Subaru Impreza Turn Signal Bulb Size

Additional Notes

• The 1156 bulb is the most widely used type across the Subaru Impreza turn signal specifications, appearing in the front inner, front, and rear turn signal positions for model years 1993-2001. It is a single-filament bulb with a BA15s bayonet base, rated at 12V and 21W under the ANSI standard.
• The T20 wedge bulb family, which includes the 7440NA, 7443NA, and 7444NA types, covers all front and rear turn signal positions on the Subaru Impreza for model years 2015-2024. All three share a 12V rating and a natural amber glass envelope, which produces the amber signal color without the need for an amber-tinted lens.
• The 7444NA and 7443NA are dual-filament T20 bulbs rated at 21W and 5W respectively for their two circuits, while the 7440NA is a single-filament T20 rated at 21W. Despite sharing the same T20 form factor and voltage rating, these types are not interchangeable due to differences in filament count and pin configuration.
• The front turn signal position uses the 7444NA for 2019 and 2024, the 7443NA for 2017-2018, and the 7440NA for 2015-2016, indicating that the dual-filament types serve the front position while the single-filament 7440NA serves the rear across 2015-2024.
• The 194 bulb is a miniature T10 wedge type rated at 12V and 3.78W, used exclusively in the front outer turn signal position on the Impreza for model years 1993-2001. Its significantly lower wattage compared to the 1156 reflects its role in a smaller, secondary signal position rather than a primary turn signal housing.
• The front inner and front outer turn signal positions are distinct fitments found only in the 1993-2001 model years, with each requiring a different bulb type. Installing a 1156 in place of a 194, or vice versa, would be an incorrect fitment due to the difference in base type and power draw.
• All bulb types listed across the specifications conform to ANSI standards applicable in the United States and Canada, meaning they share a common regulatory framework for voltage, wattage, and photometric output within those markets.
• The BA15s bayonet base of the 1156 is mechanically distinct from the wedge base of the T10 and T20 bulb families, making cross-substitution between the 1156 and any of the T20 variants physically impossible without modification to the socket.