The Freightliner FS65 headlight bulb sizes include H6054 and H4651 for high beam applications, along with H6054 and H4656 for low beam configurations, with each bulb size corresponding to specific lighting functions. The replacement chart covers 1996 through 2008 production years and details bulb size specifications for headlight applications across the model range.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The H6054 is a sealed beam halogen bulb operating in a rectangular form factor, rated for use in both high beam and low beam headlight positions. Its dual-function compatibility across both circuits is a defining characteristic of this bulb type.
The Freightliner FS65 uses the H6054 bulb for both high beam and low beam headlights across the 1996-2008 model years, making it the dominant bulb specification throughout the vehicle's production run in standard configuration.
The H6054 is a sealed beam unit, meaning the lens, reflector, and filament are fused into a single assembly. Replacement requires swapping the entire unit rather than just an internal bulb.
The 1996-1997 Freightliner FS65 Cab Over Engine configuration uses different bulb sizes than the standard variant, with the H4651 specified for the high beam position and the H4656 specified for the low beam position.
The H4651 and H4656 are rectangular sealed beam halogen bulbs that share the same physical housing size but carry different beam pattern designations. The H4651 is a high beam unit and the H4656 is a low beam unit, and the two are not interchangeable despite their similar form factor.
Because the Cab Over Engine variant of the FS65 uses position-specific sealed beams (H4651 for high, H4656 for low), installing the incorrect unit in either socket would result in the wrong beam pattern for that circuit.
The standard FS65 configuration avoids this position-specific distinction entirely, as the H6054 serves both the high beam and low beam roles without differentiation between the two sockets.