For the 2011 Kia Optima, the high-beam headlight uses an H1 bulb. Low-beam fitment depends on the headlight system: models with halogen headlights use H11B, while models with HID headlights use D1S. Confirm the headlight type before ordering.
Lighting elsewhere also varies with the headlight configuration. With halogen headlights, the brake and tail lights use 1157R bulbs. With HID headlights, those functions use integrated LED lighting instead. The front turn signal and parking light use 2357A, while the rear turn signal uses 1156. Reverse lights use 921, and the center stop light is LED.
For other replacements, the front and rear side markers use 168NA. The license plate light may use 168 or 917. Compare the original dome bulb before choosing between 6461 and 64113; map light options are 194 and 7441, and the trunk light uses 6418.