The Lexus GS400 tail light requires a bulb size of 7443 for the rear lighting assembly. Data for the specified component covers the range from 1998 to 2000.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 7443 bulb is the sole bulb type specified across all tail light positions on the Lexus GS400, covering model years 1998-2000.
The 7443 is a dual-filament wedge bulb built to the T20 form factor, operating at 12 volts with a wattage rating of 21W on the high filament and 5W on the low filament.
The dual-filament design of the 7443 allows a single bulb to serve two lighting functions simultaneously, typically stop and tail operation, within one housing.
The 7443 carries ANSI standardization, meaning it conforms to a recognized electrical and physical specification used across the United States and Canada.
Both the inner and outer tail light positions on the GS400 share the same 7443 bulb size across all three model years listed, indicating a uniform fitment requirement throughout the tail light assembly.
The T20 wedge base of the 7443 is a push-in connector type with no separate metal base pins, relying on the wedge-shaped glass envelope to make contact within the socket.
Because the inner and outer tail light positions use identical bulb sizes, a single replacement bulb type is applicable to all tail light sockets on the GS400 for the 1998-2000 model years.
The 7443 is not interchangeable with the single-filament 7440 bulb despite sharing the same T20 wedge base, as the 7440 lacks the second filament required for dual-function operation.