Buick LeSabre Back Up Light Bulb Size

The Buick LeSabre back up light utilizes unique bulb sizes 3057, 2456, P21W, and 1156 across various production periods. Available data covers the range from 1959 to 2005.

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
2000-2005	3057
1997-1999	2456
1991-1996	1156
1959-1987	1156

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Dual-filament wedge bulb (T25). 12V, 27W/7W.	3057
ANSI standard (US & Canada). Festoon bulb, specialty application. 12V.	2456
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1156

Other Locations

Additional Notes

The Buick LeSabre back up light specifications span model years 1959 through 2005, covering three distinct bulb types across that range.
The 1156 bulb is the most widely used type in these specifications, appearing in the Buick LeSabre from 1959 through 1992 and again in 1994 through 1991, making it the dominant fitment across the majority of model years covered.
The 1156 is a single-filament bulb rated at 12V and 21W, fitted with a BA15s bayonet base, which is a single-contact base with a 15mm collar and a single locating pin.
The 3057 is a dual-filament wedge bulb of the T25 form factor, rated at 12V with a 27W main filament and a 7W secondary filament. The Buick LeSabre uses it for back up lighting in model years 2000-2005, where only the brighter filament would be active in a single-function back up light circuit.
The 2456 is a festoon-style bulb rated at 12V and is designated for specialty applications under the ANSI standard. The Buick LeSabre uses this type for the 1997-1999 model years.
All three bulb types in these specifications conform to ANSI standards recognized in both the United States and Canada, indicating standardized sizing and electrical ratings across the North American market.
The transition from the 1156 to the 2456 between the 1992 and 1997 model years represents a change in both bulb form factor and base type, as the 1156 uses a bayonet base while the 2456 uses a festoon mounting style, meaning the two types are not interchangeable.
The subsequent transition from the 2456 to the 3057 between the 1999 and 2000 model years introduces a wedge base fitment, which differs physically from both the bayonet base of the 1156 and the festoon mounting of the 2456, making cross-substitution between these three types incompatible without a socket adapter.
The dual-filament design of the 3057 distinguishes it from the single-filament 1156, and substituting one for the other would be inadvisable even if a socket adapter were used, as the wattage ratings and filament configurations differ between the two types.
The 1156 bulb type spans the longest continuous production period in these specifications, covering model years 1959-1992, which reflects its long-standing prevalence as a standard automotive bulb in North American vehicle manufacturing throughout that era.