; (2) uses gasoline for propulsion or any other operation of the motor vehicle, including the engine thereof; and (3) is a model year 2028 or later motor vehicle. 262. High-octane test fuels (a) E20 certification fuel Except as provided in subsections (b) and (c), manufacturers producing motor vehicles described in section 261(b) shall use a test fuel consisting of gasoline and 19.4 to 20 volume percent ethanol with a minimum 95 research octane number in— (1) emissions testing and certification under section 206(a); and (2) fuel economy testing and calculation procedures under section 32904(c) of title 49, United States Code. (b) E25 to E30 certification fuel As an alternative to the test fuel described in subsection (a), manufacturers producing motor vehicles described in section 261(b) may use a test fuel consisting of gasoline and 24.3 to 30 volume percent ethanol with a minimum 98 research octane number in— (1) emissions testing and certification under section 206(a); and (2) fuel economy testing and calculation procedures under section 32904(c) of title 49, United States Code. (c) Model year 2033 and later model years Notwithstanding subsections (a) and (b), beginning in model year 2033, manufacturers of motor vehicles described in section 261(b) shall use the gasoline test fuel described in subsection (b) in— (1) emissions testing and certification under section 206(a); and (2) fuel economy testing and calculation procedures under section 32904(c) of title 49, United States Code. (d) Formulation The test fuels described in subsections (a) and (b) shall be produced by adding neat or denatured fuel ethanol to the gasoline criteria emissions test fuel required for use in model year 2022 and later motor vehicles. (e) Test fuel equations For purposes of— (1) testing and calculation procedures under section 206(a), the emissions of motor vehicles using the test fuels described in subsection (a) or (b) shall be based exclusively on actual measured emissions