2018 Kia Optima bulb fitment varies by headlight configuration. For low beams, models with halogen headlights use 9005 bulbs, while models with LED headlights use LED lighting. High-beam fitment is LED on LED-equipped versions; models with single projector-type headlights use 9005 bulbs.
Several exterior lights also differ by configuration. Brake lights are LED with LED headlights and use 7528 bulbs with single projector-type headlights. Parking lights are LED on LED-headlight models or 2357A with single projector-type headlights. Rear tail-light fitment includes LED on LED-headlight versions, while halogen-headlight versions may use 2825 or 98; 7528 is also listed for the tail light.
- Front turn signal: 2357A
- Rear turn signal: 1156A
- Reverse light: 921
- Daytime running light and center stop: LED
- License plate: 168 or 917
- Interior: 6461 dome, 6418 glove box/trunk/vanity, and 194 or 7441 map light
Verify the installed headlight style before ordering, especially when choosing between LED and 9005 applications.