Vehicle Innovation Act of 2023 This bill authorizes through FY2028 Department of Energy (DOE) activities to support the research, development, and commercialization of innovative vehicle technologies in partnership or collaboration with industry, fuel producers and energy suppliers, electric utilities, universities, and laboratories. DOE must conduct a research and development program on materials, technologies, and processes with the potential to substantially reduce petroleum use and the emissions of U.S. passenger and commercial vehicles, including in the areas of natural gas and hydrogen vehicle technologies, electrification of vehicle systems, and hydraulic hybrid technologies. DOE must seek opportunities to leverage resources and support initiatives of state and local governments in developing and promoting advanced vehicle technologies, manufacturing, and infrastructure. The bill also requires DOE to carry out a research, development, and commercial application program for advanced vehicle manufacturing technologies and practices, including innovative processes to increase the production rate and decrease the cost of advanced battery and fuel cell manufacturing. In addition, DOE must conduct a program on advanced technologies for medium- to heavy-duty commercial, vocational, recreational, and transit vehicles; conduct a competitive grant program to demonstrate the integration of multiple advanced technologies on Class 8 trucks and trailers; and undertake a pilot program for technologies to improve total machine or system efficiency for nonroad mobile equipment (e.g., agricultural, construction, air, and seaport equipment).