Saturn SL2 brake bulbs utilize 3157 and 2057 sizes, while the center high mount stop light requires PC175 or PC168 bulb sizes. The replacement chart covers 1991 through 2002 model years with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Saturn SL2 brake light circuit relies on two bulb types across its production run: the 2057 for model years 1991-1999 and the 3157 for model years 2000-2002.
The 3157 is a dual-filament wedge bulb in the T25 form factor, rated at 12V with a 27W high-filament and 7W low-filament draw, and it conforms to the ANSI standard used in the US and Canada.
The 2057 uses a BAY15d bayonet base rather than a wedge mount, operates at 12V with a 26.9W high-filament and 8W low-filament draw, and is classified as a brighter variant of the 1157 bulb.
Because the 3157 uses a wedge base and the 2057 uses a BAY15d bayonet base, the two bulb types are not physically interchangeable despite sharing a similar dual-filament function.
The Saturn SL2 Center High Mount Stop Light uses PC-series miniature wedge bulbs rather than the standard brake bulbs found in the tail lamp housings.
The PC175 and PC168 bulbs both follow the T10 wedge form factor and use a printed circuit board twist-lock socket, which is a mounting interface distinct from conventional bulb sockets.
Within the Center High Mount Stop Light, the Saturn SL2 (1999 and 2002) takes the PC175, while model years 1995-1998 and 2000-2001 take the PC168, indicating the two bulb designations are not universally interchangeable across all years of this model.
Both PC175 and PC168 are rated at 12V and conform to the ANSI standard applicable in the US and Canada.
The BAY15d base on the 2057 features offset pins that establish a fixed rotational orientation in the socket, a design that prevents incorrect installation and is a defining characteristic separating it from single-filament bayonet types.
The dual-filament configuration present in both the 3157 and 2057 allows a single bulb to serve both the brake and tail light functions within the same housing, with each filament wattage corresponding to a separate circuit.