The Kia Forte Koup brake light uses a 2357 bulb size for the specific lighting component located at the rear of the vehicle. Data for the specified bulb covers the range from 2010 to 2016.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 2357 bulb is the sole brake light type across all Kia Forte Koup model years in the specifications, covering 2010-2016.
The 2357 is a dual-filament bulb rated at 12V with a high filament draw of 26.9W and a low filament draw of 8W, mounted on a BAY15d bayonet base.
As a dual-filament design, the 2357 serves both a steady brake function and a lower-intensity running light function within a single housing.
The 2357 is classified as a brighter variant of the 1157 bulb under the ANSI standard, meaning the two types are not directly interchangeable despite sharing the same base type.
The Kia Forte Koup (2014-2016) carries a fitment note specifying the 2357 applies only to vehicles equipped with Halogen Capsule Headlamps, indicating a trim-level dependency for that position.
The center high mount stop light on the Kia Forte Koup shifted from the 921 bulb (2010-2013) to the P21W bulb (2014-2016), representing a change in both bulb standard and base type across the production run.
The 921 is a single-filament wedge-base bulb (T15 format) rated at 12V and 16W, conforming to the ANSI standard used in North American markets.
The P21W is a single-filament bulb rated at 12V and 21W, conforming to the ECE standard, and uses a BA15s bayonet base rather than the wedge base of the 921, making the two types physically incompatible without an adapter.
The BA15s base of the P21W and the BAY15d base of the 2357 are both bayonet-style but differ in pin configuration, with the BAY15d using offset pins to prevent incorrect single-filament bulb installation in a dual-filament socket.