Buick Envision front turn signal bulbs use 7444NA or 7443NA sizes, while rear turn signal bulbs use 7444NA or 7440NA sizes. The replacement bulb size chart covers 2016 through 2023 model years.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 7444NA and 7443NA bulbs are both dual-filament T20 wedge types rated at 12V with a 21W high filament and a 5W low filament, while the 7440NA is a single-filament T20 wedge rated at 12V and 21W. All three follow the ANSI standard applicable in the United States and Canada.
The natural amber glass construction of the NA-suffix bulbs produces an amber output without the use of an amber lens or colored coating, which is the defining characteristic that separates them from their clear-glass counterparts in the same T20 family.
The dual-filament design of the 7444NA and 7443NA allows a single bulb to serve two lighting functions simultaneously, typically a brighter turn signal function on the high filament and a lower-intensity parking or position light function on the low filament.
The Buick Envision front turn signal position uses a dual-filament bulb across all listed years, whereas the rear turn signal position uses the single-filament 7440NA for 2016-2020 and switches to the dual-filament 7444NA for 2023.
The 7444NA and 7443NA share identical voltage, wattage, filament count, glass type, and base configuration. The distinction between the two designations is a manufacturer-level classification, and substituting one for the other in the front turn signal position carries a fitment risk that the specifications reflect by listing them separately across different model years.
The front turn signal of the Envision specifies the 7443NA for 2016-2017 and 2019, and the 7444NA for 2018, 2020, and 2023, indicating that the two designations are not treated as interchangeable across all years in this application.