The Hino SG19 high beam headlight uses an H4651 bulb size while low beam headlight applications require either H4656 or H4652 bulb sizes. The replacement chart covers vehicle production spanning 1987 to 1992 with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The H4651, H4656, and H4652 are all ANSI-standardized sealed beam units used in the Hino SG19, rated at 12V and housed in a 4x6-inch rectangular form factor. As sealed beam units, the lens, reflector, and filament are fused into a single assembly, meaning the entire unit is replaced rather than an internal bulb.
The H4651 is specified for the high beam headlight position across all listed model years of the SG19, covering 1987-1992 without variation.
The low beam headlight position uses two different sealed beam types depending on the model year. The H4652 is specified for 1987-1990, while the H4656 replaces it for 1991-1992.
The H4652 is described as a variant of the H4651. Both share the same 4x6-inch rectangular sealed beam format and 12V rating, though they serve distinct beam positions and are not interchangeable across those positions in the SG19's fitment data.
The H4656 and H4651 are separate ANSI designations despite sharing the same physical format and voltage rating. ANSI designations for sealed beam units encode beam pattern and light output characteristics, so units with different codes are not interchangeable even when their housings appear physically similar.
All three sealed beam types conform to ANSI standards recognized in both the United States and Canada, indicating compliance with North American automotive lighting regulations applicable at the time of the SG19's production years.