The Lincoln MKZ tail light requires a 3157NA bulb size for proper installation and function. Data for the specified lighting component covers the range from 2007 through 2009.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Lincoln MKZ inner tail light position uses two distinct bulb types across the 2007-2009 model years: the 161 and the 3157NA.
The 161 is a T10 miniature wedge bulb rated at 12V and 1W, conforming to ANSI standards applicable in both the United States and Canada.
The 3157NA is a T25 dual-filament wedge bulb with natural amber glass, rated at 12V with a dual-wattage output of 27W and 7W, also conforming to ANSI standards for the US and Canadian markets.
The dual-filament design of the 3157NA means it serves two separate lighting functions within a single bulb, with the higher 27W filament typically handling stop or turn signal duties and the lower 7W filament handling running light functions.
The natural amber glass of the 3157NA produces a colored output without the use of a tinted lens or external filter, which is a characteristic specific to the NA suffix designation within the 3157 bulb family.
The 161 and 3157NA are not interchangeable with each other, as they differ in base type, wattage, filament count, and physical construction.
Both bulb types follow the wedge-base format, meaning they are retained by the socket through tension rather than a bayonet or screw mechanism.
The T10 designation of the 161 refers to a tubular envelope roughly 10 eighths of an inch wide, while the T25 designation of the 3157NA refers to a larger tubular envelope approximately 25 eighths of an inch wide, making the two physically incompatible in the same socket.