Lexus IS500 Trunk Bulb Size

The Lexus IS500 trunk utilizes 194 and 12961 bulb sizes for the internal lighting components. Data for the specified vehicle covers the range from 2022 through 2024.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Bulb Size by Year Range

If US Type and EU Type show the same value, a direct cross-reference for this bulb is not available or the data is insufficient.

Years	US Type	EU Type	Shop
2023-2024	194	W5W	Check Price
2022	12961	12961	Check Price

Bulb Specifications

Description	Type	Shop
ANSI standard (US & Canada). Miniature wedge bulb (T10). 12V, 3.78W.	194	Check Price
ECE standard (Europe & worldwide). Single-filament signalling bulb with W2.1x9.5d wedge base. 12V, 5W.	W5W	Check Price
Philips part number. Miniature wedge bulb (T10) with W2.1x9.5d base. 12V, 5W.	12961	Check Price

Other Locations

Additional Notes

The 194 is an ANSI-standardized miniature wedge bulb in the T10 form factor, rated at 12 volts and 3.78 watts. It is the recognized standard designation used across the United States and Canada.
The 12961 is a Philips part number rather than an industry-wide standard designation. It shares the T10 form factor with the 194 but uses a W2.1x9.5d base and is rated at 12 volts and 5 watts, giving it a higher wattage output than the 194.
Although both bulbs share the T10 form factor, the 194 and 12961 are not the same specification. The difference in wattage (3.78W versus 5W) and base designation means the two are distinct parts assigned to different model years.
The Lexus IS500 uses the 194 for the 2023-2024 trunk application and the 12961 for the 2022 trunk application. These two bulb types are not interchangeable across those years according to the fitment data.