Nissan Altima Stepwell Bulb Size

Additional Notes

• The Nissan Altima stepwell position uses two distinct bulb sizes across its model years: the 194 and the 12961, both of which share the T10 miniature wedge form factor.
• The 194 is an ANSI-standardized bulb used in the United States and Canada, rated at 12V and 3.78W, and fits the Nissan Altima stepwell for model years 2014-2019 and 2022-2023.
• The 12961 is a Philips part number designation for a T10 miniature wedge bulb with a W2.1x9.5d base, rated at 12V and 5W, and fits the Nissan Altima stepwell for model years 2002-2006 and 2009.
• Although both bulbs share the T10 wedge profile, the 12961 draws 5W compared to the 194's 3.78W, meaning the two are not electrically identical despite their physical similarities.
• The W2.1x9.5d base designation on the 12961 specifies a wedge base with a 2.1mm wire width and a 9.5mm insertion depth, which is the standard geometry for T10 wedge bulbs in this application.
• The ANSI designation of the 194 indicates it conforms to a standardized specification maintained across multiple manufacturers, whereas the 12961 designation is specific to Philips and may have equivalent cross-reference numbers from other manufacturers.
• The wattage difference between the two bulb types is a relevant fitment consideration, as substituting a 5W bulb in a circuit designed for a 3.78W bulb, or vice versa, may affect socket load tolerances.