Saturn SL Back Up Light Bulb Size

The Saturn SL back up light utilizes P21W, 1156, and 2057 bulb sizes depending on the specific version of the vehicle. Information provided covers the range from 1991 through 2002.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Bulb Size by Year Range

Years	Bulb Size
1996-2002	1156
1991-1995	2057

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1156
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. Brighter variant of 1157. 12V, 26.9W/8W.	2057

Other Locations

Additional Notes

The Saturn SL back up light specifications cover model years 1991 through 2002 and reference two distinct bulb sizes: 1156 and 2057.
The 1156 bulb is an ANSI-standard single-filament type rated at 12V and 21W, fitted with a BA15s bayonet base, which accepts only a single pin and is therefore not interchangeable with dual-pin bases.
The 2057 bulb is an ANSI-standard dual-filament type with a BAY15d bayonet base, rated at 12V with filaments drawing 26.9W and 8W respectively, and is described as a brighter variant of the 1157.
The Saturn SL (1996-2002) uses the 1156 bulb for the back up light position.
The 1991-1995 model years use the 2057 bulb instead, representing a different base type and wattage profile from the later specification.
Because the BA15s base of the 1156 and the BAY15d base of the 2057 are physically distinct, the two bulbs are not interchangeable with each other despite both using a bayonet-style mount.
The BAY15d base used by the 2057 features two offset pins that lock the bulb in a fixed rotational position, a design that prevents incorrect filament alignment in dual-filament applications.
Both bulb types conform to ANSI standards applicable in the United States and Canada, indicating standardized electrical and physical tolerances across compliant manufacturers.