For the 2015 Mazda Mazda3, headlight bulb fitment depends on the lighting configuration. The low beam uses either D4S or H11, while the high beam uses either D4S or 9005. Verify whether the vehicle is equipped with the applicable headlight setup before ordering. The daytime running light also uses a 9005 bulb.
The fog light fitment is H11 LED. Front turn signals use 7440A bulbs, and rear turn signals use 7440A as well. Reverse light fitment varies by body style: hatchbacks use 7440, while sedans use 921.
Front side marker fitment depends on the headlights: models with halogen headlights use 2827, while models with HID headlights use 2825. Brake and tail lights use 7443R, and the rear side marker uses 7443A. The license plate light uses 2825, parking lights use 2827, and both dome and map lights use DE3175.