 338 |

RVP (psi) | 8.7 | 11.5 |

E200 (%) | 41.0 | 50.0 |

E300 (%) | 83.0 | 83.0 |

Aromatics (vol %) | 32.0 | 26.4 |

Olefins (vol %) | 9.2 | 11.9 |

Benzene (vol %) | 1.53 | 1.64 |

(3) The baseline mass emissions for VOC, NOX and toxics given in tables 3, 4 and 5 of this paragraph (b)(3) shall be used in conjunction with the complex model during the appropriate Phase and season:

Table 3 - Baseline Exhaust Emissions

Exhaust pollutant | Phase I | Phase II | ||
---|---|---|---|---|

Summer (mg/mile) | Winter (mg/mile) | Summer (mg/mile) | Winter (mg/mile) | |

VOC | 446.0 | 660.0 | 907.0 | 1341.0 |

NOX | 660.0 | 750.0 | 1340.0 | 1540.0 |

Benzene | 26.10 | 37.57 | 53.54 | 77.62 |

Acetaldehyde | 2.19 | 3.57 | 4.44 | 7.25 |

Formaldehyde | 4.85 | 7.73 | 9.70 | 15.34 |

1,3-Butadiene | 4.31 | 7.27 | 9.38 | 15.84 |

POM | 1.50 | 2.21 | 3.04 | 4.50 |

Table 4 - Baseline Non-Exhaust Emissions (Summer Only)

Non-exhaust pollutant | Phase I | Phase II | ||
---|---|---|---|---|

Region 1 (mg/mile) | Region 2 (mg/mile) | Region 1 (mg/mile) | Region 2 (mg/mile) | |

VOC | 860.48 | 769.10 | 559.31 | 492.07 |

Benzene | 9.66 | 8.63 | 6.24 | 5.50 |

Table 5 - Total Baseline VOC, NOX and Toxics Emissions

Pollutant | Summer (mg/mile) | Winter (mg/mile) | ||||||
---|---|---|---|---|---|---|---|---|

Phase I | Phase II | Phase I | Phase II | |||||

Region 1 | Region 2 | Region 1 | Region 2 | Region 1 | Region 2 | Region 1 | Region 2 | |

NOX | 660.0 | 660.0 | 1340.0 | 1340.0 | 750.0 | 750.0 | 1540.0 | 1540.0 |

VOC | 1306.5 | 1215.1 | 1466.3 | 1399.1 | 660.0 | 660.0 | 1341.0 | 1341.0 |

Toxics | 48.61 | 47.58 | 86.34 | 85.61 | 58.36 | 58.36 | 120.55 | 120.55 |

(c) VOC performance.

(1) The exhaust VOC emissions performance of gasolines shall be given by the following equations:

(i) Consolidated VOC equation for normal emitters.

(ii) VOC equation for higher emitters.

(iii) Flat line extrapolations.

(A) During Phase I, fuels with E200 values greater than 65.83 percent shall be evaluated with the E200 fuel parameter set equal to 65.83 percent when calculating Yvoc(t) and VOCE using the equations described in paragraphs (c)(1) (i) and (ii) of this section. Fuels with E300 values greater than E300* (calculated using the equation E300* = 80.32 + [0.390 × ARO]) shall be evaluated with the E300 parameter set equal to E300* when calculating VOCE using the equations described in paragraphs (c)(1) (i) and (ii) of this section. For E300* values greater than 94, the linearly extrapolated model presented in paragraph (c)(1)(iv) of this section shall be used.

(B) During Phase II, fuels with E200 values greater than 65.52 percent shall be evaluated with the E200 fuel parameter set equal to 65.52 percent when calculating VOCE using the equations described in paragraphs (c)(1) (i) and (ii) of this section. Fuels with E300 values greater than E300* (calculated using the equation E300* = 79.75 + [0.385 × ARO]) shall be evaluated with the E300 parameter set equal to E300* when calculating VOCE using the equations described in paragraphs (c)(1) (i) and (ii) of this section. For E300* values greater than 94, the linearly extrapolated model presented in paragraph (c)(1)(iv) of this section shall be used.

(C) During Phase II, fuels with an oxygen concentration greater than 4.0 weight percent and not more than 5.8 weight percent shall be evaluated with the OXY fuel parameter set equal to 4.0 percent by weight when calculating VOCE using the equations described in paragraphs (c)(1)(i) and (c)(1)(ii) of this section.

(iv) Linear extrapolations.

(A) The equations in paragraphs (c)(1) (i) and (ii) of this section shall be used within the allowable range of E300, E200, and ARO for the appropriate Phase, as defined in table 6:

Table 6 - Allowable Ranges of E200, E300, and ARO for the Exhaust VOC Equations in Paragraphs (c)(1)(i) and (ii) of This Section

Fuel parameter | Phase I | Phase II | ||
---|---|---|---|---|

Lower limit | Higher limit | Lower limit | Higher limit | |

E200 | 33.00 | 65.83 | 33.00 | 65.52 |

E300 | 72.00 | Variable
^{1} |
72.00 | Variable
^{2} |

ARO | 18.00 | 46.00 | 18.00 | 46.00 |

1 Higher E300 limit = lower of 94.0 or 80.32 + [0.390 × (ARO)].

2 Higher E300 limit = lower of 94.0 or 79.75 + [0.385 × (ARO)].

(B) For fuels with E200, E300 and/or ARO levels outside the ranges defined in table 6, YVOC(t) shall be defined:

(1) For Phase I:

(2) For Phase II:

(C) During Phase I, the “edge target” fuel shall be identical to the target fuel for all fuel parameters, with the following exceptions:

(1) If the E200 level of the target fuel is less than 33 volume percent, then the E200 value for the “edge target” fuel shall be set equal to 33 volume percent.

(2) If the aromatics level of the target fuel is less than 18 volume percent, then the ARO value for the “edge target” fuel shall be set equal to 18 volume percent.

(3) If the aromatics level of the target fuel is greater than 46 volume percent, then the ARO value for the “edge target” fuel shall be set equal to 46 volume percent.

(4) If the E300 level of the target fuel is less than 72 volume percent, then the E300 value for the “edge target” fuel shall be set equal to 72 volume percent.

(5) If the E300 level of the target fuel is greater than 95 volume percent, then the E300 value of the target fuel shall be set equal to 95 volume percent for the purposes of calculating VOC emissions with the Phase I equation given in paragraph (c)(1)(iv)(B) of this section.

(6) If [80.32 + (0.390 × ARO)] exceeds 94 for the target fuel, and the target fuel value for E300 exceeds 94, then the E300 value for the “edge target” fuel shall be set equal to 94 volume percent.

(7) If the E200 level of the target fuel is less than 33 volume percent, then ΔE200 shall be set equal to (E200−33 volume percent).

(8) If the E200 level of the target fuel equals or exceeds 33 volume percent, then ΔE200 shall be set equal to zero.

(9) If the aromatics level of the target fuel is less than 18 volume percent, then ΔARO shall be set equal to (ARO−18 volume percent). If the aromatics level of the target fuel is less than 10 volume percent, then ΔARO shall be set equal to −8 volume percent.

(10) If the aromatics level of the target fuel is greater than 46 volume percent, then ΔARO shall be set equal to (ARO−46 volume percent).

(11) If neither of the conditions established in paragraphs (c)(1)(iv)(C)(9) and (10) of this section are met, then ΔARO shall be set equal to zero.

(12) If the E300 level of the target fuel is less than 72 percent, then ΔE300 shall be set equal to (E300−72 percent).

(13) If the E300 level of the target fuel is greater than 94 volume percent and [80.32 + (0.390xARO)] also is greater than 94, then ΔE300 shall be set equal to (E300−94 volume percent). If the E300 level of the target fuel is greater than 95 volume percent and [80.32 + (0.390 × ARO)] also is greater than 94, then ΔE300 shall be set equal to 1 volume percent.

(14) If neither of the conditions established in paragraphs (c)(1)(iv)(C)(12) and (13) of this section are met, then ΔE300 shall be set equal to zero.

(D) During Phase II, the “edge target” fuel is identical to the target fuel for all fuel parameters, with the following exceptions:

(1) If the E200 level of the target fuel is less than 33 volume percent, then the E200 value for the “edge target” fuel shall be set equal to 33 volume percent.

(2) If the aromatics level of the target fuel is less than 18 volume percent, then the ARO value for the “edge target” fuel shall be set equal to 18 volume percent.

(3) If the aromatics level of the target fuel is greater than 46 volume percent, then the ARO value for the “edge target” fuel shall be set equal to 46 volume percent.

(4) If the E300 level of the target fuel is less than 72 volume percent, then the E300 value for the “edge target” fuel shall be set equal to 72 volume percent.

(5) If the E300 level of the target fuel is greater than 95 volume percent, then the E300 value of the target fuel shall be set equal to 95 volume percent for the purposes of calculating VOC emissions with the Phase II equation given in paragraph (c)(1)(iv)(B) of this section.

(6) If [79.75 + (0.385 × ARO)] exceeds 94 for the target fuel, and the target fuel value for E300 exceeds 94, then the E300 value for the “edge target” fuel shall be set equal to 94 volume percent.

(7) If the E200 level of the target fuel is less than 33 volume percent, then ΔE200 shall be set equal to (E200−33 volume percent).

(8) If the E200 level of the target fuel equals or exceeds 33 volume percent, then ΔE200 shall be set equal to zero.

(9) If the aromatics level of the target fuel is less than 18 volume percent and greater than or equal to 10 volume percent, then ΔARO shall be set equal to (ARO−18 volume percent). If the aromatics level of the target fuel is less than 10 volume percent, then ΔARO shall be set equal to −8 volume percent.

(10) If the aromatics level of the target fuel is greater than 46 volume percent, then ΔARO shall be set equal to (ARO − 46 volume percent).

(11) If neither of the conditions established in paragraphs (c)(1)(iv)(D)(9) and (10) of this section are met, then ΔARO shall be set equal to zero.

(12) If the E300 level of the target fuel is less than 72 percent, then ΔE300 shall be set equal to (E300 − 72 percent).

(13) If the E300 level of the target fuel is greater than 94 volume percent and (79.75 + (0.385 × ARO)) also is greater than 94, then ΔE300 shall be set equal to (E300 − 94 volume percent). If the E300 level of the target fuel is greater than 95 volume percent and (79.75 + (0.385 × ARO)) also is greater than 94, then “E300 shall be set equal to 1 volume percent.

(2) The winter exhaust VOC emissions performance of gasolines shall be given by the equations presented in paragraph (c)(1) of this section with the RVP value set to 8.7 psi for both the baseline and target fuels.

(3) The nonexhaust VOC emissions performance of gasolines in VOC Control Region 1 shall be given by the following equations, where:

(i) During Phase I:

(ii) During Phase II:

(4) The nonexhaust VOC emissions performance of gasolines in VOC Control Region 2 shall be given by the following equations, where:

(i) During Phase I:

(ii) During Phase II:

(5) Winter VOC emissions shall be given by VOCE, as defined in paragraph (c)(2) of this section, using the appropriate baseline emissions given in paragraph (b)(3) of this section. Total nonexhaust VOC emissions shall be set equal to zero under winter conditions.

(6) Total VOC emissions.

(i) Total summer VOC emissions shall be given by the following equations:

(ii) Total winter VOC emissions shall be given by the following equations:

(7) Phase I total VOC emissions performance.

(i) The total summer VOC emissions performance of the target fuel in percentage terms from baseline levels shall be given by the following equations during Phase I:

(ii) The total winter VOC emissions performance of the target fuel in percentage terms from baseline levels shall be given by the following equations during Phase I:

(8) Phase II total VOC emissions performance.

(i) The total summer VOC emissions performance of the target fuel in percentage terms from baseline levels shall be given by the following equations during Phase II:

(ii) The total winter VOC emissions performance of the target fuel in percentage terms from baseline levels shall be given by the following equation during Phase II:

(d) NOXperformance.

(1) The summer NOX emissions performance of gasolines shall be given by the following equations:

(i) Consolidated equation for normal emitters.

(ii) Equation for higher emitters.

(iii) Flat line extrapolations.

(A) During Phase I, fuels with olefin levels less than 3.77 volume percent shall be evaluated with the OLE fuel parameter set equal to 3.77 volume percent when calculating NOX performance using the equations described in paragraphs (d)(1)(i) and (ii) of this section. Fuels with aromatics levels greater than 36.2 volume percent shall be evaluated with the ARO fuel parameter set equal to 36.2 volume percent when calculating NOX performance using the equations described in paragraphs (d)(1)(i) and (ii) of this section.

(B) During Phase II, fuels with olefin levels less than 3.77 volume percent shall be evaluated with the OLE fuel parameter set equal to 3.77 volume percent when calculating NOX performance using the equations described in paragraphs (d)(1)(i) and (ii) of this section. Fuels with aromatics levels greater than 36.8 volume percent shall be evaluated with the ARO fuel parameter set equal to 36.8 volume percent when calculating NOX performance using the equations described in paragraphs (d)(1)(i) and (ii) of this section.

(iv) Linear extrapolations.

(A) The equations in paragraphs (d)(1)(i) and (ii) of this section shall be used within the allowable range of SUL, OLE, and ARO for the appropriate Phase, as defined in the following table 7:

Table 7 - Allowable Ranges of SUL, OLE, and ARO for the NOX Equations in Paragraphs/(d)(1)(i) and (ii) of This Section

Fuel parameter | Phase I | Phase II | ||
---|---|---|---|---|

Low end | High end | Low end | High end | |

SUL | 10.0 | 450.0 | 10.0 | 450.0 |

OLE | 3.77 | 19.0 | 3.77 | 19.0 |

ARO | 18.0 | 36.2 | 18.0 | 36.8 |

(B) For fuels with SUL, OLE, and/or ARO levels outside the ranges defined in Table 7 of paragraph (d)(1)(iv)(A) of this section, YNOx(t) shall be defined as:

(2) For Phase II:

(C) For both Phase I and Phase II, the “edge target” fuel is identical to the target fuel for all fuel parameters, with the following exceptions:

(1) If the sulfur level of the target fuel is less than 10 parts per million, then the value of SUL for the “edge target” fuel shall be set equal to 10 parts per million.

(2) If the sulfur level of the target fuel is greater than 450 parts per million, then the value of SUL for the “edge target” fuel shall be set equal to 450 parts per million.

(3) If the aromatics level of the target fuel is less than 18 volume percent, then the value of ARO for the “edge target” fuel shall be set equal to 18 volume percent.

(4) If the olefins level of the target fuel is greater than 19 volume percent, then the value of OLE for the “edge target” fuel shall be set equal to 19 volume percent.

(5) If the E300 level of the target fuel is greater than 95 volume percent, then the E300 value of the target fuel shall be set equal to 95 volume percent for the purposes of calculating NOX emissions with the equations given in paragraph (d)(1)(iv)(B) of this section.

(6) If the sulfur level of the target fuel is less than 10 parts per million, then ΔSUL shall be set equal to (SUL−10 parts per million).

(7) If the sulfur level of the target fuel is greater than 450 parts per million, then ΔSUL shall be set equal to (SUL−450 parts per million).

(8) If the sulfur level of the target fuel is neither less than 10 parts per million nor greater than 450 parts per million, ΔSUL shall be set equal to zero.

(9) If the aromatics level of the target fuel is less than 18 volume percent and greater than 10 volume percent, then ΔARO shall be set equal to (ARO−18 volume percent). If the aromatics level of the target fuel is less than 10 volume percent, then ΔARO shall be set equal to −8 volume percent.

(10) If the aromatics level of the target fuel is greater than or equal to 18 volume percent, then ΔARO shall be set equal to zero.

(11) If the olefins level of the target fuel is greater than 19 volume percent, then ΔOLE shall be set equal to (OLE−19 volume percent).

(12) If the olefins level of the target fuel is less than or equal to 19 volume percent, then ΔOLE shall be set equal to zero.

(2) The winter NOX emissions performance of gasolines shall be given by the equations presented in paragraph (d)(1) of this section with the RVP value set to 8.7 psi.

(3) The NOX emissions performance of the target fuel in percentage terms from baseline levels shall be given by the following equations:

(e) Toxics performance -

(1) Summer toxics performance.

(i) Summer toxic emissions performance of gasolines in VOC Control Regions 1 and 2 shall be given by the following equations:

(ii) The percentage change in summer toxics performance in VOC Control Regions 1 and 2 shall be given by the following equations:

(2) Winter toxics performance.

(i) Winter toxic emissions performance of gasolines in VOC Control Regions 1 and 2 shall be given by the following equation, evaluated with the RVP set at 8.7 psi:

(ii) The percentage change in winter toxics performance in VOC Control Regions 1 and 2 shall be given by the following equation:

(3) The year-round toxics performance in VOC Control Regions 1 and 2 shall be derived from volume-weighted performances of individual batches of fuel as described in § 80.67(g).

(4) Exhaust benzene emissions shall be given by the following equation, subject to paragragh (e)(4)(iii) of this section:

(i) Consolidated equation for normal emitters.

(ii) Equation for higher emitters.

(iii) If the aromatics value of the target fuel is less than 10 volume percent, then an aromatics value of 10 volume percent shall be used when evaluating the equations given in paragraphs (e)(4) (i) and (ii) of this section. If the E300 value of the target fuel is greater than 95 volume percent, then an E300 value of 95 volume percent shall be used when evaluating the equations in paragraphs (e)(4)(i) and (ii) of this section.

(5) Formaldehyde mass emissions shall be given by the following equation, subject to paragraphs (e)(5) (iii) and (iv) of this section:

(i) Consolidated equation for normal emitters.

(ii) Equation for higher emitters.

(iii) If the aromatics value of the target fuel is less than 10 volume percent, then an aromatics value of 10 volume percent shall be used when evaluating the equations given in paragraphs (e)(5) (i) and (ii) of this section. If the E300 value of the target fuel is greater than 95 volume percent, then an E300 value of 95 volume percent shall be used when evaluating the equations given in paragraphs (e)(5) (i) and (ii) of this section.

(iv) When calculating formaldehyde emissions and emissions performance, oxygen in the form of alcohols which are more complex or have higher molecular weights than ethanol shall be evaluated as if it were in the form of ethanol. Oxygen in the form of methyl ethers other than TAME and MTBE shall be evaluated as if it were in the form of MTBE. Oxygen in the form of ethyl ethers other than ETBE shall be evaluated as if it were in the form of ETBE. Oxygen in the form of non-methyl, non-ethyl ethers shall be evaluated as if it were in the form of ETBE. Oxygen in the form of methanol or non-alcohol, non-ether oxygenates shall not be evaluated with the Complex Model, but instead must be evaluated through vehicle testing per § 80.48.

(6) Acetaldehyde mass emissions shall be given by the following equation, subject to paragraphs (e)(6) (iii) and (iv) of this section:

(i) Consolidated equation for normal emitters.

(ii) Equation for higher emitters.

(iii) If the aromatics value of the target fuel is less than 10 volume percent, then an aromatics value of 10 volume percent shall be used when evaluating the equations given in paragraphs (e)(6) (i) and (ii) of this section. If the E300 value of the target fuel is greater than 95 volume percent, then an E300 value of 95 volume percent shall be used when evaluating the equations given in paragraphs (e)(6) (i) and (ii) of this section.

(iv) When calculating acetaldehyde emissions and emissions performance, oxygen in the form of alcohols which are more complex or have higher molecular weights than ethanol shall be evaluated as if it were in the form of ethanol. Oxygen in the form of methyl ethers other than TAME and MTBE shall be evaluated as if it were in the form of MTBE. Oxygen in the form of ethyl ethers other than ETBE shall be evaluated as if it were in the form of ETBE. Oxygen in the form of non-methyl, non-ethyl ethers shall be evaluated as if it were in the form of ETBE. Oxygen in the form of methanol or non-alcohol, non-ether oxygenates shall not be evaluated with the Complex Model, but instead must be evaluated through vehicle testing per § 80.48.

(7) 1,3-butadiene mass emissions shall be given by the following equations, subject to paragraph (e)(7)(iii) of this section:

(i) Consolidated equation for normal emitters.

(ii) Equation for higher emitters.

(iii) If the aromatics value of the target fuel is less than 10 volume percent, then an aromatics value of 10 volume percent shall be used when evaluating the equations given in paragraphs (e)(7) (i) and (ii) of this section. If the E300 value of the target fuel is greater than 95 volume percent, then an E300 value of 95 volume percent shall be used when evaluating the equations given in paragraphs (e)(7) (i) and (ii) of this section.

(8) Polycyclic organic matter mass emissions shall be given by the following equation:

(9) Nonexhaust benzene emissions in VOC Control Region 1 shall be given by the following equations for both Phase I and Phase II:

(10) Nonexhaust benzene emissions in VOC Control Region 2 shall be given by the following equations for both Phase I and Phase II:

(f) Limits of the model.

(1) The equations described in paragraphs (c), (d), and (e) of this section shall be valid only for fuels with fuel properties that fall in the following ranges for reformulated gasolines and conventional gasolines:

(i) For reformulated gasolines:

Fuel property | Acceptable range |
---|---|

Oxygen | 0.0-5.8 weight percent. |

Sulfur | 0.0-500.0 parts per million by weight. |

RVP | 6.4-10.0 pounds per square inch. |

E200 | 30.0-70.0 percent evaporated. |

E300 | 70.0-100.0 percent evaporated. |

Aromatics | 0.0-50.0 volume percent. |

Olefins | 0.0-25.0 volume percent. |

Benzene | 0.0-2.0 volume percent. |

(ii) For conventional gasoline:

Fuel property | Acceptable range |
---|---|

Oxygen | 0.0-5.8 weight percent. |

Sulfur | 0.0-1000.0 parts per million by weight. |

RVP | 6.4-11.0 pounds per square inch. |

E200 | 30.0-70.0 evaporated percent. |

E300 | 70.0-100.0 evaporated percent. |

Aromatics | 0.0-55.0 volume percent. |

Olefins | 0.0-30.0 volume percent. |

Benzene | 0.0-4.9 volume percent. |

(2) Fuels with one or more properties that do not fall within the ranges described in above shall not be certified or evaluated for their emissions performance using the complex emissions model described in paragraphs (c), (d), and (e) of this section.

The following state regulations pages link to this page.