# 40 CFR § 86.1860-04 - How to comply with the Tier 2 and interim non-Tier 2 fleet average NOX standards.

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§ 86.1860-04 How to comply with the Tier 2 and interim non-Tier 2 fleet average NOX standards.

(a) The fleet average standards referred to in this section are the corporate fleet average standards for FTP exhaust NOX emissions set forth in: § 86.1811-04(d) for Tier 2 LDV/Ts and MDPVs (0.07 g/mi); § 86.1811-04(l)(3) for interim non-Tier 2 LDV/LLDTs (0.30 g/mi); and, § 86.1811-04(l)(3) for interim non-Tier 2 HLDT/ MDPVs (0.20 g/mi). Unless otherwise indicated in this section, the provisions of this section apply to all three corporate fleet average standards, except that the interim non-Tier 2 fleet average NOX standards do not apply to a manufacturer whose U.S. LDV/T and MDPV sales are 100% Tier 2 LDV/Ts and MDPVs.

(b)

(1) Each manufacturer must comply with the applicable fleet average NOX standard, or standards, on a sales weighted average basis, at the end of each model year, using the procedure described in this section.

(2) During a phase-in year, the manufacturer must comply with the applicable fleet average NOX standard for the required phase-in percentage for that year as specified in § 86.1811-04(k)(1), or for the alternate phase-in percentage as permitted under § 86.1811-04(k)(6).

(c)

(1)

(i) Each manufacturer must separately compute the sales weighted averages of the individual NOX emission standards to which it certified all its Tier 2 vehicles, interim non-Tier 2 LDV/LLDTs, and interim non-Tier 2 HLDT/MDPVs of a given model year as described in § 86.1804(l)(2).

(ii) For model years up to and including 2008, manufacturers must compute separate NOX fleet averages for Tier 2 LDV/LLDTs and Tier 2 HLDT/MDPVs.

(2)

(i) For model years up to and including 2008, if a manufacturer certifies its entire U.S. sales of Tier 2 or interim non-Tier 2 LDV/LLDTs or interim non-Tier 2 HLDT/MDPVs, to full useful life bins having NOX standards at or below the applicable fleet average NOX standard, that manufacturer may elect not to compute a fleet average NOX level for that category of vehicles. A manufacturer making such an election must not generate NOX credits for that category of vehicles for that model year.

(ii) For model years after 2008, if a manufacturer certifies its entire U.S. sales of Tier 2 vehicles to full useful life bins having NOX standards at or below 0.07 gpm, that manufacturer may elect not to compute a fleet average NOX level for its Tier 2 vehicles. A manufacturer making such an election must not generate NOX credits for that model year.

(d) The sales weighted NOX fleet averages determined pursuant to paragraph (c) of this section must be compared with the applicable fleet average standard; 0.07 g/mi for NOX for Tier 2 LDV/Ts and MDPVs, 0.30 g/mi for NOX for interim non-Tier 2 LDV/LLDTs, and 0.20 g/mi for NOx for interim non-Tier 2 HLDT/MDPVs. Each manufacturer must comply on an annual basis with the fleet average standards by:

(1) Showing that its sales weighted average NOX emissions of its LDV/LLDTs, HLDT/MDPVs or LDV/Ts, as applicable, are at or below the applicable fleet average standard; or

(2) If the sales weighted average is not at or below the applicable fleet average standard, by obtaining and applying sufficient Tier 2 NOX credits, interim non-Tier 2 LDV/LLDT NOX credits or interim non-Tier 2 HLDT/MDPV NOX credits, as appropriate, and as permitted under § 86.1861-04.

(i) Manufacturers may not use NMOG credits generated under the NLEV program in subpart R of this part to meet any Tier 2 or interim non-Tier 2 NOX fleet average standard.

(ii) Tier 2 NOX credits may not be used to meet any fleet average interim non-Tier 2 NOX standard except as permitted by § 86.1860-04(e)(1).

(iii) Interim non-Tier 2 NOX credits may not be used to meet the Tier 2 fleet average NOX standard.

(iv) Interim non-Tier 2 NOX credits from HLDT/MDPVs may not be used to meet the fleet average NOX standard for interim non-Tier 2 LDV/LLDTs, and interim non-Tier 2 credits from LDV/LLDTs may not be used to meet the fleet average NOX standard for interim non-Tier 2 HLDT/MDPVs.

(e) (1) Manufacturers that cannot meet the requirements of paragraph (d) of this section, may carry forward a credit deficit for three model years, but must not carry such deficit into the fourth year. When applying credits to reduce or eliminate a deficit under the fleet average standard for interim LDV/LLDTs or interim HLDT/MDPVs, that has been carried forward into a year subsequent to its generation, a manufacturer may apply credits from Tier 2 LDV/LLDTs or Tier 2 HLDT/MDPVs, respectively, as well as from the appropriate group of interim vehicles. A manufacturer must not use interim credits to reduce or eliminate any NOX credit deficit under the Tier 2 fleet average standard.

(2) A manufacturer carrying a credit deficit into the third year must generate or obtain credits to offset that deficit and apply them to the deficit at a rate of 1.2:1, (i.e. deficits carried into the third model year must be repaid with credits equal to 120 percent of the deficit).

(3) A manufacturer must not bank credits for future model years or trade credits to another manufacturer during a model year into which it has carried a deficit.

(f) Computing fleet average NOX emissions. (1) Manufacturers must separately compute these fleet NOX averages using the equation contained in paragraph (f)(2) of this section:

(i) Their Tier 2 LDV/LLDT and Tier 2 HLDT/MDPV fleet average NOX emissions for each model year through 2008;

(ii) Their combined Tier 2 LDV/T and MDPV fleet average NOX emissions for each model year after 2008;

(iii) Their interim non-Tier 2 LDV/LLDT fleet average NOX emissions for each model year through 2006; and

(iv) Their interim non-Tier 2 HLDT/MDPV fleet average NOX emissions for each model year through 2008.

(2) The equation for computing fleet average NOX emissions is as follows:

$\frac{\sum \left(N×{\mathrm{NO}}_{x}\text{emission standard}\right)}{\begin{array}{c}\text{Total number of vehicles of the appropriate category}\\ \text{(e.g., all LDV/Ts and MDPVs, or interim non-Tier 2}\\ \text{HLDT/MDPVs, etc.) sold including HEVs and ZEVs}\end{array}}$

Where:
N = The number of vehicles sold in the applicable category that were certified for each corresponding NOX emission bin. N must be based on vehicles counted to the point of first sale.
Emission standard = The individual full useful life NOX emission standard for each bin for which the manufacturer had sales.

(3) The results of the calculation in paragraph (f)(2) of this section must be rounded as required by § 86.1837-01.

(4) When approved in advance by the Administrator, the numerator in the equation in paragraph (f)(2) of this section may be adjusted downward by the product of the number of HEVs from each NOX emission bin times a HEV NOX contribution factor determined through mathematical estimation of the reduction in NOX emissions over the test procedure used to certify the HEVs. The reduction in NOX emissions must be determined using good engineering judgement and reflect the relation in actual full useful life NOX emissions to the full useful life NOX standards for the certification bin applicable to the vehicles. The Administrator may require that calculation of the HEV NOX contribution factor include vehicle parameters such as vehicle weight, portion of time during the test procedure that the HEV operates with zero exhaust emissions, zero emission range, NOX emissions from fuel-fired heaters and NOX emissions from electricity production and storage.

(g) Additional credits for vehicles certified to 150,000 mile useful lives.

(1) A manufacturer may certify any test group to an optional useful life of 15 years or 150,000 miles, whichever occurs first.

(2)

(i) For any test group certified to the optional 15 year/150,000 mile useful life, the manufacturer may generate additional NOX credits, except as prohibited in paragraph (g)(3) of this section.

(ii) The manufacturer must calculate these extra NOX credits, where permitted, by substituting an adjusted NOX standard for the applicable NOX standard from the full useful life certification bin when it calculates the applicable fleet average NOX emissions by the procedure in paragraph (f) of this section. The adjusted standard must be equal to the applicable full useful life NOX standard multiplied by 0.85 and rounded to one more decimal place than the number of decimal places as the applicable full useful life NOX standard.

(3) A manufacturer electing not to comply with applicable intermediate life standards as permitted under § 86.1811-04(c)(4) may not generate additional credits from vehicles certified to a useful life of 15 years/150,000 miles; except that, for bins where such intermediate life standards do not exist or are specifically deemed to be optional in § 86.1811-04(c)(4), the manufacturer may generate additional NOX credits from vehicles certified to a useful life of 15 years/150,000 miles.

(h) Additional credits for vehicles certified to low bins. A manufacturer may obtain additional NOX credits by certifying vehicles to bins 1 and/or 2 in model years from 2001 through 2005 subject to the following requirements:

(1) When computing the fleet average Tier 2 NOX emissions using the formula in paragraph (f)(2) of this section, the manufacturer may multiply the number of vehicles certified to bins 1 and 2 by the applicable multiplier shown in Table S04-11 when computing the denominator in the formula. These multipliers may not be used after model year 2005. The table follows:

Table S04-11 - Multipliers for Additional Tier 2 NOX Credits for Bin 1 and 2 LDV/Ts

Bin Model year Multiplier 73
2 2001, 2002, 2003, 2004, 2005 1.5
1 2001, 2002, 2003, 2004, 2005 2.0

(2) Optionally, instead of the process described in paragraph (h)(1) of this section, when computing Tier 2 NOX credits using the formula in § 86.1861-04(b)(1), the manufacturer may multiply the number of vehicles certified to bin 1 and bin 2 by the applicable multiplier shown in Table S04-11 in paragraph (h)(1) of this section when computing the “Total number of Tier 2 Vehicles Sold, Including ZEVs and HEVs”. These multipliers may not be used after model year 2005.

[65 FR 6866, Feb. 10, 2000, as amended at 66 FR 19310, Apr. 13, 2001]