Audi S4 Dome Light Bulb Size

Additional Notes

• The 6411 is the sole dome light bulb size specified for the Audi S4 across all listed model years.
• The 6411 bulb follows the ANSI standard, which is the recognized specification system used in the United States and Canada for automotive lighting components.
• This bulb uses a festoon form factor, meaning it is a cylindrical lamp that mounts by pressing its end caps into spring-loaded contacts rather than using a twist or plug-in base.
• The 6411 has a 36mm length, which is the contact-to-contact span of the festoon body and determines physical fitment within the dome light housing.
• The base type is SV8.5, a designation that refers to the end-cap style and contact spacing specific to festoon bulbs of this size class.
• The 6411 operates at 12 volts, consistent with the standard electrical system voltage found in passenger vehicles.
• The bulb carries a 5-watt power rating, placing it in the low-wattage range typical of interior courtesy lighting.
• The Audi S4 (2013-2016) shares the same 6411 specification across those four consecutive model years, indicating consistent dome light housing design within that period.
• Because festoon bulbs are sized by length, substituting a festoon bulb of a different length, such as 31mm or 41mm, would result in an improper fit even if the voltage and wattage ratings matched.