The Audi A6 fog light utilizes H7 and H3 bulb sizes depending on the specific production period for the vehicle. Available data covers the range from 1995 through 2011.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Audi A6 front fog light draws from three distinct halogen bulb types across its model years: H3, H7, and H11. All three operate at 12V and 55W, making them identical in power consumption despite their different base configurations and physical forms.
The H11 bulb uses a PGJ19-2 base and carries ECE approval for use in Europe and worldwide markets, with additional approval in the United States. It is a single-filament halogen type rated at 12V, 55W.
The H7 bulb uses a PX26d base and holds ECE approval alongside acceptance in the United States and Japan. Like the H11, it is a single-filament halogen bulb rated at 12V, 55W. The differing base types between H7 and H11 mean the two are not interchangeable.
The H3 bulb uses a PK22s base and shares the same ECE, US, and Japan approvals as the H7. Its base type differs from both H7 and H11, making it physically incompatible with sockets designed for either of those bulbs.
The Audi A6 front fog light used the H3 bulb from 1995-2004, representing the longest continuous fitment of a single bulb type across the model's fog light history in these specifications.
The H7 bulb was fitted to the Audi A6 front fog light from 2006-2008. For model years 2009-2011, both H7 and H11 are listed, indicating that two different front fog light configurations existed within those years.
From 2012-2015, the Audi A6 front fog light standardized on the H11 bulb exclusively, with no alternative fitment listed for those years.
The rear fog light on the Audi A6 uses the H21W bulb for 2012-2015. Unlike the front fog light bulbs, the H21W is a signalling bulb rated at 21W rather than 55W, reflecting its different functional role.
The H21W uses a BAY9s base, which is a bayonet-type fitting. This base type is distinct from the wedge and pin bases found on the front fog light bulbs, and the two categories are not interchangeable.
For model years where both H7 and H11 are listed for the front fog light, such as 2009-2011, selecting the incorrect bulb type would result in a fitment failure, as the PX26d base of the H7 and the PGJ19-2 base of the H11 are physically different.