BMW 750i Back Up Light Bulb Size

The BMW 750i back up light requires a bulb size of 921 for the rear lighting assembly. Available data for the specified component covers the period from 2006 through 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
2006-2015	921

Bulb Specifications

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

Other Locations

Additional Notes

The BMW 750i uses the 921 bulb size for the back up light across the 2006-2015 model years.
The 921 is an ANSI-standardized bulb type, meaning its specifications are governed by a recognized North American standard applicable in both the United States and Canada.
The 921 bulb uses a wedge-style base, designated T15, which refers to a tubular bulb body approximately 15 eighths of an inch wide that is held in its socket by the tension of the base contacts rather than by a bayonet or screw mechanism.
The 921 operates at 12 volts, consistent with the standard electrical system voltage found in passenger vehicles.
The 921 is rated at 16 watts, placing it in the range typical of reverse light applications where moderate output is required.
Because the 921 is a wedge-type bulb, it is not interchangeable with bayonet-base or screw-base bulb types even when wattage or voltage ratings are otherwise similar.
The T15 wedge form factor is shared by several bulb numbers in the ANSI series, so substitution with another T15 bulb would require verification that the voltage and wattage ratings also match the 921 specification.