The Buick Centurion front side marker uses a 194 or 97 bulb size, while the rear side marker requires a 194 or 1157 bulb size. The replacement chart covers 1971 to 1973 model 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 Buick Centurion uses three distinct bulb types across its front and rear side marker positions for the 1971-1973 model years: the 194, 97, and 1157.
The 194 is the most frequently specified bulb in these listings, covering both the front and rear side marker positions for the 1972-1973 model years.
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 wedge base of the 194 requires no locking mechanism, as the bulb is held in place by the socket itself, which is a defining characteristic of the T10 form factor.
For the 1971 Buick Centurion, the front and rear side marker positions each use a different bulb type, meaning the two positions are not interchangeable that year.
The 1971 front side marker uses the 97, a single-filament bulb with a BA15s bayonet base rated at 12V and 13W, noted as a variant of the 1156.
The BA15s bayonet base of the 97 features a single contact pin, which physically prevents substitution with dual-pin bayonet bulbs without modification.
The 1971 rear side marker uses the 1157, a dual-filament bulb with a BAY15d bayonet base rated at 12V and 21W/5W, conforming to ANSI standards.
The BAY15d base of the 1157 has offset pins that prevent it from being seated in a BA15s socket, making the 97 and 1157 mechanically incompatible despite both using bayonet-style bases.
The dual-filament design of the 1157 supports two independent brightness levels, a characteristic absent from both the 97 and the 194 used elsewhere in the Centurion's side marker system.