§ 86.004-28 Compliance with emission standards.

(a)-(b) [Reserved]

(c)

(1) Paragraph (c) of this section applies to heavy-duty engines.

(2) The applicable exhaust emission standards (or family emission limits, as appropriate) for Otto-cycle engines and for diesel-cycle engines apply to the emissions of engines for their useful life.

(3) Since emission control efficiency generally decreases with the accumulation of service on the engine, deterioration factors will be used in combination with emission data engine test results as the basis for determining compliance with the standards.

(4)

(i) Paragraph (c)(4) of this section describes the procedure for determining compliance of an engine with emission standards (or family emission limits, as appropriate), based on deterioration factors supplied by the manufacturer. Deterioration factors shall be established using applicable emissions test procedures. NO_X plus NMHC deterioration factors shall be established based on the sum of the pollutants. When establishing deterioration factors for NO_X plus NMHC, a negative deterioration (emissions decrease from the official exhaust emissions test result) for one pollutant may not offset deterioration of the other pollutant. Where negative deterioration occurs for NO_X and/or NMHC, the official exhaust emission test result shall be used for purposes of determining the NO_X plus NMHC deterioration factor.

(ii) Separate exhaust emission deterioration factors, determined from tests of engines, subsystems, or components conducted by the manufacturer, shall be supplied for each engine-system combination. For Otto-cycle engines, separate factors shall be established for transient NMHC (NMHCE), CO, NO_X. NO_X plus NMHC, and idle CO, for those engines utilizing aftertreatment technology (e.g., catalytic converters). For diesel-cycle engines, separate factors shall be established for transient NMHC (NMHCE), CO, NO_X. NO_X plus NMHC and exhaust particulate. For diesel-cycle smoke testing, separate factors shall also be established for the acceleration mode (designated as “A”), the lugging mode (designated as “B”), and peak opacity (designated as “C”).

(iii)

(A) Paragraphs (c)(4)(iii)(A) (1) and (2) of this section apply to Otto-cycle HDEs.

(1) Otto-cycle HDEs not utilizing aftertreatment technology (e.g., catalytic converters). For transient NMHC (NMHCE), CO, NO_X. the official exhaust emission results for each emission data engine at the selected test point shall be adjusted by the addition of the appropriate deterioration factor. However, if the deterioration factor supplied by the manufacturer is less than zero, it shall be zero for the purposes of this paragraph.

(2) Otto-cycle HDEs utilizing aftertreatment technology (e.g., catalytic converters). For transient NMHC (NMHCE), CO, NO_X. and for idle CO, the official exhaust emission results for each emission data engine at the selected test point shall be adjusted by multiplication by the appropriate deterioration factor, except as otherwise provided in paragraph (c)(4)(iii)(A)(3) of this section. The deterioration factor must be calculated by dividing the exhaust emissions at full useful life by the stabilized mileage emission level (reference § 86.096-26(c)(4), e.g., 125 hours). However, if the deterioration factor supplied by the manufacturer is less than one, it shall be one for purposes of this paragraph (c)(4)(iii)(A)(2).