The Audi A5 high beam headlight uses D3S, H7, or H15 bulb sizes, while the low beam headlight requires D3S or H7 bulb sizes. The replacement chart covers 2010 through 2014 production years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
ECE standard (Europe & worldwide). Mercury-free HID (xenon) discharge bulb with PK32d-5 base and integral ignitor, for projector-type housings. 42V, 35W.
The D3S is an HID (xenon) discharge bulb operating at 42V and 35W. It carries an integrated ignitor and uses a PK32d-5 base, making it designed specifically for projector-type housings. It is mercury-free and conforms to ECE standards used across Europe and worldwide.
The H7 is a single-filament halogen bulb rated at 12V and 55W, fitted with a PX26d base. Beyond its ECE certification, it also holds approval in the United States and Japan, giving it broader regulatory acceptance than most ECE-only bulbs.
The H15 is a dual-filament halogen bulb rated at 12V with two wattage outputs: 55W for the high-beam filament and 15W for the secondary filament. It uses a PGJ23t-1 base, which is physically distinct from the PX26d base of the H7 and is not interchangeable with it.
In the Audi A5, HID-equipped trims use the D3S for both high beam and low beam functions across the 2010-2014 model years, meaning a single bulb type serves both positions in those headlamp assemblies.
Halogen-equipped A5 models from 2011-2014 use the H7 for both the high beam and low beam positions, while the 2010 model year is a notable exception: it uses the H15 for the high beam rather than the H7.
Because the 2010 A5 high beam position takes an H15 while the low beam takes an H7, the two positions in that year's halogen headlamp assembly require different bulb types and are not interchangeable with each other.
The D3S and H7 are mutually exclusive fitments on the Audi A5. The headlamp assembly type, either HID or halogen capsule, determines which bulb applies, and substituting one type for the other is not supported by the specifications.
All three bulb types listed, the D3S, H7, and H15, conform to ECE standards, indicating that the A5 headlamp system across all listed years is built around internationally standardized bulb formats rather than proprietary sizes.