What Size Bulbs Does a 2017 Subaru Legacy Use?
Correct headlight, fog light, and tail light bulb sizes. Sourced from OEM catalog data.
Installation Difficulty
Moderate (Dust covers often present)
Est. Replacement Cost
$50 - $150 (HID System)
What Lighting System Does the 2017 Subaru Legacy Have?
The 2017 Subaru Legacy features an extensive lighting system with 13 bulb positions. It uses factory HID/Xenon technology with D4S projector headlights. The Legacy has been available from 1990 to 2019, and the 2017 model falls in the late-generation years.
Can You Put LED Bulbs in a 2017 Subaru Legacy?
The 2017 Subaru Legacy comes equipped with factory D4S HID/Xenon headlights. These already produce significantly more light than halogen bulbs, so upgrading is generally unnecessary. When your HID bulbs burn out, replace them with OEM-spec D4S HID bulbs to maintain the correct color temperature and beam pattern. Avoid cheap aftermarket HID bulbs as they can produce incorrect beam patterns and blind oncoming drivers. Your fog lights use a H11 LED halogen bulb, which can be upgraded to LED for a whiter color match with your HID headlights.
How to Replace Bulbs on a 2017 Subaru Legacy
To remove the headlight bulb, disconnect the wiring harness, then twist the bulb counter-clockwise and pull it straight out of the housing. On the 2017 Legacy, you will likely encounter rubber dust covers behind the headlight housing. These pull off by hand or unscrew depending on the design. Allow about 15 to 20 minutes per side. HID headlights operate at high voltage. Always disconnect the battery before working on the headlight assembly. Never touch the HID ballast while the headlights are on, and handle the D4S capsule with gloves to avoid oil contamination. 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
2017 Subaru Legacy Complete Bulb Size Chart
| Position | Bulb Size | Shop |
|---|---|---|
Low Beam | HID-D4S LED | Buy HID-D4S LED |
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 | 194 | Buy 194 |
Want to upgrade everything at once?
Shop Complete LED Kit for 2017 Subaru LegacyHow Long Do 2017 Subaru Legacy Headlight Bulbs Last?
HID/Xenon headlights on the 2017 Subaru Legacy typically last 2,000 to 3,000 hours, or about 4 to 6 years of regular driving. As HID bulbs age, they shift color toward pink or purple, which is a clear sign that replacement is needed. Flickering on startup also indicates a worn bulb or failing ballast. At 9 years old, the original bulbs on your Legacy are likely overdue for replacement. 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 2017 Subaru Legacy?
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.
2017 Subaru Legacy Headlight FAQ
Did Subaru Legacy Bulb Sizes Change Over the Years?
Over its production run from 1990 to 2019, the Subaru Legacy has seen bulb size changes in the Low Beam, High Beam and Fog Light positions. The 2017 model uses the earlier bulb specification that was in place before the change around 2018. Always verify the exact bulb size for your specific 2017 model year using the chart above, as using the wrong size can result in poor fitment or reduced light output.
Other Legacy Years
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Other Vehicles That Use HID-D4S LED Bulbs
These vehicles from other makes also use a HID-D4S LED low beam bulb: