Hino FD2320 headlight bulbs utilize H4651 size for high beam and H4656 size for low beam applications. The replacement chart covers 2003 to 2004 vehicle production specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Hino FD2320 uses the H4651 bulb type for high beam headlights across the 2003-2004 model years, and the H4656 for low beam headlights across the same years.
Both the H4651 and H4656 are ANSI-standardized sealed beam units recognized in the United States and Canada, meaning their physical and electrical characteristics conform to a defined industry specification rather than varying by manufacturer.
Both types take the form of a 4x6-inch rectangular sealed beam unit, a format in which the lens, reflector, and filament are fused into a single glass assembly rather than housing a separate replaceable bulb inside.
Because both units are sealed beam assemblies, the entire headlight unit is replaced when the filament fails, rather than swapping an internal bulb.
Both the H4651 and H4656 operate at 12 volts, which is consistent with standard automotive electrical systems.
The H4651 and H4656 share the same 4x6-inch rectangular sealed beam form factor, but they are not interchangeable. The H4651 is specified for the high beam position and the H4656 for the low beam position on the Hino FD2320.