The Oldsmobile Calais brake light requires a 2057 bulb size for proper installation and function within the rear lighting assembly. Data for the specified component covers the range from 1985 to 1987.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Oldsmobile Calais uses two distinct bulb types across its brake lighting system for the 1985-1987 model years: the 2057 for standard brake lights and the 1156 for the center high mount stop light.
The 2057 is a dual-filament bulb operating at 12V with a wattage split of 26.9W for the high-intensity filament and 8W for the low-intensity filament, making it suitable for combined stop and tail light functions.
The 2057 follows the ANSI standard recognized in both the United States and Canada and uses a BAY15d bayonet base, which features offset pins to ensure correct orientation during installation.
The 2057 is a brighter variant of the 1157, meaning the two share a similar dual-filament design but differ in output, and they are not directly interchangeable despite their physical resemblance.
The 1156 is a single-filament bulb rated at 12V and 21W, designed exclusively for on/off switching applications such as the center high mount stop light, which does not require a secondary low-intensity filament.
The 1156 uses a BA15s bayonet base, which has a single pin and allows rotation in either direction, distinguishing it from the dual-pin BAY15d base of the 2057.
Because the BA15s and BAY15d bases are physically different, the 1156 and 2057 are not interchangeable, and substituting one for the other in the Calais brake lighting system would result in an improper fit.
Both the 2057 and 1156 conform to ANSI standards applicable across the United States and Canada, indicating consistent electrical and physical specifications within those markets.