The INFINITI QX56 front turn signal bulb size measures 7440NA or 7440, while the rear turn signal bulb size measures 7440NA, 2356, or 2456. The replacement chart covers vehicle production years spanning 2004 through 2013 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 7440 and 7440NA are the most frequently specified bulbs across the INFINITI QX56 turn signal positions, appearing in both front and rear applications across multiple model years.
Both the 7440 and 7440NA are single-filament T20 wedge bulbs rated at 12V and 21W under the ANSI standard, making them electrically identical in output.
The key distinction between the 7440 and 7440NA is the glass envelope: the 7440NA uses natural amber-tinted glass to produce its amber signal color, while the 7440 relies on a clear envelope, typically paired with an amber-colored lens housing.
The INFINITI QX56 front turn signal position uses the 7440 for 2004-2010 and transitions to the 7440NA for 2011-2013, reflecting a shift to natural amber glass in later model years.
The rear turn signal position shows considerably more variation across model years, with four distinct bulb types specified between 2004 and 2013.
The 3157 is a dual-filament T25 wedge bulb rated at 12V with a 27W high-filament and 7W low-filament output, and it is specified for the QX56 rear turn signal in 2004-2005.
The 2356 is a dual-filament bulb with a BAY15d bayonet base rated at 12V, and it is specified for the rear turn signal in 2006 and 2010.
The 2456 is a festoon-style bulb for specialty applications rated at 12V, and it is specified for the rear turn signal in 2007-2009.
Because the rear turn signal position spans four different bulb types across the 2004-2013 production range, year-specific verification is particularly important, as these bulb types use physically incompatible bases and housings that prevent cross-year substitution.
All bulb types listed across both turn signal positions conform to the ANSI standard applicable in the United States and Canada.