Mazda MX-3 Dome Light Bulb Size

The Mazda MX-3 dome light requires bulb size 168 or 912 depending on the specific version of the vehicle. Data for the lighting components covers the range from 1992 to 1995.

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
1994-1995	168
1992-1993	912

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Miniature wedge bulb (T10). 12V, 4.9W.	168
ANSI standard (US & Canada). Wedge bulb (T15). Variant of 921. 12V, 12W.	912

Other Locations

Additional Notes

The Mazda MX-3 dome light uses two distinct bulb types across its production years, with the 168 fitted in 1994-1995 and the 912 fitted in 1992-1993.
Both the 168 and 912 are ANSI-standardized bulbs for the US and Canadian markets, meaning they conform to defined electrical and physical specifications shared across multiple vehicle manufacturers.
The 168 is a T10 miniature wedge bulb rated at 12V and 4.9W, making it a low-wattage lamp suited to interior applications where heat and power draw are minimal concerns.
The 912 is a T15 wedge bulb rated at 12V and 12W, drawing significantly more power than the 168 and producing a correspondingly higher light output for a dome application.
The T10 and T15 designations refer to the tubular envelope width of the bulb, with T10 measuring 10/8 of an inch and T15 measuring 15/8 of an inch, meaning the two bulbs are physically different sizes and are not interchangeable by socket fit alone.
The 912 is noted as a variant of the 921 bulb. While the 921 is rated at 12V and 16.8W, the 912 operates at a lower wattage of 12W, so substituting one for the other may affect brightness and could exceed socket ratings if the higher-wattage variant is used.
The wattage difference between the 168 at 4.9W and the 912 at 12W means the two bulb types are not electrically equivalent, and the socket and wiring in each respective model year are matched to their specified bulb.