Buick Reatta front turn signal bulbs measure 890 in size, while rear turn signal bulbs measure 2057, with each bulb type serving distinct lighting functions on the vehicle. The replacement chart covers 1988 to 1991 production years and details bulb size specifications for turn signal applications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Buick Reatta uses two distinct bulb types across its front and rear turn signal positions for all four model years covered, 1988-1991.
The 890 bulb is a single-filament halogen unit operating at 12V and 27W, fitted with a PG13 base, and conforming to ANSI standards applicable in both the United States and Canada.
The front turn signal position on the Buick Reatta calls for the 890 bulb across all model years, 1988-1991, without variation.
The 2057 bulb is a dual-filament unit with a BAY15d bayonet base, rated at 12V with a dual-wattage output of 26.9W and 8W, also conforming to ANSI standards for the US and Canadian markets.
The rear turn signal position uses the 2057 bulb across all model years, 1988-1991, without variation.
The dual-filament design of the 2057 allows it to serve two lighting functions from a single bulb, with the higher wattage filament typically handling the turn signal function and the lower wattage filament handling a secondary function such as running or parking light duty.
The 2057 is a brighter variant of the 1157 bulb. While both share the BAY15d bayonet base and are physically interchangeable in many housings, the 2057 produces greater output on its high-filament circuit.
The PG13 base of the 890 bulb is a plastic grooved base type, which is not interchangeable with standard wedge or bayonet base sockets, making socket compatibility a relevant consideration during replacement.