49 C.F.R. § 533.6
(a) Any reference to a class of light trucks manufactured by a manufacturer shall be deemed—
(c) For model years 2017 and later, a manufacturer is eligible to increase the fuel economy performance of light trucks in accordance with procedures established by the EPA set forth in 40 CFR part 600, subpart F, including any adjustments to fuel economy the EPA allows, such as for fuel consumption improvements related to air conditioning efficiency, off-cycle technologies, and hybridization and other performance-based technologies for full-size pickup trucks that meet the requirements specified in 40 CFR 86.1803. Manufacturers must provide reporting on these technologies as specified in § 537.7 of this chapter by the required deadlines.
(4) Off-cycle technologies using the alternative EPA-approved methodology. A manufacturer is eligible to increase its fuel economy performance through use of an off-cycle technology requiring an application request made to the EPA in accordance with 40 CFR 86.1869-12(d).
(i) Eligibility under the corporate average fuel economy (CAFE) program requires compliance with paragraphs (c)(4)(i)(A) through (C) of this section. Paragraphs (c)(4)(i)(A), (B), and (D) of this section apply starting in model year 2024.
(ii) Review and approval process. NHTSA will provide to EPA its views on the suitability of using the off-cycle technology to adjust vehicle fuel economy performance. NHTSA's evaluation and review will consider:
(iii) Safety.
(B) Approval granted for innovative and off-cycle technology credits under NHTSA's fuel efficiency program does not affect or relieve the obligation to comply with the Vehicle Safety Act (49 U.S.C. Chapter 301), including the “make inoperative” prohibition (49 U.S.C. 30122), and all applicable Federal motor vehicle safety standards issued thereunder (FMVSSs) (part 571 of this chapter). In order to generate off-cycle or innovative technology credits manufacturers must state—
(1) That each vehicle equipped with the technology for which they are seeking credits will comply with all applicable FMVSS(s); and
(2) Whether or not the technology has a fail-safe provision. If no fail-safe provision exists, the manufacturer must explain why not and whether a failure of the innovative technology would affect the safety of the vehicle.