The Hino FD17 high beam headlight uses an H4651 bulb size while low beam headlight applications require either an H4652 or H4656 bulb size. The replacement chart covers vehicle production years spanning 1988 to 1991 with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The H4651, H4652, and H4656 are all ANSI-standardized sealed beam units operating at 12V. Each follows the 4x6-inch rectangular sealed beam format, meaning the entire lens-reflector-filament assembly is replaced as a single unit rather than swapping an internal bulb.
The Hino FD17 uses the H4651 sealed beam for the high beam position across all four model years covered in the specifications, from 1988-1991, making it the most consistent fitment in the dataset.
The low beam position on the Hino FD17 does not follow a uniform fitment across the same period. The 1988 and 1991 model years use the H4652, while the 1989-1990 model years use the H4656 instead.
Although the H4651 and H4652 share the same 4x6-inch rectangular sealed beam housing and 12V rating, they are distinct ANSI part numbers. The H4652 is described as a variant of the H4651, with the two types assigned to different beam positions rather than used interchangeably.
The H4656 shares the same physical format and voltage rating as the H4651 and H4652 but carries its own ANSI designation, indicating differences in light output or beam pattern characteristics specific to its intended application.
Because all three sealed beam types in these specifications conform to ANSI standards recognized in both the United States and Canada, the physical housing dimensions are standardized across manufacturers, though the beam designations still govern correct fitment by position and model year.