What is the low beam headlight bulb size for a 2018 GMC Terrain?

The 2018 GMC Terrain uses a HID-D5S LED 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 GMC Terrain?

The high beam bulb size for the 2018 GMC Terrain is HID-D5S LED.

Why are my 2018 GMC Terrain headlights dim?

Dim headlights on a 2018 GMC Terrain can be caused by aging halogen bulbs, which lose brightness over time, or oxidation (cloudiness) on the plastic headlight lenses. Upgrading to a HID-D5S LED LED conversion kit can provide a significantly brighter and whiter light output.

Which bulb fits the 2018 GMC Terrain fog light?

The 2018 GMC Terrain uses a H11 LED bulb for the fog light position.

Is the 2018 GMC Terrain single or dual beam?

The 2018 GMC Terrain 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 GMC Terrain?

Yes, the 2018 GMC Terrain comes with standard halogen bulbs from the factory, but they can be upgraded to LED. You will need a HID-D5S LED LED conversion kit for the low beams.

Does the 2018 GMC Terrain have fog lights?

Yes, the 2018 GMC Terrain takes a H11 LED bulb for the fog light position.

How do I change the headlight on a 2018 GMC Terrain?

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 HID-D5S LED bulb counter-clockwise to remove it, then insert the new bulb and reassemble. The whole process typically takes 10 to 30 minutes per side depending on accessibility.

Are LED headlights legal for a 2018 GMC Terrain?

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 HID-D5S LED 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 GMC Terrain headlights?

A pair of halogen HID-D5S LED 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 GMC Terrain?

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 HID-D5S LED position are available as direct plug-and-play replacements.

Fitment Guaranteed for 2018 GMC Terrain

What Size Bulbs Does a 2018 GMC Terrain Use?

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

Installation Difficulty

Moderate (Dust covers often present)

Est. Replacement Cost

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

What Lighting System Does the 2018 GMC Terrain Have?

Owners of the 2018 GMC Terrain will find a total of 11 lighting elements throughout the vehicle's exterior. It features an extensive lighting system powered by a halogen-based setup where a single HID-D5S LED dual-filament bulb handles both low and high beam duties within the same reflector. This model belongs to the late years of the Terrain's 2010-2019 production span.

Can You Put LED Bulbs in a 2018 GMC Terrain?

For a GMC built for the road and trail, LED upgrades provide the high-contrast lighting needed for better obstacle detection. Since your Terrain uses a single HID-D5S LED 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. Don't forget the H11 LED fog lights; switching these to LED can dramatically improve your visibility in adverse weather.

2018 GMC Terrain Bulb Size Chart

Position	Bulb Size	Shop
Low Beam	HID-D5S LED	Buy HID-D5S LED →
High Beam	HID-D5S LED	Buy HID-D5S LED →
Fog Light	H11 LED	Buy H11 LED →
Brake Light	LED Bulb	Buy LED Bulb →
Turn Signal Front	7444NA	Buy 7444NA →
Side Marker	LED Bulb	Buy LED Bulb →
Turn Signal Rear	7440 LED	Buy 7440 LED →
Reverse Light	921	Buy 921 →
License Plate	2825	Buy 2825 →
Parking Light	7444NA	Buy 7444NA →
Trunk Light	LED Light	Buy LED Light →