The Lexus GX460 back up light utilizes a 921 bulb size for illumination purposes during reverse maneuvers. Available information covers a span of time starting from 2010 through 2023.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 921 bulb is the dominant fitment across the Lexus GX460 backup light specifications, appearing in both the standard and outer backup light positions across the majority of model years covered.
The 921 is an ANSI-standard wedge bulb in the T15 form factor, rated at 12 volts and 16 watts, and is a single-filament design used exclusively for backup light duty.
The 3057 is an ANSI-standard dual-filament wedge bulb in the T25 form factor, rated at 12 volts with filaments drawing 27 watts and 7 watts respectively, making it physically and electrically distinct from the 921.
The Lexus GX460 outer backup light for the 2016 model year uses the 3057 bulb rather than the 921, which represents a fitment difference from surrounding model years in that position.
Because the 3057 is a dual-filament bulb and the 921 is a single-filament bulb, the two types are not interchangeable despite both being wedge-base designs.
The T25 base of the 3057 is larger than the T15 base of the 921, which further prevents cross-substitution between the two bulb types in a given socket.
The 2010 outer backup light specification carries a production date qualifier, noting the 921 fitment applies to vehicles built from November 2009 onward.
Both the 921 and 3057 are rated under ANSI standards applicable to the US and Canadian markets, indicating standardized performance and base specifications across those regions.