The Subaru Forester side marker requires a 12961 bulb size for proper installation and function within the lighting assembly. Data for the specified component covers the range from 2017 to 2024.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 168 bulb is the most widely used size across the Subaru Forester's side marker specifications. It is an ANSI-standard miniature wedge bulb of the T10 type, rated at 12V and 4.9W, and it serves as the front side marker across model years 2003-2024.
The low wattage of the 168 bulb at 4.9W places it in the category of low-draw indicator lighting, typical for side marker applications where continuous illumination is required without significant electrical load.
The Subaru Forester (1998-2002) used dual-filament bulbs for the front side marker rather than the single-filament 168 type found in later years. Dual-filament bulbs carry two separate wattage ratings, one for each filament, and are generally associated with combined stop and tail or marker and turn functions.
The 1157NA and 1034NA bulbs share the same BAY15d bayonet base and natural amber glass construction. Both are rated at 12V with a 21W/5W dual-filament configuration, and the 1034NA is classified as a variant of the 1157 type.
Despite their functional and physical similarities, the 1157NA and 1034NA are not listed interchangeably across all years. The 1034NA appears in the 1998 and 2001 model years, while the 1157NA is specified for 1999, 2000, and 2002.
The natural amber glass of the 1157NA and 1034NA bulbs produces an amber color output from the bulb itself, without relying on a colored lens to achieve the required marker hue.
The rear side marker on the Subaru Forester uses the 7443 bulb for model years 2009-2015, which is a dual-filament T20 wedge type rated at 12V and 21W/5W. The T20 wedge form factor is physically larger than the T10 used by the 168 bulb, making the two types non-interchangeable.
The rear side marker specification shifts from the 7443 to the 168 bulb between the 2015 and 2017 model years. Because these two bulbs differ in both base type and wattage, a direct substitution between them is not compatible.
The 7443 is a dual-filament bulb, whereas the 168 is a single-filament type. Installing a single-filament bulb in a socket designed for a dual-filament application, or vice versa, would result in incorrect function or a non-fitting installation.
All bulb sizes listed across both the front and rear side marker specifications conform to ANSI standards applicable to the United States and Canada.