vehicle is at least 50 percent more efficient than the reference fuel-economy rating for such motor vehicle as determined under paragraph (2)(A), or (iii) $3,500, if the fuel-economy rating for such motor vehicle is at least 75 percent more efficient than the reference fuel-economy rating for such motor vehicle as determined under paragraph (2)(A). (b) New qualified fuel-Efficient motor vehicle For purposes of this section, the term new qualified fuel-efficient motor vehicle means a passenger automobile or light truck— (1) which is treated as a motor vehicle for purposes of title II of the Clean Air Act, (2) which achieves a fuel-economy rating that is more efficient than the reference fuel-economy rating for such motor vehicle for the model year, (3) for which standards are prescribed pursuant to section 32902 of title 49, United States Code, (4) the original use of which commences with the taxpayer, (5) which is acquired for use or lease by the taxpayer and not for resale, and (6) which is made by a manufacturer beginning with model year 2021. (c) Application with other credits (1) Business credit treated as part of general business credit So much of the credit which would be allowed under subsection (a) for any taxable year (determined without regard to this subsection) that is attributable to property of a character subject to an allowance for depreciation shall be treated as a credit listed in section 38(b) for such taxable year (and not allowed under subsection (a)). (2) Refundable personal credit (A) In general For purposes of this title, the credit allowed under subsection (a) for any taxable year (determined after application of paragraph (1)) shall be treated as a credit allowable under subpart C for such taxable year (and not allowed under subsection (a)). (B) Refundable credit may be transferred (i) In general A taxpayer may, in connection with the purchase of a new qualified fuel-efficient motor vehicle, transfer any refundable credit described in subparagraph (A) to any person who is in the trade