# 40 CFR § 86.088-2 - Definitions.

§ 86.088-2 Definitions.

The definitions in § 86.085-2 remain effective. The definitions in this section apply beginning with the 1988 model year.

Composite NOXstandard, for a manufacturer which elects to average light-duty trucks subject to the NOX standard of § 86.088-9(a)(iii)(A) together with those subject to the NOX standard of § 86.088-9(a)(iii)(B) in the light-duty truck NOX averaging program, means that standard calculated according to the following equation and rounded to the nearest one-tenth gram per mile:

$\frac{\left[\left({\mathrm{PROD}}_{A}\right)\left({\mathrm{STD}}_{A}\right)+\left({\mathrm{PROD}}_{B}\right)\left({\mathrm{STD}}_{B}\right)\right]}{\left({\mathrm{PROD}}_{A}\right)+\left({\mathrm{PROD}}_{B}\right)}=\text{Manufacturer's Composite}{\mathrm{NO}}_{x}\phantom{\rule{0ex}{0ex}}\text{Standard,}$

Where:
PRODA = The manufacturer's total light-duty truck production for those engine families subject to the standard of § 86.088-9(a)(iii)(A) and included in the average for a given model year,
STDA = The NOX standard of § 86.088-9(a)(iii)(A),
PRODB = The manufacturer's total light-duty truck production for those engine families subject to the standard of § 86.088-9(a)(iii)(B) and included in the average for a given model year, and
STDB = The NOX standard of § 86.088-9(a)(iii)(B).

Critical emission-related components are those components which are designed primarily for emission control, or whose failure may result in a significant increase in emissions accompanied by no significant impairment (or perhaps even an improvement) in performance, driveability, and/or fuel economy as determined by the Administrator.

Critical emission-related maintenance means that maintenance to be performed on critical emission-related components.

Emission-related maintenance means that maintenance which does substantially affect emissions or which is likely to affect the emissions deterioration of the vehicle or engine during normal in-use operation, even if the maintenance is performed at some time other than that which is recommended.

Family NOXemission limit means the NOX emission level to which an engine family is certified in the light-duty truck NOX averaging program, expressed to one-tenth of a gram per mile accuracy.

Non-emission-related maintenance means that maintenance which does not substantially affect emissions and which does not have a lasting effect on the emissions deterioration of the vehicle or engine during normal in-use operation once the maintenance is performed.

Production-weighted NOXaverage means the manufacturer's production-weighted average NOX emission level, for certification purposes, of all of its light-duty truck engine families included in the NOX averaging program. It is calculated at the end of the model year by multiplying each family NOX emission limit by its respective production, summing those terms, and dividing the sum by the total production of the effected families. Those vehicles produced for sale in California or at high altitude shall each be averaged separately from those produced for sale in any other area.

Production-weighted particulate average means the manufacturer's production-weighted average particulate emission level, for certification purposes, of all of its diesel engine families included in the particulate averaging program. It is calculated at the end of the model year by multiplying each family particulate emission limit by its respective production, summing those terms, and dividing the sum by the total production of the effected families. Those vehicles produced for sale in California or at high altitude shall each be averaged separately from those produced for sale in any other area.

(Secs. 202, 203, 206, 207, 208, 301a, Clean Air Act, as amended; 42 U.S.C. 7521, 7522, 7525, 7541, 7542, 7601a)
[50 FR 10648, Mar. 15, 1985]