BMW 740Li Back Up Light Bulb Size

The BMW 740Li back up light requires a bulb size of 921 for proper installation and function within the rear lighting assembly. Available data for the specified component covers the range from 2011 to 2015.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Bulb Size by Year Range

Years	Bulb Size
2011-2015	921

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Wedge bulb (T15). 12V, 16W.	921

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Additional Notes

The BMW 740Li uses the 921 bulb size for the back up light across the 2011-2015 model years.
The 921 is an ANSI-standardized bulb, meaning its specifications are governed by a recognized North American industry standard applicable in both the United States and Canada.
The 921 bulb follows the T15 wedge form factor, which refers to a wedge-shaped base that connects directly into a socket without a separate metal base or pins.
The 921 operates at 12 volts and 16 watts, which are typical values for incandescent automotive reverse lighting applications.
The wedge base design of the T15 means the bulb is held in place by the tension of the socket itself rather than by a bayonet or screw mechanism.
The 921 shares its T15 wedge base with several other bulb types in the same family, so fitment of a physically similar bulb does not guarantee electrical compatibility unless the wattage and voltage ratings also match.