Audi S4 2021 Bulb Size
Bulb size chart
The 2021 Audi S4 uses a mostly LED lighting setup, and this page is designed to help you verify bulb sizes by lighting position. Whether you are checking the headlight, tail light, license plate light, or interior lamps, matching the correct location is the easiest way to confirm what fits your car.
Because trim and lighting package can vary by market and body style, the exact bulb setup on a 2021 Audi S4 may differ slightly from one vehicle to another. Use this year page as a fitment guide for the positions listed here, and compare the installed bulb or lamp assembly before ordering replacements.
For the best fitment results, always confirm your S4’s trim, lighting package, and body style before buying parts. Many exterior and interior positions on this model are LED from the factory, while some markets may use different lamp assemblies or optional equipment. If you are considering an aftermarket conversion, make sure the replacement is compatible with the vehicle’s electronics and housing design, since LED-to-LED swaps and retrofit kits are not always interchangeable. When possible, inspect the installed bulb, connector, or module before purchase so you can avoid ordering the wrong part and reduce the chance of warning lights, flicker, or poor beam pattern.
FAQ
What bulb sizes does the 2021 Audi S4 use for the headlights?
The 2021 Audi S4 page lists LED for both the high beam and low beam headlight positions. Because the headlamp design can vary by market and equipment package, verify the installed assembly before replacing any headlight-related part.
Are the front turn signal bulbs on the 2021 Audi S4 LED?
Yes, the front turn signal light bulb position is listed as LED on this page. If your vehicle has a different lighting package or market-specific setup, check the actual lamp assembly to confirm.
What about the rear turn signal bulbs on a 2021 Audi S4?
The rear turn signal light bulb position is also listed as LED. Since Audi may use different rear lamp configurations depending on trim or region, it is still smart to compare the installed unit before ordering.
Does the 2021 Audi S4 use LED brake lights and tail lights?
Yes. The brake light bulb and tail light bulb positions are listed as LED for the 2021 Audi S4. In many cases these are integrated into the lamp assembly rather than replaced as a traditional bulb.
What bulb is used for the license plate lights on the 2021 Audi S4?
The license plate light bulb position is listed as LED. If you are replacing a license plate lamp assembly, confirm the housing style and connector type as well as the bulb listing.
Are the daytime running lights on the 2021 Audi S4 LED?
Yes, the daytime running light bulb position is listed as LED. On modern Audi lighting systems, DRLs are often part of the headlamp assembly, so replacement may involve the entire unit rather than a separate bulb.
What is listed for the back up reverse light on this model year?
The back up reverse light bulb position is listed as LED. As with other exterior lighting on the 2021 Audi S4, the exact service method can depend on the lamp design and market specification.
Which interior bulbs are listed for the 2021 Audi S4?
The page lists LED for the vanity mirror light, trunk or cargo area light, dome light, map light, interior door light, and stepwell light. These positions may be part of a larger LED module rather than a simple replaceable bulb.
What bulb is used for the glove box light on the 2021 Audi S4?
The glove box light bulb is listed as 2821. This is the only position on the page with a specific non-LED bulb type shown in the available row list.
Do all 2021 Audi S4 trims use the same bulb sizes?
Not always. Trim level, lighting package, body style, and market can change the bulb or lamp setup. That is why this page is organized by lighting position instead of assuming every S4 is identical.
Should I check the installed bulb before buying replacements?
Yes. Checking the installed bulb, connector, or lamp module is the safest way to confirm fitment, especially on a 2021 Audi S4 where many positions are LED and may be integrated into the assembly.
Can I replace LED bulbs on the 2021 Audi S4 with aftermarket parts?
Sometimes, but compatibility matters. Aftermarket LED conversions may fit physically yet still cause errors, flickering, or beam pattern issues if they are not designed for the S4’s electronics and housing.