Mazda 5 Back Up Light Bulb Size

The Mazda 5 back up light bulb size chart specifies 7440 and 921 bulb sizes for this vehicle model. The replacement chart covers 2006 through 2015 production years with corresponding bulb size data.

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
2012-2015	7440
2006-2010	921

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament wedge bulb (T20). 12V, 21W.	7440
ANSI standard (US & Canada). Wedge bulb (T15). 12V, 16W.	921

Other Locations

Additional Notes

The Mazda 5 backup light specifications cover model years 2006-2015 and reference two distinct bulb types: the 7440 and the 921.
The 7440 is an ANSI-standard single-filament wedge bulb in the T20 form factor, rated at 12V and 21W.
The 921 is an ANSI-standard wedge bulb in the T15 form factor, rated at 12V and 16W.
The T20 form factor of the 7440 is physically larger than the T15 form factor of the 921, which means the two bulb types are not interchangeable despite sharing the same 12V operating voltage.
The 7440 draws 21W compared to the 921's 16W, reflecting a higher current draw that corresponds to the socket and wiring expectations of vehicles specifying that bulb.
The Mazda 5 (2012-2015) specifies the 7440 bulb for the backup light position.
Model years 2006-2010 specify the 921 bulb, indicating a change in socket type occurred between the 2010 and 2012 model years.
Both the 7440 and 921 conform to ANSI standards applicable in the United States and Canada, meaning bulbs sourced from either market are electrically and physically equivalent within each respective type.
The single-filament design of the 7440 means it serves one lighting function only, which is consistent with its application in a dedicated backup light socket.