The Buick GS 455 front side marker bulb uses 194, 97, or 194NA size, while the rear side marker bulb uses 194 or 1157 size. The replacement chart covers 1970 to 1972 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 194 bulb is the most frequently specified type across the Buick GS 455 side marker positions, appearing in both front and rear locations for the 1972 model year and in the rear position for 1970.
The 194 is a T10 miniature wedge bulb rated at 12V and 3.78W, conforming to ANSI standards for the US and Canadian markets.
The 194NA, specified for the 1970 front side marker, shares the same T10 wedge form factor and 12V/3.78W electrical rating as the standard 194 but features natural amber glass rather than a clear envelope.
The amber tint of the 194NA is built into the glass itself, meaning the color output is produced by the bulb rather than by a colored lens or housing.
The 1971 front side marker on the Buick GS 455 uses the 97 bulb, a single-filament type with a BA15s bayonet base rated at 12V and 13W, making it considerably higher in wattage than the 194 used in other positions.
The BA15s base of the 97 bulb is a single-contact bayonet fitting, which is physically distinct from the wedge base of the 194 and 194NA, meaning these types are not interchangeable.
The 97 bulb is noted as a variant of the 1156, sharing its bayonet base family but differing in wattage and other electrical characteristics.
The 1971 rear side marker uses the 1157, a dual-filament bulb with a BAY15d bayonet base rated at 12V and 21W/5W, which is the only dual-filament bulb specified across all three model years in these positions.
The BAY15d base of the 1157 has offset pins to prevent incorrect installation, and its dual-filament design serves two independent brightness levels, distinguishing it from the single-filament 97 despite both using bayonet-style bases.
The front and rear side marker bulb specifications for the GS 455 differ across all three model years, indicating that the same bulb type was not used uniformly across both positions within any single year from 1970 to 1972.