The Buick Opel high beam and low beam headlight bulbs utilize H6054 and H6024 size specifications. The replacement chart covers 1976 through 1979 production years with corresponding bulb size data.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The H6024 is a 7-inch round sealed beam unit operating at 12V, conforming to ANSI standards for the US and Canadian markets. It appears across both the high beam and low beam positions of the Buick Opel for the 1976-1978 model years.
The H6054 is a 5x7-inch rectangular sealed beam unit, also rated at 12V and built to ANSI standards for the US and Canadian markets. It is specified for both the high beam and low beam positions of the 1979 model year.
Both the H6024 and H6054 are sealed beam units, meaning the lens, reflector, and filament are fused into a single assembly. When a filament fails, the entire unit requires replacement rather than an internal bulb swap.
The H6024 and H6054 are not interchangeable. The round format of the H6024 and the rectangular format of the H6054 represent physically distinct housing shapes, and substituting one for the other is not supported by the specifications.
The high beam and low beam positions share the same bulb size for each model year across the Buick Opel, meaning a single sealed beam type serves both functions within a given year rather than separate dedicated units for each function.