GMC Savana outer tail light and tail light assemblies utilize bulb sizes 3157 and 2057, with the outer tail light requiring the 3157 bulb size. The replacement chart contains vehicle production years and bulb size specifications spanning from 1996 to 2024.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The GMC Savana outer tail light uses the 3157 bulb for model years 2003-2024, representing the majority of the vehicle's production span covered in these specifications.
The 3157 is a dual-filament T25 wedge bulb rated at 12V with a high filament draw of 27W and a low filament draw of 7W, conforming to ANSI standards recognized in both the United States and Canada.
The dual-filament design of the 3157 allows a single bulb to serve more than one lighting function, typically combining stop and tail light operation within one housing.
For the 1996-2002 GMC Savana, the outer tail light position calls for the 2057 bulb rather than the 3157.
The 2057 is also a dual-filament bulb, rated at 12V with filament draws of 26.9W and 8W, and it uses a BAY15d bayonet base rather than the wedge base found on the 3157.
Because the 3157 uses a wedge base and the 2057 uses a BAY15d bayonet base, the two bulb types are not physically interchangeable despite their similar wattage ratings.
The 2057 is classified as a brighter variant of the 1157, sharing the same BAY15d bayonet base but producing greater light output at the high filament.
Both the 3157 and 2057 conform to ANSI standards, meaning their electrical and physical characteristics are governed by a standardized specification applicable across the US and Canadian markets.
The transition from the 2057 to the 3157 in the Savana outer tail light position occurred between the 2002 and 2003 model years according to these specifications.