Audi S3 Headlight Bulb Size

Audi S3 high beam headlight bulbs use H8, D5S, or D3S sizes, while low beam headlights require D5S, D3S, or H15 bulbs as replacement options. The chart covers 2015 through 2020 model 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.

High Beam Headlight

Years	Bulb Size
2020	H8
2019	H8 (Halogen, Gas discharge headlamp (D5/D7 system))
2019	D5S (With HID Headlamps)
2017-2018	H8
2016	H8 (For Vehicle With Xenon Headlights)
2016	D3S (With HID Headlamps)
2015	H8 (For Vehicle With Xenon Headlights)
	H15 (For Vehicle Without Xenon Headlights)
	D3S (With HID Headlamps)

Low Beam Headlight

Years	Bulb Size
2019	D5S (With HID Headlamps)
2016	D3S (With HID Headlamps)
2015	H15 (For Vehicle Without Xenon Headlights)
2015	D3S (With HID Headlamps)

Bulb Specifications

Description	Bulb Size
ECE standard (Europe & worldwide). Single-filament halogen bulb with PGJ19-1 base. Also approved in the US. 12V, 35W.	H8
ECE standard (Europe & worldwide). HID (xenon) discharge bulb with PK32d-7 base, low-voltage compact type. 12V, 25W.	D5S
ECE standard (Europe & worldwide). Mercury-free HID (xenon) discharge bulb with PK32d-5 base and integral ignitor, for projector-type housings. 42V, 35W.	D3S
ECE standard (Europe & worldwide). Dual-filament halogen bulb with PGJ23t-1 base. 12V, 55W/15W.	H15

Other Locations

Additional Notes

The H8 bulb is the most frequently specified high beam type across the Audi S3 data, appearing in the 2017-2020 model years as well as in conditional fitments for 2015 and 2016. The H8 is a halogen bulb operating at 35 watts with a PGJ19-1 base, belonging to the H-series single-filament family.
The D3S and D5S are high-intensity discharge (HID) bulb types. The D3S uses a mercury-free gas discharge formula and operates at approximately 35 watts with a high-voltage ignition requirement, while the D5S is similarly mercury-free but designed for specific projector-style HID systems. Both require a compatible ballast to function.
The H15 bulb is a dual-filament halogen type with a PGJ23t-1 base, capable of serving both high beam and daytime running light functions within a single unit. In the 2015 Audi S3, it is specified for both the high beam and low beam positions on vehicles without Xenon headlights.
For the 2015-2016 Audi S3, high beam fitment depends on the headlight system installed. Vehicles with HID headlamps use the D3S, while those with Xenon headlights use the H8. Vehicles without Xenon headlights use the H15.
The 2019 Audi S3 introduces a split between D5S and H8 fitments for the high beam, where the D5S applies to vehicles with HID headlamps and the H8 applies to halogen or gas discharge headlamp systems using the D5/D7 platform.
The D3S is specified for the low beam position on the 2015-2016 Audi S3 in HID-equipped vehicles, indicating that both beam functions on those trims rely on the same HID bulb family, though housed in separate projector units.
The H8 and H15 are not interchangeable despite both being halogen types. They differ in base configuration, wattage, and filament count, meaning a socket designed for one will not physically or electrically accept the other.
HID bulb types such as the D3S and D5S are similarly not interchangeable with each other. The D5S uses a different base and igniter design than the D3S, and substituting one for the other is not supported by the specifications.