Porsche 911 Back Up Light Bulb Size

The Porsche 911 back up light utilizes P21W, 1156, and 1141 bulb sizes depending on the specific production version. Available data for the lighting components covers the range from 1965 to 2012.

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
1973-2012	1156
1971-1972	1141
1965-1970	1156

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1156
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1141

Other Locations

Additional Notes

The Porsche 911 back up light bulb specification calls for the 1156 across model years 1965-1975 and 1973-2012, with the 1141 specified for the 1971-1972 model years.
Both the 1156 and 1141 are ANSI-standardized bulb types recognized in the United States and Canada.
Each bulb type operates at 12 volts with a 21-watt output, placing them in the standard incandescent range for automotive reverse lighting applications.
Both the 1156 and 1141 use a BA15s bayonet base, which is a single-contact bayonet mount with a 15mm base width.
The single-filament construction of both bulb types is consistent with a dedicated reverse light function, as opposed to dual-filament bulbs used in combination stop and tail light applications.
Although the 1156 and 1141 share the same BA15s base and identical voltage and wattage ratings, they are distinct part numbers and are not universally treated as interchangeable in all fitment guides.
The BA15s base designation indicates a single center contact at the base, which distinguishes it from the BA15d double-contact variant used in dual-filament applications.