Audi A4 2003 Bulb Size
Bulb size chart
This 2003 Audi A4 bulb size guide helps you verify the correct bulbs by lighting position, so you can match the right fit before you buy. Because the A4 was offered with different trims, body styles, and lighting packages, the bulb used in one area may not be the same on every car.
Use this page to check common exterior and interior bulb locations such as headlights, turn signals, brake lights, license plate lights, dome lights, and cargo-area lamps. Matching the bulb to the exact position is the easiest way to avoid ordering the wrong part for your 2003 Audi A4.
For the best fitment results, always compare your vehicle’s trim and equipment with the bulb chart before ordering. Halogen and HID setups use different low-beam bulbs, and some lighting positions can vary between sedan, wagon, and Cabriolet models, as well as by market or lighting package. If your A4 has been converted to LED aftermarket bulbs, the size may still match, but brightness, polarity, heat management, and warning messages can differ from the original halogen setup. When possible, remove the installed bulb and check the base number or shape before purchase, especially for exterior lights and any cabin bulb that may have been replaced previously.
FAQ
What is the purpose of this 2003 Audi A4 bulb size page?
It helps you identify the correct bulb size by lighting position, such as low beam, high beam, brake light, or license plate light. That makes it easier to confirm the right replacement for your exact 2003 Audi A4 setup.
Do all 2003 Audi A4 models use the same bulbs?
No. Trim level, body style, and lighting package can change the bulb type. Cabriolet models, HID-equipped cars, and halogen-equipped cars may use different bulbs in the same location.
What low beam bulb does the base 2003 Audi A4 with halogen headlights use?
The base model with halogen headlights uses H7 bulbs for the low beam. Always confirm the headlamp type before ordering, since HID cars use a different bulb.
What low beam bulb does the base 2003 Audi A4 with HID headlights use?
The base model with HID headlights uses D1S for the low beam. This is not interchangeable with the halogen H7 setup.
What low beam bulb does the Cabriolet with HID headlights use?
The Cabriolet with HID headlights uses D2S for the low beam. That differs from the base sedan/wagon HID low beam bulb.
What high beam bulb does the base 2003 Audi A4 use?
The base 2003 Audi A4 uses H7 bulbs for the high beam. If your car has been modified, check the installed bulb before buying replacements.
What bulb is used for the front turn signal on this Audi A4?
The front outer turn signal uses 2827, and the front inner turn signal uses 3457A. These are separate locations, so it is important to check which socket you are replacing.
What bulb is used for the rear turn signal?
The rear turn signal bulb is 7507. This is one of the most common exterior bulbs to verify by position before purchase.
What bulb sizes are used for the parking light and daytime running light?
Both the parking light and daytime running light use 2825 or 98 on this page. If your car has a different market-specific lighting setup, confirm the installed bulb first.
What bulb is used for the license plate light?
The license plate light uses 6418. This same bulb number also appears in several interior and courtesy light positions on this A4.
What bulb does the dome light use?
The dome light uses 6411 or 6428. These are common interior bulb sizes, but the exact fit can depend on the housing and previous replacement parts.
What bulb is used for the back-up reverse light?
The back-up reverse light uses 7506. If one reverse light is out, it is often a good idea to replace both sides at the same time.
What bulb is listed for the brake light on the base model?
The base model brake light bulb is 7528. The Cabriolet uses 7225 for the brake light, so body style matters here.
What bulb is used for the tail light on the 2003 Audi A4?
The tail light bulb is 7225. This bulb number is also listed for the Cabriolet brake light, so check the exact lamp position on your vehicle.
Are LED bulbs listed for any positions on this page?
Yes. The center high mount stop light is listed as LED, and the front fog light position shows H11 LED or H16 LED. If you are converting to LED, make sure the bulb base and fitment match your housing.