What is the low beam headlight bulb size for a 2018 BMW 640i?

The 2018 BMW 640i uses a N/A 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 BMW 640i?

The high beam bulb size for the 2018 BMW 640i is N/A.

Why are my 2018 BMW 640i headlights dim?

Dim headlights on a 2018 BMW 640i can be caused by aging halogen bulbs, which lose brightness over time, or oxidation (cloudiness) on the plastic headlight lenses. Upgrading to a N/A LED conversion kit can provide a significantly brighter and whiter light output.

Which bulb fits the 2018 BMW 640i fog light?

The 2018 BMW 640i typically does not come with factory fog lights in all trim levels. If your vehicle is equipped with them, check the manual as sizes can vary by trim.

Is the 2018 BMW 640i single or dual beam?

The 2018 BMW 640i uses a dual bulb headlight system. This means you have separate bulbs for high and low beams.

Can I install LED bulbs on my 2018 BMW 640i?

Yes, the 2018 BMW 640i comes with standard halogen bulbs from the factory, but they can be upgraded to LED. You will need a N/A LED conversion kit for the low beams.

Did the 2018 BMW 640i change headlight bulb sizes from the previous year?

Yes — the 2018 BMW 640i uses different bulb sizes than the 2017 model. The 2018 generation introduced this bulb configuration.

Is the 2018 BMW 640i the first or last year to use N/A bulbs?

The 2018 BMW 640i is the only year in the 2018 generation to use the N/A bulb for the low beam headlight.

How do I change the headlight on a 2018 BMW 640i?

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 N/A bulb counter-clockwise to remove it, then insert the new bulb and reassemble. Note: BMW 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 BMW 640i?

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 N/A 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 BMW 640i headlights?

A pair of halogen N/A 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 BMW 640i?

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 N/A position are available as direct plug-and-play replacements. Since the BMW uses CANbus monitoring, choose a CANbus-compatible LED kit to avoid dashboard errors.

The 2018 BMW 640i has a unique bulb configuration not shared with adjacent model years.

Fitment Guaranteed for 2018 BMW 640i

What Size Bulbs Does a 2018 BMW 640i 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 BMW 640i Have?

The 2018 BMW 640i utilizes a refined lighting configuration featuring 2 distinct bulb positions. It features a standard lighting system powered by a dual-bulb halogen configuration using separate low beam and high beam bulbs for precise light distribution. This model belongs to the late years of the 640i's 2012-2018 production span. Note that BMW 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 BMW 640i?

Upgrading to LED is one of the most effective ways to modernize your BMW's appearance and safety profile. We recommend starting your upgrade with the low beams, as they see the most use. Adding a matching LED kit later will complete the look and ensure consistent lighting performance. Because BMW 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.

2018 BMW 640i Bulb Size Chart

Position	Bulb Size	Shop
Reverse Light	921	Buy 921 →
Door Light	W5W	Buy W5W →

How do the 2018 BMW 640i's bulbs compare to other years?

The 2018 BMW 640i changed bulb sizes from 2017. The previous model year used a different configuration.

This bulb configuration covers the 2018 model years. ← 2017

Finding the best installation guide...

Other 640i Years

2017 2016 2015 2014 2013 2012