Toyota Tundra Turn Signal Bulb Size

Additional Notes

• The 4157NA is the most widely used front turn signal bulb across the Toyota Tundra specifications, appearing in model years 2007-2013 and 2018-2024 with the exception of 2021. It is a dual-filament T25 wedge bulb rated at 12V with a 27W high filament and 7W low filament, conforming to ANSI standards for the US and Canadian markets. Its natural amber glass produces the required amber signal color without relying on a colored lens.
• The 3157NA shares the same T25 wedge base, voltage, and wattage ratings as the 4157NA, yet the two are not the same part number and are not listed as interchangeable within these specifications. The Toyota Tundra (2000-2006) uses the 3157NA for the front turn signal, while the rear turn signal position uses it for model years 2007-2013.
• The 2021 Toyota Tundra front turn signal departs from the 4157NA used in surrounding years, instead specifying the 7444NA. That bulb uses a smaller T20 wedge base and carries a lower wattage of 21W/5W, making it physically and electrically distinct from the T25-based 4157NA used in adjacent model years.
• For model years 2019-2022, the front turn signal fitment note specifies "With Halogen Capsule Headlamps," indicating that the 4157NA applies specifically to that headlamp configuration. The 2023-2024 rows carry no such conditional note.
• The rear turn signal position for model years 2018-2021 uses the 921, a single-filament T15 wedge bulb rated at 12V and 16W. It has no amber glass coating, which distinguishes it from the NA-suffix bulbs used in other positions on the same vehicle.
• The rear turn signal for 2005-2006 uses the 7440NA, a single-filament T20 wedge bulb rated at 21W. Although it shares the T20 base form with the 7444NA used at the front in 2021, the 7440NA is single-filament while the 7444NA is dual-filament, and the two serve different positions and model years.
• The rear turn signal specifications for 2000-2004 involve three distinct bulb types across five years. The 2456 festoon bulb with a specialty application base was used in 2000-2002, the 2356 with a BAY15d bayonet base replaced it in 2003-2004, and neither base type is shared with any other bulb listed in these specifications.
• All bulbs listed across both turn signal positions conform to ANSI standards applicable to the US and Canadian markets. The NA suffix present on the 4157NA, 3157NA, 7444NA, and 7440NA designates natural amber glass, which is an integral part of the bulb construction rather than a lens or coating applied externally.