Subaru WRX STI high beam headlight bulb size is 9005 and low beam headlight bulb size is H11. The replacement chart covers 2015 to 2020 vehicle production years with bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 9005 bulb is the specified high beam headlight type for the Subaru WRX STI across the 2015-2020 model years, making it the most consistently referenced bulb size in these specifications.
The 9005 is a single-filament halogen bulb operating at 65 watts, commonly used in high beam applications due to its focused, high-intensity output.
The H11 bulb is specified for the low beam headlight position, appearing in the 2018 and 2020 model years under the halogen capsule headlamp configuration.
The H11 is a single-filament halogen bulb rated at 55 watts, designed with an L-shaped base that is not interchangeable with other H-series connectors such as H9 or H8 without an adapter, despite sharing a similar physical housing.
The 9005 and H11 bulbs use different base types and are not interchangeable with each other, meaning the high beam and low beam sockets on the Subaru WRX STI (2015-2020) accept physically distinct bulb formats.
The 2020 model year specifies both the 9005 high beam and H11 low beam exclusively within the halogen capsule headlamp configuration, indicating that this trim or build variant uses a fully halogen-based headlight assembly.
The 2019, 2017, 2016, and 2015 model years list the 9005 for the high beam without a configuration qualifier, while the 2020 entry explicitly notes the halogen capsule headlamp condition, suggesting a distinction in headlamp system variants for that year.
The 9005 bulb is also cross-referenced under the HB3 designation in international standards, though the 9005 label is the North American market identifier used in these specifications.