Toyota Tacoma Turn Signal Bulb Size

Additional Notes

• The 4157NA is the most frequently specified front turn signal bulb across the Toyota Tacoma's history, appearing in model years 2002 and 2006-2009 and 2011 and 2013-2015. It is a dual-filament T25 wedge bulb rated at 12V with a 27W high filament and 7W low filament, and its natural amber glass produces the required amber signal color without a painted or coated lens.
• The 1156 bulb serves as the front turn signal for the 1995-2000 Tacoma and as the rear turn signal for the 1995-2004 model years. Unlike the dual-filament bulbs used in later years, the 1156 is a single-filament type with a BA15s bayonet base, rated at 12V and 21W, meaning it is dedicated solely to the turn signal function rather than sharing a filament with another circuit.
• The 3157NA is the dominant rear turn signal bulb across the 2005-2015 Tacoma. It shares the same T25 wedge form factor, 12V rating, and 27W/7W dual-filament output as the 4157NA used at the front, but the two are not the same part and are not interchangeable despite their similar specifications.
• The 5702AK, a Sylvania-specific part number, appears as the front turn signal bulb in several non-consecutive model years. It is a coated variant of the ANSI 3157 bulb with a T25 wedge base, 12V, and 27W/7W dual-filament output. Its amber color comes from a surface coating rather than natural amber glass, which distinguishes it from the NA-suffix bulbs used in adjacent model years.
• The 7443 is specified for the front and rear turn signals of the 2018 and 2021-2023 Tacoma. It is a dual-filament T20 wedge bulb rated at 12V with a 21W high filament and 5W low filament. The T20 wedge base is physically distinct from the T25 base used by the 4157NA and 3157NA families, making cross-substitution between these groups impossible without modification.
• The 7440NA is specified for the front turn signal on the 2018 and 2021-2022 Tacoma. It is a single-filament T20 wedge bulb with natural amber glass, rated at 12V and 21W. Although it shares the T20 wedge base with the dual-filament 7443, the 7440NA has only one filament, so the two are not functionally interchangeable in positions that require dual-filament operation.
• The front and rear turn signal positions on the Toyota Tacoma do not consistently use the same bulb type within a given model year. For example, the 2022 front position calls for a 7440NA while the rear requires a 7443, and the 2015 front position uses a 4157NA while the rear uses a 3157NA. Treating front and rear positions as interchangeable would result in an incorrect fitment.
• Across all specified bulbs, the operating voltage is uniformly 12V, consistent with standard 12-volt automotive electrical systems. Wattage varies by bulb family: the T20 group operates at 21W or 21W/5W, while the T25 group operates at 27W/7W, reflecting a higher power draw in the larger bulb format.