The INFINITI M45 side marker requires a bulb size of 12961 for the lighting components. Data for the specified vehicle covers the range from 2003 to 2008.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Infiniti M45 front side marker uses two distinct bulb sizes across its production years, with the 194 fitted to 2003-2004 models and the 12961 fitted to 2006-2010 models.
Both the 194 and 12961 are T10 miniature wedge bulbs sharing the same physical envelope shape, which can create a false impression of interchangeability.
Despite the shared T10 form factor, the two bulbs differ in wattage. The 194 draws 3.78W while the 12961 draws 5W, meaning they are not electrically identical.
The 12961 is a Philips part number designation rather than an ANSI or SAE industry-standard code, and it specifies a W2.1x9.5d base at 12V.
The 194 carries an ANSI standard designation recognized across the United States and Canada, operating at 12V.
The W2.1x9.5d base specification on the 12961 defines the contact pin arrangement and socket fit, which must match the housing socket for proper installation.
The rear side marker on the Infiniti M45 is only listed for the 2003-2004 model years, both of which use the 194 bulb.
For 2006-2010 M45 models, only the front side marker position carries a bulb specification, using the 12961 in all five of those years.