The Lexus SC400 front side marker uses a 194 bulb size while the rear side marker requires a 168 bulb size. The replacement chart covers 1992 to 2000 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 SC400 uses the 194 bulb for the front side marker position across all model years from 1992 to 2000.
The rear side marker position on the SC400 uses the 168 bulb across the same 1992-2000 model year span.
Both the 194 and 168 are ANSI-standardized bulbs recognized in the United States and Canada, meaning they conform to a defined set of electrical and physical specifications.
Both bulbs share the T10 miniature wedge form factor, a small single-contact base that is retained by friction rather than a locking mechanism.
Both bulbs operate on a 12-volt system, consistent with standard automotive electrical architecture.
Although the 194 and 168 share the same T10 wedge base, they are not interchangeable between positions on the SC400 because they differ in wattage: the 194 is rated at 3.78W while the 168 is rated at 4.9W.
The wattage difference between the two bulbs means each draws a distinct level of current, which is relevant to socket and circuit load ratings specific to each position.