Subaru WRX front turn signal bulbs use 7444NA or 7440NA sizes, while rear turn signal bulbs use 7440NA size. The chart covers 2018 to 2023 for replacement bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 7440NA and 7444NA are both T20 wedge-type bulbs operating at 12 volts, sharing the same physical base form factor within the ANSI standard recognized in the US and Canada.
The 7440NA is a single-filament bulb rated at 21W, while the 7444NA is a dual-filament bulb rated at 21W/5W, meaning the two types serve different electrical functions despite their similar housings.
Both bulb types feature natural amber glass, which produces the amber turn signal color directly from the glass envelope rather than relying on a colored lens or coating.
The rear turn signal position on the Subaru WRX uses the 7440NA across all listed model years from 2018-2023.
The front turn signal position uses the 7440NA for model years 2018-2021, then transitions to the 7444NA for 2022-2023.
The 7440NA and 7444NA are not interchangeable. Installing a 7440NA in a socket designed for a 7444NA would result in the loss of the secondary 5W filament circuit, and the reverse substitution may cause electrical or fitment conflicts.