The Lexus RX300 front and rear side marker bulbs use 194 or 168 size bulbs for replacement applications. The replacement chart covers 1999 to 2003 production years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Lexus RX300 uses two bulb types across its side marker positions: the 194 and the 168, both of which follow ANSI standards recognized in the US and Canada.
Both the 194 and 168 are miniature wedge bulbs sharing the T10 form factor and a 12-volt operating voltage, which places them in the same physical bulb family.
Although the 194 and 168 share the T10 form factor, they differ in wattage. The 194 draws 3.78W, while the 168 draws 4.9W, making them electrically distinct despite their physical similarity.
The front and rear side marker positions on the RX300 use identical bulb sizes for each model year, meaning no distinction exists between front and rear fitment within a given year.
The 194 bulb applies to the 2001-2003 RX300 for both front and rear side marker positions.
The 168 bulb applies to the 1999-2000 RX300 for both front and rear side marker positions.
A bulb change occurred between the 2000 and 2001 model years, where the side marker specification shifted from the 168 to the 194 across all marker positions.
Because the 194 and 168 share the T10 wedge base, physical installation of either bulb into the other's socket is possible, though the wattage difference means they are not rated as interchangeable replacements.