Oldsmobile Achieva Back Up Light Bulb Size

The Oldsmobile Achieva back up light utilizes bulb sizes 1156 and 2057 according to the provided specifications. Data for the bulb sizes covers the range from 1992 to 1998.

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
1995-1998	1156
1993-1994	2057
1992	1156

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 1156 bulb is an ANSI-standard single-filament bulb rated at 12V and 21W, fitted with a BA15s bayonet base. Its single filament means it serves one lighting function only, which in this context is the reverse light.
The 2057 bulb is an ANSI-standard dual-filament bulb rated at 12V with a high filament draw of 26.9W and a low filament draw of 8W. It uses a BAY15d bayonet base, which has two offset locating pins to prevent incorrect insertion.
The BA15s base on the 1156 and the BAY15d base on the 2057 are physically incompatible with each other. The pin offset on the BAY15d base means a 2057 bulb cannot seat correctly in a BA15s socket, and vice versa.
The Oldsmobile Achieva used the 1156 bulb for its back up light across the 1995-1998 model years.
The 1993-1994 Achieva used the 2057 bulb instead, representing a different socket configuration from the later production years.
The 1992 Achieva used the 1156 bulb, the same type as the 1995-1998 models, though the 1993-1994 models used a different bulb type in between.
The 2057 is noted as a brighter variant of the 1157 bulb. Despite the higher wattage output, its dual-filament design and BAY15d base make it a distinct part from the single-filament 1156 used in other Achieva model years.