Lincoln MKZ front side marker bulbs use 168NA size while rear side marker bulbs use 194 size. The replacement chart covers 2007 to 2012 vehicle production years with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Lincoln MKZ front side marker positions use the 168NA bulb across the 2007-2012 model years.
The 168NA is an ANSI-standard miniature wedge bulb in the T10 form factor, rated at 12V and 4.9W, and features natural amber glass rather than a clear envelope.
The natural amber glass of the 168NA produces its amber color through the glass itself, which distinguishes it from clear T10 bulbs that rely on a colored lens housing to achieve the same effect.
The Lincoln MKZ (2007-2009) rear side marker positions use the 194 bulb.
The 194 is also an ANSI-standard T10 miniature wedge bulb rated at 12V, but draws 3.78W, making it lower in wattage than the 168NA used at the front.
Both the 168NA and 194 share the T10 wedge form factor, yet they are not interchangeable in all positions on this vehicle. The front position specifies the 168NA with its built-in amber glass, while the rear position specifies the clear-envelope 194.
Substituting a clear T10 bulb such as the 194 into a front side marker position designed for the 168NA could affect the amber color output if the housing lens does not itself provide amber filtration.
Both bulb types conform to ANSI standards applicable in the United States and Canada, indicating they meet the same regulatory framework for automotive lighting in those markets.