40 CFR § 88.311-93 - Emissions standards for Inherently Low-Emission Vehicles.
(1) Emissions Testing Procedures. A vehicle shall be certified as an ILEV if that vehicle satisfies the following conditions:
(i) The vehicle shall be certified under the appropriate exhaust emissions standards from paragraph (c) or (d) of this section depending on the vehicle's weight classification.
(ii) The vehicle shall be certified as having fuel vapor emissions which are five or less total grams per test as measured by the current Federal Test Procedure (FTP), modified for ILEV certification, from 40 CFR part 86, subpart B for LDVs and LDTs and from 40 CFR part 86, subpart M for HDVs.
(A) After disabling any and all auxiliary emission control devices (canister, purge system, etc.) related to control of evaporative emissions, the fuel vapor emissions shall be measured using the FTP regulations in effect at the time the vehicle is to be certified as an ILEV. For purposes of this section, the vehicle's fuel vapor emissions shall consist of the total grams of diurnal, hot soak, running loss, and resting loss emissions, as appropriate, for the particular fuel/vehicle/engine combination to be tested. In determining ILEV evaporative emissions, the diurnal emissions measurement procedure shall consist of a single diurnal heat build using an ambient or fuel temperature range of 72°-96 °F (22°-36 °C), as appropriate for the applicable FTP regulations (40 CFR part 86).
(B) Conventional Federal Test Procedure. A vehicle with no evaporative emissions control system components may have its evaporative emissions certified for its particular GVWR weight class/subclass if it passes the conventional evaporative emissions FTP from 40 CFR part 86, subpart B for LDVs and LDTs or from 40 CFR part 86, subpart M for HDVs, as applicable.
(iii) The vehicle must meet other special requirements applicable to conventional or clean-fuel vehicles and their fuels as described in any other parts of this chapter, including 40 CFR parts 86 and 88.
(2) Vehicles which have a closed or sealed fuel system may be certified at the administrator's option by engineering evaluation in lieu of testing. These vehicles will be certified as ILEVs only if a leak in the fuel system would result in the vehicle becoming inoperative due to loss of fuel supply, or if half the fuel escapes within 24 hours.
(b) Identification. In the application for a vehicle's certification as an ILEV, the manufacturer or the manufacturer's agent shall provide for positive identification of the vehicle's status as an ILEV in the vehicle's Vehicle Emission Control Information (VECI) label in accordance with 40 CFR 86.094-35 and 86.095-35. The label shall contain a highlighted statement (e.g., underscored or boldface letters) that the vehicle is certified to applicable emission standards for ILEV exhaust and evaporative emission standards.
(c) Light-duty vehicles and light-duty trucks. ILEVs in LDV and LDT classes shall have exhaust emissions which do not exceed the LEV exhaust emission standards for NMOG, CO, HCHO, and PM and the ULEV exhaust emission standards for NOX listed in Tables A104-1 through A104-6 for light-duty CFVs. Exhaust emissions shall be measured in accordance with the test procedures specified in § 88.104-94(k). An ILEV must be able to operate on only one fuel, or must be certified as an ILEV on all fuels on which it can operate. These vehicles shall also comply with all requirements of 40 CFR part 86 which are applicable to conventional gasoline-fueled, methanol-fueled, diesel-fueled, natural gas-fueled or liquified petroleum gas-fueled LDVs/LDTs of the same vehicle class and model year.
(d) Heavy-duty vehicles. ILEVs in the HDV class shall have exhaust emissions which do not exceed the exhaust emission standards in grams per brake horsepower-hour listed in § 88.105-94(d). Exhaust emissions shall be measured in accordance with the test procedures specified in § 88.105-94(e). An ILEV must be able to operate on only one fuel, or must be certified as an ILEV on all fuels on which it can operate. These vehicles shall also comply with all requirements of 40 CFR part 86 which are applicable in the case of conventional gasoline-fueled, methanol-fueled, diesel-fueled, natural gas-fueled or liquified petroleum gas-fueled HDVs of the same weight class and model year.