Audi S4 License Plate Bulb Size

The Audi S4 license plate light requires bulb size DE3423 or 3893 depending on the specific vehicle configuration. Available data covers the range from 1992 through 2012.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Bulb Size by Year Range

Years	Bulb Type	Shop
2007-2012	DE3423	Check Price
2000	DE3423	Check Price
1992-1994	3893	Check Price

Bulb Specifications

Description	Type	Shop
ANSI standard (US & Canada). Festoon bulb, 41mm length, end-cap contacts. 12V.	DE3423	Check Price
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base, specialty application. 12V.	3893	Check Price

Other Locations

Additional Notes

The Audi S4 license plate position uses two distinct bulb types across its model years: the DE3423 and the 3893, both conforming to ANSI standards applicable in the US and Canada.
Both bulb types operate at 12 volts, which is consistent with standard automotive electrical systems.
The DE3423 is a festoon-type bulb measuring 41mm in length and makes contact through end-cap terminals at each end of the housing.
The 3893 is a dual-filament bulb fitted with a BAY15d bayonet base, a configuration typically associated with specialty automotive applications.
The Audi S4 (2007-2012) uses the DE3423 festoon bulb for the license plate position, with the same specification also applying to the 2000 model year.
The 3893 bayonet-base bulb is specified for the 1992-1994 model years, representing a physically and electrically distinct fitment from the DE3423 used in later years.
The end-cap contact design of the DE3423 is incompatible with the BAY15d bayonet socket required by the 3893, meaning the two bulb types are not interchangeable despite sharing the same 12-volt rating.
The dual-filament construction of the 3893 differs fundamentally from the single-element festoon design of the DE3423, further distinguishing the two fitments.