The Mazda MX-3 brake light requires a 1157 bulb size for proper installation and function within the lighting assembly. Data for the specific component covers the range from 1992 through 1995.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Mazda MX-3 uses the 1157 bulb for brake lights across all four model years in the specification, spanning 1992-1995.
The 1157 is a dual-filament bulb, meaning it serves two separate lighting functions within a single housing. Its higher-wattage filament at 21W handles the brake light function, while the lower-wattage filament at 5W handles the tail light function.
The 1157 operates on a 12V system and uses a BAY15d bayonet base, a two-pin offset base design that prevents incorrect installation by ensuring the bulb can only be seated in one orientation.
The center high mount stop light on the MX-3 uses the 921 bulb for all model years from 1992-1995, a different bulb type from the one used in the standard brake light positions.
The 921 is a single-filament wedge bulb in the T15 form factor, rated at 12V and 16W. Unlike the 1157, it has no bayonet base and is held in place by the tension of its socket contacts alone.
Because the 1157 and 921 use entirely different base types, a bayonet versus a wedge, the two bulbs are not interchangeable with each other despite both operating on a 12V system.
Both the 1157 and 921 are ANSI-standardized bulbs, meaning their electrical and physical specifications conform to a defined industry standard applicable across the United States and Canada.
The dual-filament design of the 1157 is a relevant fitment consideration. Replacing it with a single-filament bulb of a similar base type would result in the loss of either the tail light or brake light function in that position.