Porsche 928 License Plate Bulb Size

The Porsche 928 license plate light requires a DE3423 bulb size for the rear illumination system. Available data covers the production span from 1978 through 1995 for the specified vehicle.

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
1993-1995	DE3423	Check Price
1978-1991	DE3423	Check Price

Bulb Specifications

Description	Type	Shop
ANSI standard (US & Canada). Festoon bulb, 41mm length, end-cap contacts. 12V.	DE3423	Check Price

Other Locations

Additional Notes

The Porsche 928 uses the DE3423 bulb for the license plate position across all listed model years, spanning 1978-1995.
The DE3423 is classified as a festoon bulb, meaning it is cylindrical in shape and seats between two end-cap contacts rather than fitting into a socket with a base pin or bayonet mount.
The DE3423 carries an ANSI designation, indicating it conforms to a standardized specification recognized in both the United States and Canada.
The bulb has a length of 41mm, which is the critical fitment factor for festoon-style housings, as the end caps must bridge the contact points within the fixture.
Operating voltage for the DE3423 is rated at 12V, consistent with the standard electrical system voltage found in passenger vehicles of this type.
Because the DE3423 designation is consistent across all 17 listed model years of the Porsche 928, no year-specific fitment variations exist within this position for the listed range.
Festoon bulbs of the same length are sometimes cross-compatible across different vehicle makes and models, though the 41mm length must match precisely for the end caps to maintain proper contact within the housing.