Mercedes-Benz E350 Back Up Light Bulb Size

The Mercedes-Benz E350 back up light requires a bulb size of 921 for the specific lighting component located at the rear of the vehicle. Available data for the bulb specifications covers the range from 2008 through 2013.

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
2008-2013	921

Bulb Specifications

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

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Additional Notes

The Mercedes-Benz E350 uses the 921 bulb size for the back up light across the 2008-2013 model years.
The 921 is a wedge-type bulb, classified under the T15 designation, which refers to its tubular glass envelope size of 15/8 inches.
Wedge bulbs do not use a separate metal base or pins. Instead, the glass envelope itself is pinched at the bottom to form a wedge shape that locks directly into the socket.
The 921 operates at 12 volts and draws 16 watts, placing it in the low-wattage range typical of reverse lighting applications.
The 921 follows the ANSI standard, meaning it conforms to specifications recognized in both the United States and Canada.
The T15 wedge form factor is shared by several bulb numbers in the same family, and not all T15 wedge bulbs are electrically identical. Substitutions with different wattage ratings may affect socket compatibility or circuit load.