What is the low beam headlight bulb size for a 2018 Audi S4?

The 2018 Audi S4 uses a LED Headlights bulb for the low beam headlights. We recommend upgrading to LED for better visibility.

What is the high beam headlight bulb size for a 2018 Audi S4?

The high beam bulb size for the 2018 Audi S4 is LED Headlights.

Why are my 2018 Audi S4 headlights dim?

Dim headlights on a 2018 Audi S4 can be caused by aging halogen bulbs, which lose brightness over time, or oxidation (cloudiness) on the plastic headlight lenses. Upgrading to a LED Headlights LED conversion kit can provide a significantly brighter and whiter light output.

Which bulb fits the 2018 Audi S4 fog light?

The 2018 Audi S4 uses a LED Fog Light bulb for the fog light position.

Is the 2018 Audi S4 single or dual beam?

The 2018 Audi S4 uses a single bulb (dual filament) headlight system. This means one bulb controls both high and low beams.

Can I install LED bulbs on my 2018 Audi S4?

Yes, the 2018 Audi S4 comes with standard halogen bulbs from the factory, but they can be upgraded to LED. You will need a LED Headlights LED conversion kit for the low beams.

Does the 2018 Audi S4 have fog lights?

Yes, the 2018 Audi S4 takes a LED Fog Light bulb for the fog light position.

Did the 2018 Audi S4 change headlight bulb sizes from the previous year?

Yes — the 2018 Audi S4 uses different bulb sizes than the 2016 model. The 2018–2019 generation introduced this bulb configuration.

How do I change the headlight on a 2018 Audi S4?

Turn off the vehicle and open the hood. Locate the headlight assembly from behind, remove the dust cover or retaining clip, disconnect the wiring harness, twist the old LED Headlights bulb counter-clockwise to remove it, then insert the new bulb and reassemble. Note: Audi vehicles use a CANbus system, so LED replacements may need an anti-flicker decoder. The whole process typically takes 10 to 30 minutes per side depending on accessibility.

Are LED headlights legal for a 2018 Audi S4?

LED bulbs used off-road or in auxiliary lights are legal everywhere. For on-road headlight use, legality varies by state. Many states allow LED retrofits as long as the beam pattern meets DOT standards. For the best legal compliance, choose a DOT-approved LED Headlights LED kit that is designed as a direct replacement and produces a proper cutoff pattern without excessive glare.

How much does it cost to replace 2018 Audi S4 headlights?

A pair of halogen LED Headlights bulbs costs $15 to $40, while LED conversion kits run $25 to $60 per pair. If you have a shop do the work, expect an additional $20 to $50 in labor per bulb. Replacing them yourself at home saves the labor cost and usually takes under 30 minutes.

What is the difference between halogen and LED for a 2018 Audi S4?

Halogen bulbs produce a warm yellow light (around 3200K), last 500 to 1000 hours, and draw more power. LED bulbs emit a brighter white light (5000-6000K), last 25,000+ hours, and use less energy. LED upgrades for the LED Headlights position are available as direct plug-and-play replacements. Since the Audi uses CANbus monitoring, choose a CANbus-compatible LED kit to avoid dashboard errors.

The 2018 Audi S4 is the first model year to use this bulb configuration (2018–2019).

Fitment Guaranteed for 2018 Audi S4

What Size Bulbs Does a 2018 Audi S4 Use?

Correct headlight, fog light, and tail light bulb sizes. Sourced from OEM catalog data.

Installation Difficulty

Hard (Tight clearances)

Est. Replacement Cost

$15 - $40 (Halogen) / $30+ (LED)

What Lighting System Does the 2018 Audi S4 Have?

When it comes to nighttime visibility, the 2018 Audi S4 relies on an arrangement of 13 specialized bulbs. It features an extensive lighting system powered by factory-integrated LED technology, which offers superior longevity and a modern cool-white appearance compared to traditional bulbs. This model belongs to the late years of the S4's 1992-2020 production span. Note that Audi vehicles typically feature a CANbus electrical monitor that checks for specific bulb resistance.

LED Flicker Warning

This vehicle is known to use a CANbus system. Installing standard LEDs may cause flickering.

Use a CANbus decoder.

Can You Put LED Bulbs in a 2018 Audi S4?

Upgrading to LED is one of the most effective ways to modernize your Audi's appearance and safety profile. Since your S4 uses a single LED Headlights bulb for both high and low beams, ensure your chosen LED kit is "dual-beam" compatible. This allows the LED circuitry to mimic the two-filament design of the original halogen bulb. Because Audi utilizes a CANbus system, standard LED bulbs may cause "bulb out" errors on your dashboard. Always opt for "Error-Free" or CANbus-ready kits which include the necessary resistors. Don't forget the LED Fog Light fog lights; switching these to LED can dramatically improve your visibility in adverse weather.

2018 Audi S4 Bulb Size Chart

Position	Bulb Size	Shop
Low Beam	LED Headlights	Buy LED Headlights →
High Beam	LED Headlights	Buy LED Headlights →
Fog Light	LED Fog Light	Buy LED Fog Light →
Brake Light	LED Bulb	Buy LED Bulb →
Side Marker	LED Bulb	Buy LED Bulb →
Turn Signal Front	LED Bulb	Buy LED Bulb →
Turn Signal Rear	LED Bulb	Buy LED Bulb →
Dome Light	LED Bulb	Buy LED Bulb →
License Plate	LED Bulb	Buy LED Bulb →
Map Light	LED Bulb	Buy LED Bulb →
Parking Light	LED Bulb	Buy LED Bulb →
Reverse Light	LED Bulb	Buy LED Bulb →
Trunk Light	LED Bulb	Buy LED Bulb →

How do the 2018 Audi S4's bulbs compare to other years?

The 2018 Audi S4 changed bulb sizes from 2016. The previous model year used a different configuration.

The 2019 model continues with the same bulb sizes.

This bulb configuration covers the 2018–2019 model years. ← 2016 2019 →

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Other S4 Years

2020 2019 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 2004 2002 2001 2000 1994 1993 1992