The INFINITI FX45 front turn signal uses a 7440NA bulb size while the rear turn signal requires a 12961 bulb size. The replacement chart covers 2003 to 2008 model years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The INFINITI FX45 uses two distinct bulb types across its turn signal positions: the 7440NA for the front and the 12961 for the rear, across the full 2003-2008 model range.
The 7440NA is an ANSI-standardized single-filament wedge bulb in the T20 form factor, rated at 12 volts and 21 watts, with natural amber glass that produces a yellow-orange output without the need for an amber-tinted housing.
The natural amber designation in the 7440NA distinguishes it from the clear-glass 7440, which produces white light. Substituting a clear 7440 in a position designed for the 7440NA may not meet amber output requirements for turn signal regulations in the US and Canada.
The 7440NA carries ANSI standardization, meaning its physical and electrical characteristics conform to a defined North American specification, which allows for cross-brand interchangeability within that standard.
The 12961 is a Philips part number for a miniature wedge bulb in the T10 form factor, using a W2.1x9.5d base, rated at 12 volts and 5 watts.
The W2.1x9.5d base on the 12961 is a specific wedge base type, and bulbs with visually similar T10 bodies but different base configurations are not interchangeable with it.
The 21-watt rating of the 7440NA is significantly higher than the 5-watt rating of the 12961, reflecting their different roles: the front turn signal draws considerably more power than the rear.
The 2003 rear turn signal fitment carries a production date qualifier of "From 11/2002," indicating the 12961 specification applies only to FX45 units produced from November 2002 onward within that model year.