Mazda CX-3 front turn signal uses 1156NA bulb size while rear turn signal uses 7443NA or 7440NA bulb sizes. The replacement bulb size chart covers 2016 to 2021.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Mazda CX-3 front turn signal uses the 1156NA bulb across all listed model years from 2016-2021, making it the most consistent fitment in these specifications.
The 1156NA is a single-filament bulb rated at 12V and 21W, fitted with a BA15s bayonet base. The bayonet mount requires an alignment-and-lock insertion rather than a straight push, which distinguishes it physically from wedge-base bulbs.
The natural amber glass of the 1156NA produces the amber turn signal color directly from the bulb itself, rather than relying on a colored lens housing to achieve the required signal hue.
The rear turn signal of the Mazda CX-3 uses a different bulb type for the 2021 model year than for the 2016-2019 model years, representing a fitment change within the same generation.
The 2021 rear turn signal calls for the 7443NA, a dual-filament T20 wedge bulb rated at 12V with a 21W main filament and a 5W secondary filament. The presence of two filaments means the socket wiring on the 2021 model is configured to support both functions.
The 2016-2019 rear turn signal uses the 7440NA, a single-filament T20 wedge bulb rated at 12V and 21W. Although the 7440NA and 7443NA share the same T20 wedge form factor, they are not interchangeable due to the filament count difference.
Installing a 7440NA in a 2021 rear socket designed for the 7443NA would leave the secondary filament circuit without a functioning element, as the single-filament bulb has no corresponding second filament to complete that circuit.
All three bulb types in these specifications carry the ANSI standard designation applicable to the US and Canadian markets, indicating they conform to a standardized performance and dimensional classification used across North American automotive applications.