Oldsmobile Cutlass Back Up Light Bulb Size

The Oldsmobile Cutlass back up light utilizes 1156, 3057, and P21W bulb sizes depending on the specific production version. Available data for the bulb sizes covers the range from 1961 to 1999.

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
1997-1999	3057
1961-1981	1156

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Dual-filament wedge bulb (T25). 12V, 27W/7W.	3057
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1156

Other Locations

Additional Notes

The Oldsmobile Cutlass back up light specifications cover model years 1961-1999, with two distinct bulb types used across that span.
The 1156 bulb is the more widely used of the two types, appearing in the Cutlass across model years 1961-1981.
The 1156 is a single-filament bulb operating at 12V with a 21W output, fitted with a BA15s bayonet base, and is recognized under ANSI standards in both the US and Canada.
A BA15s bayonet base uses a single contact pin, which means it is not interchangeable with dual-pin bayonet base bulbs without a socket modification.
The Oldsmobile Cutlass (1997-1999) uses the 3057 bulb for the back up light position.
The 3057 is a dual-filament wedge bulb of the T25 type, rated at 12V with a 27W high filament and a 7W low filament, also conforming to ANSI standards in the US and Canada.
Because the 3057 is a dual-filament wedge type and the 1156 uses a BA15s bayonet base, the two bulb types are not interchangeable with each other.
The wedge base of the 3057 is held in place by socket tension rather than a twist-lock or pin mechanism, which differs fundamentally from the bayonet retention system of the 1156.