What Size Bulbs Does a 2015 Subaru WRX STI Use?
Correct headlight, fog light, and tail light bulb sizes. Sourced from OEM catalog data.
Installation Difficulty
Easy (Plug and Play)
Est. Replacement Cost
$15 - $40 (Halogen) / $30+ (LED)
What Lighting System Does the 2015 Subaru WRX STI Have?
The 2015 Subaru WRX STI features an extensive lighting system with 13 bulb positions. It uses factory LED technology with integrated LED headlight modules. The WRX STI has been available from 2004 to 2019, and the 2015 model falls in the mid-generation years.
Can You Put LED Bulbs in a 2015 Subaru WRX STI?
To upgrade the 2015 Subaru WRX STI headlights to LED, you will need a LED Bulb LED kit for the low beams and a 9005 LED LED kit for the high beams. Start with the low beams since they are used most often and have the biggest impact on nighttime visibility. For the fog lights, a H11 LED LED bulb provides a clean white output that pairs well with LED headlights.
How to Replace Bulbs on a 2015 Subaru WRX STI
To remove the headlight bulb, disconnect the wiring harness, then twist the bulb counter-clockwise and pull it straight out of the housing. Older model years like the 2015 WRX STI typically offer easy access to the headlight bulbs from behind the headlight assembly under the hood. Most owners can complete the swap in under 10 minutes per side. This vehicle has factory-integrated LED headlight modules. These are not user-serviceable bulbs. If your LED headlights fail, the entire headlight assembly or LED module may need to be replaced by a dealer or qualified technician. The fog lights are accessed from underneath the front bumper. You may need to remove a few plastic clips or screws from the fender liner to reach the H11 LED fog light socket.
Full Upgrade Bundle
Upgrade All 13 Positions at Once
2015 Subaru WRX STI Complete Bulb Size Chart
| Position | Bulb Size | Shop |
|---|---|---|
Low Beam | LED Bulb | Buy LED Bulb |
High Beam | 9005 LED | Buy 9005 LED |
Fog Light | H11 LED | Buy H11 LED |
Brake Light | LED Bulb | Buy LED Bulb |
Side Marker | 168 LED | Buy 168 LED |
Turn Signal Front | 7440NA LED | Buy 7440NA LED |
Turn Signal Rear | 7440NA LED | Buy 7440NA LED |
Reverse Light | 921 | Buy 921 |
Dome Light | DE3175 | Buy DE3175 |
License Plate | 168 | Buy 168 |
Map Light | DE3175 | Buy DE3175 |
Parking Light | LED Bulb | Buy LED Bulb |
Trunk Light | 168 | Buy 168 |
Want to upgrade everything at once?
Shop Complete LED Kit for 2015 Subaru WRX STIHow Long Do 2015 Subaru WRX STI Headlight Bulbs Last?
Factory LED headlights on the 2015 Subaru WRX STI are rated for approximately 25,000 to 50,000 hours of use, which translates to roughly 10 to 15 years of normal driving. LED modules rarely burn out suddenly. Instead, they gradually dim over time or develop dead zones within the LED array. At 11 years old, the original bulbs on your WRX STI are likely overdue for replacement, though LED modules may still have life left. Even if they still illuminate, reduced brightness significantly impacts nighttime safety. When one headlight burns out, replace both sides at the same time. Bulbs from the same batch age at similar rates, and mismatched brightness is distracting to oncoming drivers.
What Bulbs Are Compatible with the 2015 Subaru WRX STI?
For the high beams, the 9005 is interchangeable with HB3. Using the wrong bulb size can cause improper beam patterns that reduce your visibility and blind other drivers. It can also cause overheating inside the headlight housing, potentially warping the plastic lens or reflector. Always verify the bulb number before purchasing.
2015 Subaru WRX STI Headlight FAQ
Did Subaru WRX STI Bulb Sizes Change Over the Years?
Over its production run from 2004 to 2019, the Subaru WRX STI has seen bulb size changes in the Low Beam, Fog Light and Brake Light positions. The 2015 model uses the earlier bulb specification that was in place before the change around 2018. Always verify the exact bulb size for your specific 2015 model year using the chart above, as using the wrong size can result in poor fitment or reduced light output.