# 40 CFR § 86.090-2 - Definitions.

§ 86.090-2 Definitions.

The definitions in § 86.088-2 remain effective. The definitions in this section apply beginning with the 1990 model year.

Averaging for heavy-duty engines means the exchange of NOX and particulate emission credits among engine families within a given manufacturer's product line.

Averaging set means a subcategory of heavy-duty engines within which engine families can average and trade emission credits with one other.

Banking means the retention of heavy-duty engine NOX and particulate emission credits, by the manufacturer generating the emission credits, for use in future model year certification programs as permitted by regulation.

Composite particulate standard, for a manufacturer which elects to average light-duty vehicles and light-duty trucks together in either the petroleum-fueled or methanol-fueled light-duty particulate averaging program, means that standards calculated using the following equation and rounded to the nearest one-hundredth (0.01) of a gram per mile:

$\left({\mathrm{PROD}}_{\mathrm{LDV}}\right)\frac{\left({\mathrm{STD}}_{\mathrm{LDV}}\right)+\left({\mathrm{PROD}}_{\mathrm{LDT}}\right)}{\left({\mathrm{PROD}}_{\mathrm{LDV}}\right)+\left({\mathrm{PROD}}_{\mathrm{LDT}}\right)}\left({\mathrm{STD}}_{\mathrm{LDT}}\right)=\begin{array}{c}\text{Manufacturer composite}\\ \text{particulate standard}\end{array}$
Where:
PRODLDV represents the manufacturer's total petroleum-fueled diesel or methanol-fueled diesel light-duty vehicle production for those engine families being included in the appropriate average for a given model year.
STDLDV represents the light-duty vehicle particulate standard.
PRODLDT represents the manufacturer's total petroleum-fueled diesel or methanol-fueled diesel light-duty truck production for those engine families being included in the appropriate average for a given model year.
STDLDT represents the light-duty truck particulate standard.

Dedicated vehicle (or engine) means any motor vehicle (or motor vehicle engine) engineered and designed to be operated using a single fuel. Flexible fuel vehicles and multi-fuel vehicles are not dedicated vehicles.

Diesel means type of engine with operating characteristics significantly similar to the theoretical Diesel combustion cycle. The non-use of a throttle during normal operation is indicative of a diesel engine.

Dual fuel vehicle (or engine) means any motor vehicle (or motor vehicle engine) engineered and designed to be operated on two different fuels, but not on a mixture of fuels.

Emission credits mean the amount of emission reductions or exceedances, by a heavy-duty engine family, below or above the emission standard, respectively. Emission credits below the standard are considered as “positive credits,” while emission credits above the standard are considered as “negative credits.” In addition, “projected credits” refer to emission credits based on the projected U.S. production volume of the engine family. “Reserved credits” are emission credits generated within a model year waiting to be reported to EPA at the end of the model year. “Actual credits” refer to emission credits based on actual U.S. production volumes as contained in the end-of-year reports submitted to EPA. Some or all of these credits may be revoked if EPA review of the end of year reports or any subsequent audit actions uncover problems or errors.

Family emission limit (FEL) means an emission level declared by the manufacturer which serves in lieu of an emission standard for certification purposes in any of the averaging, trading, or banking programs. FELs must be expressed to the same number of decimal places as the applicable emission standard. The FEL for an engine family using NOX or particulate NCPs must equal the value of the current NOX or particulate emission standard.

Flexible fuel vehicle (or engine) means any motor vehicle (or motor vehicle engine) engineered and designed to be operated on any mixture of two or more different fuels.

Methanol-fueled means any motor vehicle or motor vehicle engine that is engineered and designed to be operated using methanol fuel (i.e., a fuel that contains at least 50 percent methanol (CH3OH) by volume) as fuel. Flexible fuel vehicles are methanol-fueled vehicles.

Non-oxygenated hydrocarbon means organic emissions measured by a flame ionization detector, excluding methanol.

Otto-cycle means type of engine with operating characteristics significantly similar to the theoretical Otto combustion cycle. The use of a throttle during normal operation is indicative of an Otto-cycle engine.

Primary intended service class has the meaning given in 40 CFR 1036.140.

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 light-duty 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.

Throttle means a device used to control an engine's power output by limiting the amount of air entering the combustion chamber.

Total hydrocarbon equivalent means the sum of the carbon mass emissions of non-oxygenated hydrocarbons, methanol, formaldehyde or other organic compounds that are separately measured, expressed as gasoline-fueled vehicle hydrocarbons. In the case of exhaust emissions, the hydrogen-to-carbon ratio of the equivalent hydrocarbon is 1.85:1. In the case of diurnal and hot soak emissions, the hydrogen-to-carbon ratios of the equivalent hydrocarbons are 2.33:1 and 2.2:1, respectively.

Trading means the exchange of heavy-duty engine NOX or particulate emission credits between manufacturers.

Useful life means:

(a) For light-duty vehicles a period of use of 5 years or 50,000 miles, whichever first occurs.

(b) For a light-duty truck engine family, a period of use of 11 years or 120,000 miles, whichever occurs first.

(c) For an Otto-cycle heavy-duty engine family, a period of use of 8 years of 110,000 miles, whichever first occurs.

(d) For a diesel heavy-duty engine family:

(1) For light heavy-duty diesel engines, period of use of 8 years or 110,000 miles, whichever first occurs.

(2) For medium heavy-duty diesel engines, a period of use of 8 years or 185,000 miles, whichever first occurs.

(3) For heavy heavy-duty diesel engines, a period of use of 8 years or 290,000 miles, whichever first occurs.

(e) As an option for both light-duty truck and heavy-duty engine families, an alternative useful life period assigned by the Administrator under the provisions of paragraph (f) of § 86.090-21.

(f) The useful-life period for purposes of the emissions defect warranty and emissions performance warranty shall be a period of 5 years/50,000 miles whichever first occurs, for light-duty trucks, Otto cycle heavy-duty engines and light heavy-duty diesel engines. For all other heavy-duty diesel engines the aforementioned period is 5 years/100,000 miles, whichever first occurs. However, in no case may this period be less than the manufacturer's basic mechanical warranty period for the engine family.

[55 FR 30612, July 26, 1990, as amended at 60 FR 34334, June 30, 1995; 62 FR 31233, June 6, 1997; 76 FR 57376, Sept. 15, 2011]