Toyota Highlander Turn Signal Bulb Size

Additional Notes

• The 7440NA is a single-filament T20 wedge bulb rated at 12V and 21W, built to the ANSI standard used in the United States and Canada. Its natural amber glass produces the orange signal color without relying on a colored lens or housing.
• The 7444NA shares the same T20 wedge form factor as the 7440NA but carries a dual filament rated at 21W and 5W. The lower-wattage filament is typically reserved for a secondary function such as a parking or daytime running light, while the higher-wattage filament handles the turn signal flash.
• The 3457NA is a dual-filament T25 wedge bulb rated at 12V, 27W, and 7W. The T25 body is physically larger than the T20, and its higher wattage output distinguishes it from the 7444NA despite both being dual-filament ANSI-standard bulbs with natural amber glass.
• The P21/5W uses a BAY15d bayonet base rather than a wedge base, making it physically incompatible with sockets designed for T20 or T25 wedge bulbs. It follows the ECE standard rather than the ANSI standard and carries a 21W/5W dual-filament rating at 12V.
• The Toyota Highlander (2001-2005) front turn signal position uses the P21/5W, while all other model years in the specifications use ANSI-standard wedge bulbs. The bayonet base of the P21/5W is not interchangeable with the wedge sockets found in later Highlander front housings.
• The front turn signal position on the Toyota Highlander uses the 7444NA for the 2014-2023 model years and the 7440NA for 2024. Although both are T20 wedge bulbs with natural amber glass at 12V, the 7444NA is dual-filament and the 7440NA is single-filament, meaning the two types are not functionally interchangeable in sockets wired for both filaments.
• The 2011-2013 front turn signal position calls for the 3457NA, a T25 wedge bulb. The T25 socket is larger than the T20 socket, so 7440NA or 7444NA bulbs intended for T20 applications would not seat correctly in a T25 housing.
• The rear turn signal position on the Toyota Highlander uses the 7440NA across all model years listed in the specifications, from 2001 through 2024, making it the single most consistently specified bulb across both positions and all years covered.