For the 2015 Nissan Titan, the supplied fitment data lists a 9005 bulb for the high-beam headlight. No low-beam bulb is specified in this data, so confirm the low-beam application on the truck before ordering a replacement. The fog lights use 880 bulbs.
Other useful exterior applications include 3457 bulbs for the front turn signals and parking lights, 921 for the reverse lights, and 3157R for the brake and tail lights. The rear turn signals use 3156, while the front and rear side markers use 194NA and 3157A, respectively. The center stop light takes a 912 bulb.
For lighting inside the Titan, the dome light uses DE3175. Map and license-plate applications may use either 168 or 917, and interior lighting includes 194 and 7441 applications. Check the existing bulb and socket when more than one size is listed.