The Lexus GS400 back up light requires a bulb size of 7440 for the specific lighting components located at the rear of the vehicle. Data for the specified bulb requirements 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 7440 is the sole bulb size listed across all back up light positions for the Lexus GS400, covering model years 1998-2000.
The 7440 bulb follows the ANSI standard applicable in the United States and Canada, classifying it as a regionally standardized automotive lamp.
It is a single-filament wedge bulb, meaning it carries one filament and uses a wedge-style base rather than a bayonet or screw fitting for retention in the socket.
The T20 designation refers to the bulb's body shape, a designation used in the wedge bulb family commonly associated with rear lighting functions such as reverse and turn signals.
The bulb operates at 12 volts and 21 watts, consistent with standard automotive electrical systems and typical of reverse light applications requiring moderate output.
The Outer Back Up Light position for the 2000 model year carries a production date qualifier, specifying fitment up to July 2000, which indicates a mid-year specification that applies only to vehicles produced within that window.