Honda Insight front turn signal bulbs use 2357NA, 7440NA, or 7440 sizes, while rear turn signal bulbs use 7440NA or 7440 sizes. The replacement bulb chart covers 2000 to 2022 production years with corresponding specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 7440 bulb is the most widely used type across Honda Insight turn signal specifications, appearing in both front and rear positions across the 2000-2006 and 2010-2014 model years. It is an ANSI-standard single-filament T20 wedge bulb rated at 12V and 21W.
The 7440NA variant shares the same T20 wedge form factor, voltage, and wattage as the standard 7440 but incorporates natural amber-tinted glass. This tinting produces the amber signal color directly from the bulb rather than relying solely on a colored lens.
The 2357NA, specified for the Honda Insight front turn signal in 2021-2022, differs fundamentally from the 7440-series bulbs in both base type and filament count. It uses a BAY15d bayonet base and carries two filaments rated at 26.9W and 8W respectively, operating at 12V.
Because the 2357NA uses a BAY15d bayonet base and the 7440NA uses a T20 wedge base, these two bulb types are not physically interchangeable despite both being specified for front turn signal positions on the Insight at different model years.
The rear turn signal position uses the 7440NA for the 2019-2022 model years, while the front turn signal for those same years splits between the 7440NA (2019-2020) and the 2357NA (2021-2022), meaning front and rear positions do not share the same bulb type in 2021-2022.
The dual-filament design of the 2357NA suggests the front turn signal housing in 2021-2022 Insight models serves more than one lighting function, as the secondary 8W filament is typically associated with a parking or running light circuit alongside the primary turn signal filament.