For the 2018 GMC Yukon XL, the low-beam bulb depends on the factory headlight system. Models with halogen headlights use an H11 low beam, while models with HID headlights use a D3S low beam. Verify the headlight type before ordering, since these bulbs are not interchangeable.
The high beam uses a 9005 bulb. The supplied fitment data also lists a 9006 LED bulb for the fog lights.
- High beam: 9005
- Low beam: H11 with halogen headlights; D3S with HID headlights
- Fog light: 9006 LED
- Reverse light: 921
- License plate: 2825
- Vanity light: 6612F
Check the existing headlamp assembly or vehicle equipment before purchasing low-beam replacements, especially when selecting between halogen and HID applications.