Buick Riviera Back Up Light Bulb Size

The Buick Riviera back up light utilizes 3057, 1156, and P21W bulb sizes depending on the specific production period for the vehicle. Available information spans a total range from 1963 through 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
1995-1999	3057
1963-1993	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 Buick Riviera back up light specifications cover model years 1963-1999, with two distinct bulb types used across that span.
The 1156 bulb is the predominant fitment, specified for the Buick Riviera across model years 1963-1993.
The 1156 is a single-filament bulb rated at 12V and 21W, fitted with a BA15s bayonet base, and meets ANSI standards for the US and Canadian markets.
A BA15s bayonet base uses a single contact pin, which means it is not interchangeable with dual-pin bayonet variants without a socket adapter or replacement.
Model years 1995-1999 of the Buick Riviera use the 3057 bulb instead, representing a change in back up light fitment from the earlier 1156 specification.
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, and also carries ANSI certification for US and Canadian markets.
Because the 3057 uses a wedge base and the 1156 uses a BA15s bayonet base, the two bulb types are physically incompatible and cannot be substituted for one another without a corresponding socket change.
Although the 3057 is a dual-filament bulb, its use in a back up light application typically engages only one filament, as back up lights are single-intensity functions.