The Lexus SC400 tail light requires 168 and 1157 bulb sizes depending on the specific production period for the vehicle. Available data covers the range from 1992 through 2000.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Lexus SC400 outer tail light draws from three distinct bulb types across its production run: the 12961, 168, and 1157.
The 1157 is a dual-filament bulb rated at 12V with a 21W/5W output, using a BAY15d bayonet base. Its two filaments serve separate functions within a single housing, typically handling both stop and tail light duties simultaneously.
The 1992-1993 SC400 outer tail light uses the 1157 bulb with its BAY15d bayonet base, which is physically and electrically distinct from the wedge-type bulbs used in later model years.
Starting with the 1994 model year, the SC400 outer tail light transitioned to the 168, a single-filament miniature wedge bulb in the T10 form factor rated at 12V and 4.9W.
The 168 is an ANSI-standardized bulb recognized across the US and Canadian markets, and it continued as the outer tail light specification through the 2000 model year, with the exception of an additional bulb position introduced in 1995.
From 1995 through 2000, the SC400 outer tail light also requires the 12961, a Philips-designated miniature wedge bulb sharing the T10 form factor but carrying a W2.1x9.5d base designation and rated at 12V, 5W.
Although the 168 and 12961 share the T10 wedge form factor, their base designations differ. The 168 follows ANSI standards while the 12961 is a Philips part number with a W2.1x9.5d base, and substituting one for the other without confirming base compatibility may result in an improper fit.
The wattage difference between the 168 (4.9W) and the 12961 (5W) is negligible in practical terms, but the two bulbs occupy separate positions within the outer tail light assembly on 1995-2000 SC400 models rather than serving as interchangeable alternatives.
The shift from the 1157 bayonet-base bulb to the 168 wedge-base bulb between the 1993 and 1994 model years reflects a socket-level change in the outer tail light assembly, meaning the two bulb types are not interchangeable without a corresponding socket modification.