The Buick LaCrosse side marker requires a 194 bulb size for proper installation and function within the lighting assembly. Data for the specified component covers the range from 2005 to 2009.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Buick LaCrosse front side marker position uses three distinct bulb types across its model years: the 194, 3757NA, and 7443, each belonging to a different wedge bulb family and wattage class.
The 194 is a T10 miniature wedge bulb rated at 12V and 3.78W, making it the lowest-wattage bulb among the three types specified for the LaCrosse side marker positions.
The 7443 is a T20 dual-filament wedge bulb rated at 12V with a 21W main filament and a 5W secondary filament. Its dual-filament design distinguishes it from the single-purpose low-wattage 194 bulb it replaced in earlier model years.
The 3757NA is a T25 dual-filament wedge bulb with natural amber glass, rated at 12V. The amber glass is integral to the bulb itself, meaning the color is produced by the glass envelope rather than by the lens housing.
The 7443 is specified only for 2014-2016 Buick LaCrosse front side marker applications equipped with halogen capsule headlamps, indicating a trim-level or package dependency for that bulb fitment.
The 3757NA and 7443 are both dual-filament wedge bulbs, but they occupy different physical sizes, T25 and T20 respectively, and are not interchangeable with each other or with the single-filament T10 194 bulb.
All three bulb types conform to ANSI standards applicable in the United States and Canada, classifying them as standardized replacements within the North American market.
The rear side marker position on the Buick LaCrosse uses the 194 bulb exclusively across all years listed, covering model years 2005-2009.
The front and rear side marker positions share the same 194 bulb specification for model years 2005-2009, meaning both positions drew from the same bulb type during that period.
No rear side marker bulb data is listed for model years 2010-2016, while the front side marker position carries specifications through 2016.