Cadillac XT4 Turn Signal Bulb Size

Cadillac XT4 front turn signal uses a 7440NA bulb size for replacement. The chart covers 2019 to 2021 model years with corresponding bulb size specifications.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Front Turn Signal

Years	Bulb Size
2021	7440NA
2019-2020	7440NA (Without Cornering Headlamps)

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament wedge bulb (T20), natural amber glass. 12V, 21W.	7440NA

Other Locations

Additional Notes

The 7440NA is a single-filament wedge bulb following the T20 form factor, rated at 12 volts and 21 watts, and built to ANSI standards applicable in the United States and Canada.
The natural amber glass of the 7440NA produces an amber-colored output without relying on a colored lens or housing, which is a characteristic of the NA (Natural Amber) designation within the 7440 bulb family.
The Cadillac XT4 uses the 7440NA for the front turn signal across the 2019-2021 model years.
The 2019 and 2020 model years carry a "Without Cornering Headlamps" qualifier, indicating that this fitment applies specifically to vehicles not equipped with that feature, while the 2021 model year carries no such qualifier.
The standard 7440 bulb shares the same T20 wedge base and electrical ratings as the 7440NA but uses a clear glass envelope, making it a physically interchangeable but visually distinct alternative that would not replicate the amber output of the factory specification.