The Lexus RX350 back up light utilizes a 921 bulb size for illumination purposes across various production versions of the vehicle. Data for the specific component covers a range from 2007 to 2022.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 921 bulb follows the ANSI standard for the US and Canadian markets. It is a single-filament wedge bulb in the T15 form factor, rated at 12 volts and 16 watts.
The 3057 bulb also conforms to the ANSI standard for the US and Canadian markets. It is a dual-filament wedge bulb in the T25 form factor, rated at 12 volts with filaments drawing 27 watts and 7 watts respectively.
The Lexus RX350 uses the 921 bulb for the standard back up light across the 2007-2018, 2021, and 2022 model years.
The inner back up light position on the RX350 uses two distinct bulb types depending on the model year, making direct substitution between years inadvisable without confirming the correct specification first.
For the inner back up light, the 3057 dual-filament bulb was fitted on the 2010-2015 model years, with the exception of the 2009 model year, which used the single-filament 921 instead.
The 2016 inner back up light specification carries a production date qualifier, with units built from October 2015 onward requiring the 921 bulb rather than the 3057.
The T15 and T25 designations refer to the physical size of the wedge base, with T25 being the larger of the two. These two form factors are not interchangeable despite both using a wedge-style base.
The wattage difference between the 921 (16W) and the 3057 (27W/7W) reflects a meaningful distinction in power draw, which is relevant when replacing one type with the other is being considered for any position where both have been used across different model years.