Lexus LX570 front dome light uses 12961 bulb size while rear dome light requires DE3175 bulb size. Replacement chart covers 2008 to 2016 production years with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Lexus LX570 uses two distinct bulb types across its dome light positions: the 12961 in the front and the DE3175 in the rear, with both positions remaining consistent across the 2008-2016 model years (excluding 2012).
The 12961 is a Philips part number designating a miniature wedge-style bulb in the T10 form factor, which uses a W2.1x9.5d base and operates at 12V with a 5W output.
The T10 wedge base on the 12961 relies on friction-fit contacts rather than end caps or pins, meaning it is not interchangeable with festoon-style bulbs despite both being low-voltage interior lamps.
The DE3175 is an ANSI-standardized designation recognized in the United States and Canada, referring to a festoon bulb with a 31mm length that makes contact through metal end caps at each end of the housing.
Festoon bulbs such as the DE3175 are held in place by spring-loaded clips within the fixture, a mounting method that is physically incompatible with wedge-base sockets used by the 12961.
The 12961 operates at 12V and 5W, while the DE3175 specification provided lists only a 12V rating without a wattage value, indicating the two bulbs carry different electrical profiles.
Because the front dome position on the Lexus LX570 requires a wedge-base T10 bulb and the rear dome position requires a 31mm festoon, substituting one type for the other is not physically possible without modifying the socket.
The DE3175 designation is specific to the 31mm festoon length, and festoon bulbs of differing lengths such as 28mm or 36mm are not direct replacements, as the end-cap contact fit depends on the fixture span.