The Mazda RX-8 brake light utilizes a 7443 bulb size for illumination during vehicle operation. Data for the specific component covers the period from 2004 through 2008.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Mazda RX-8 brake lights for model years 2004-2008 use the 7443 bulb, while the center high mount stop light across model years 2004-2011 uses the 7440 bulb.
Both the 7443 and 7440 are T20 wedge-base bulbs operating on a 12-volt system, which is standard for automotive electrical systems.
The 7443 is a dual-filament bulb rated at 21W and 5W, meaning it serves two functions within a single housing, typically combining a brighter stop light output with a dimmer running light output.
The 7440 is a single-filament bulb rated at 21W, designed for applications requiring only one lighting function, which is consistent with its use in the center high mount stop light.
Although the 7443 and 7440 share the same T20 wedge base and physical form factor, they are not interchangeable. Installing a 7440 in place of a 7443 would result in the loss of one filament's function, as the socket is wired to use both filaments of the 7443.
Both bulb types conform to ANSI standards applicable in the United States and Canada, indicating standardized electrical and photometric performance requirements.
The center high mount stop light position on the Mazda RX-8 uses a single-filament bulb across all listed years, which reflects the dedicated, single-function nature of that lighting position.
The 21W output is shared between both bulb types for their primary filament, placing them in the same brightness category for stop light illumination.