Honda Civic Tail Light Bulb Size

Additional Notes

• The 2057 bulb is the tail light specification for the Honda Civic across model years 1973-1991, with the exception of 1984 and 1985. The 7440 is specified for the 2024 model year.
• The 2057 is a dual-filament bulb rated at 12V with a high-filament draw of 26.9W and a low-filament draw of 8W. This dual-filament design allows a single bulb to serve both tail light and brake light functions at different brightness levels.
• The 2057 uses a BAY15d bayonet base, which features two pins offset at different heights to ensure correct polarity orientation during installation. This base type is not interchangeable with single-contact bayonet bases.
• The 2057 is described as a brighter variant of the 1157. While the two share the BAY15d base and are physically similar, the 2057 draws more wattage on its high filament, meaning substituting one for the other affects output intensity.
• The 7440 is a single-filament wedge bulb of the T20 type, rated at 12V and 21W. Unlike the 2057, it carries no dual-filament capability, which reflects a different tail light circuit design in the 2024 Honda Civic.
• Both the 2057 and 7440 conform to ANSI standards applicable in the United States and Canada, meaning their electrical and physical specifications are governed by a standardized classification system used across the North American automotive market.
• The wedge base of the 7440 and the BAY15d bayonet base of the 2057 are physically incompatible socket types, making cross-substitution between these two bulbs impossible without socket modification.