The Audi A4 side marker requires a bulb with the specific 12961 size for proper installation and function within the lighting assembly. Data for the required component covers the period from 1996 through 2009.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 2825 bulb, used in the front side marker position of the Audi A4 for model years 2006-2012 with halogen headlamps, is a miniature wedge-type bulb conforming to the T10 form factor with a W2.1x9.5d base, rated at 12V and 5W.
The 3457NA bulb, fitted to the front side marker position on the Audi A4 for model years 1996-2005, is a dual-filament wedge bulb in the T25 form factor with natural amber glass, rated at 12V and 27W/7W across its two filaments.
The natural amber glass of the 3457NA means the bulb produces an amber output without relying on a colored lens, which is a relevant fitment consideration when replacing it with a clear-glass alternative.
The dual-filament construction of the 3457NA distinguishes it from the single-filament 2825 used in later model years, making the two bulbs functionally incompatible as direct substitutes despite both occupying the front side marker position.
The front side marker specification for 2006-2012 carries a halogen headlamp condition, indicating the 2825 bulb applies specifically to that headlamp configuration.
The 921 bulb, used in the rear side marker position of the Audi A4 for model years 2009-2012 with halogen tail lamps, is a T15 wedge bulb rated at 12V and 16W.
The rear side marker position of the Audi A4 uses three distinct bulb sizes across the 1996-2012 model range: the 7528 for 1996-2005, the 7506 for 2006-2008, and the 921 for 2009-2012.
The rear side marker specification for 2009-2012 carries a halogen tail lamp condition, indicating the 921 bulb applies specifically to that lamp configuration.
The front and rear side marker positions of the Audi A4 do not share a common bulb size in any model year covered by these specifications, reflecting differing wattage and socket requirements between the two positions.
All bulb sizes listed in these specifications conform to ANSI standards applicable in the United States and Canada.