Audi 5000 License Plate Bulb Size

The Audi 5000 license plate light uses 3893 and 1816 bulb sizes for the rear illumination system. Data for the lighting components covers the period from 1978 through 1987.

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 Size
1980-1987	3893
1978-1979	1816

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base, specialty application. 12V.	3893
ANSI standard (US & Canada). Miniature wedge bulb (T3.25). 12V, 4W.	1816

Other Locations

Additional Notes

The Audi 5000 uses two distinct license plate bulb types across its production run, with the 3893 fitted to the 1980-1987 model years and the 1816 fitted to the 1978-1979 model years.
The 3893 is the more widely used of the two bulbs in these specifications, covering eight consecutive model years of the Audi 5000.
The 3893 bulb follows the ANSI standard recognized in both the United States and Canada, and operates on a 12-volt system.
A defining characteristic of the 3893 is its dual-filament design, which is atypical for a license plate application, as most license plate bulbs use a single filament.
The 3893 uses a BAY15d bayonet base, a two-pin offset bayonet mount that mechanically prevents incorrect single-filament substitutes from seating properly, making filament count a critical fitment consideration.
The 1816 is a T3.25 miniature wedge bulb, where T3.25 denotes a tubular glass envelope measuring roughly 3.25 eighths of an inch in width, a common sizing convention in ANSI miniature bulb nomenclature.
The 1816 operates at 12 volts with a rated power draw of 4 watts, placing it in the low-wattage range standard for license plate illumination.
The wedge base of the 1816 and the BAY15d bayonet base of the 3893 are physically incompatible, so the two bulb types are not interchangeable between the 1979 and 1980 model years of the Audi 5000.