Audi S8 Dome Light Bulb Size

The Audi S8 dome light uses bulb size H6W or 6411 depending on the specific version of the vehicle. Available data for the lighting components covers the period from 2001 to 2009.

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
2007-2009	H6W
2001-2003	6411

Bulb Specifications

Description	Bulb Size
ECE standard (Europe & worldwide). Single-filament signalling bulb with BAX9s base. 12V, 6W.	H6W
ANSI standard (US & Canada). Festoon bulb, 36mm length, SV8.5 base. 12V, 5W.	6411

Other Locations

Additional Notes

The Audi S8 dome light uses two distinct bulb types across its model years: the H6W for 2007-2009 and the 6411 for 2001-2003.
The H6W is an ECE-standard bulb, meaning it conforms to European and international regulations, and operates at 12 volts with a 6-watt output on a single filament.
The H6W uses a BAX9s base, which is an offset pin base design. This base type is not universally compatible with standard bayonet or festoon sockets, making direct substitution with other bulb types unlikely without a socket adapter.
The 6411 follows the ANSI standard, which governs bulb specifications in the United States and Canada. It operates at 12 volts with a 5-watt output.
The 6411 is a festoon-style bulb, meaning it is cylindrical and held in place by spring-loaded end caps rather than a twist-lock or pin base. Its length is 36mm, and it uses an SV8.5 base designation.
The SV8.5 designation on the 6411 refers to the contact cap width of 8.5mm at each end of the festoon body, a detail relevant when confirming socket fitment.
The H6W produces 6 watts while the 6411 produces 5 watts, reflecting a one-watt difference in output between the two generations of the Audi S8 dome light specification.
Because the H6W and 6411 use entirely different base types and mounting systems, the two bulbs are not interchangeable with each other, even though both operate on a 12-volt circuit.