The Buick Reatta brake light utilizes a 2057 bulb size for the specific lighting component located at the rear of the vehicle. Data for the bulb covers the range from 1988 to 1991.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Buick Reatta uses the 2057 bulb for brake lighting across all four model years covered, spanning 1988-1991.
The 2057 is a dual-filament bulb with a BAY15d bayonet base, rated at 12V with filaments drawing 26.9W and 8W respectively, conforming to ANSI standards for the US and Canadian markets.
As a dual-filament design, the 2057 serves both a high-intensity brake function and a lower-intensity running light function within a single housing.
The 2057 is a brighter variant of the 1157, sharing the same BAY15d base type, which means the two bulbs are physically compatible in terms of socket fit but are not identical in output.
The center high mount stop light on the 1988-1989 Reatta takes the 1141 bulb, while the 1990-1991 Reatta uses the 891 bulb for the same position.
The 1141 is a single-filament bulb with a BA15s bayonet base, rated at 12V and 21W, conforming to ANSI standards.
The 891 is a single-filament halogen bulb with a PGJ13 base, rated at 12V and 27W, also conforming to ANSI standards.
The 1141 and 891 bulbs use different base types, BA15s and PGJ13 respectively, making them physically non-interchangeable despite both serving the center high mount stop light position.
The shift from the 1141 to the 891 for the center high mount stop light between the 1989 and 1990 model years represents a change in both base type and bulb technology, as the 891 is a halogen type while the 1141 is a standard incandescent.