The Freightliner XB Line uses an H4651 bulb size for high beam headlights and an H4656 bulb size for low beam headlights. The replacement chart covers 1995 to 1997 model production years 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 Freightliner XB Line uses the H4651 bulb for the high beam headlight position across the 1995-1997 model years.
The H4651 is a sealed beam rectangular lamp operating at 12 volts, rated at 37.5 watts, and designed for high beam applications in commercial vehicle fitments.
The low beam headlight position on the XB Line for the same 1995-1997 span takes the H4656 bulb.
The H4656 is also a sealed beam rectangular lamp, sharing the same general housing format as the H4651 but configured specifically for low beam output, with a different filament arrangement that produces the required downward light pattern.
Because the H4651 and H4656 are separate part numbers serving distinct beam functions, the two bulbs are not interchangeable with each other despite their physical similarities as sealed beam units.
Sealed beam lamps of the H46xx series integrate the reflector, lens, and filament into a single non-serviceable unit, meaning the entire assembly requires replacement when the filament fails rather than just an internal bulb.
The consistent bulb specifications across all three model years indicate that the XB Line did not undergo headlight system changes between 1995 and 1997, allowing a single replacement part to serve the full production range for each beam position.