Audi TT Headlight Bulb Size

Additional Notes

• The H8 bulb is among the most frequently specified types across the Audi TT's high beam positions, covering model years 2016-2021. It follows the ECE standard and uses a PGJ19-1 base with a single filament, operating at 12V and 35W. Despite its European origin, it carries US approval as well.
• The D1S bulb appears across both high beam and low beam positions for the 2013-2015 model years, and in HID-equipped variants from 2008-2012. It is an HID xenon discharge type with a PK32d-2 base and a built-in ignitor, designed specifically for projector-type housings. It operates at 85V and 35W, which places it in a fundamentally different electrical category from halogen types.
• The H7 bulb is specified for high beam use across the 2000-2006 model years, and also appears as the halogen capsule headlamp option for both high and low beam positions from 2008-2012. It uses a PX26d base, runs at 12V and 55W, and holds approval in the US and Japan in addition to ECE markets.
• For the 2008-2012 Audi TT, both high beam and low beam positions carry dual fitment entries, one for HID headlamp variants and one for halogen capsule headlamp variants. This means the correct bulb type depends on which headlamp system the specific vehicle was built with, and the two types are not interchangeable.
• The D5S bulb is specified for low beam use in the 2019, 2021, and 2023 model years. It is a low-voltage compact HID xenon type with a PK32d-7 base, operating at 12V and 25W. Its lower operating voltage distinguishes it from the D1S and D2S types, which both require 85V.
• The 9006 bulb is specified solely for the 2023 high beam position. It follows the ANSI standard used in the US and Canada, uses a P22d base, and operates at 12V and 55W. Its base type and regulatory standard differ from the ECE-based halogen bulbs used in other model years, making it incompatible with those sockets.
• The D2S bulb is specified for low beam use in HID-equipped variants from 2000-2006. Unlike the D1S, the D2S uses a P32d-2 base and requires an external ignitor rather than an integrated one. Both operate at 85V and 35W, but their base types and ignitor configurations make them non-interchangeable despite the shared wattage.
• The H1 bulb is specified for low beam use in halogen capsule headlamp variants from 2000-2006. It uses a P14.5s base and operates at 12V and 55W. Its single-pin base design differs from the multi-pin or bayonet configurations of other halogen types in these specifications, which prevents cross-fitment between H1 and H7 sockets.