Lexus GS430 front and rear side marker bulbs use 168, 194, and 7443 sizes, with front markers requiring the smaller bulb size and rear markers requiring the larger 7443 bulb size. The replacement chart covers 2001 through 2007 model 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 GS430 front side marker uses two distinct bulb sizes across its model years: the 194 for 2001-2004 and the 168 for 2005-2007.
Both the 168 and 194 are ANSI-standard miniature wedge bulbs sharing the T10 form factor and a 12V operating voltage, which means they are physically similar in shape and base type.
Despite their shared T10 form factor, the 168 and 194 are not interchangeable on the Lexus GS430 front side marker, as the 168 draws 4.9W while the 194 draws 3.78W, reflecting a difference in filament resistance.
The rear side marker on the Lexus GS430 is specified only for 2001-2004, using the 7443 bulb throughout that entire range.
The 7443 is a dual-filament wedge bulb in the T20 form factor, operating at 12V with a wattage rating of 21W on the primary filament and 5W on the secondary filament.
The T20 form factor of the 7443 is physically larger than the T10 form factor used by the 168 and 194, making the rear side marker socket incompatible with the front side marker bulbs.
The dual-filament design of the 7443 allows a single bulb to serve two lighting functions simultaneously, which is a common arrangement in rear marker and stop/tail applications.
All three bulb types listed for the GS430 conform to ANSI standards applicable in both the United States and Canada, indicating a standardized electrical and physical specification across North American markets.