Lexus RX300 Dome Light Bulb Size

The Lexus RX300 dome light uses a DE3175 bulb size for interior illumination. The replacement chart covers vehicle production spanning 1999 to 2003.

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

Years	Bulb Size
1999-2003	DE3175

Description	Bulb Size
ANSI standard (US & Canada). Festoon bulb, 31mm length, end-cap contacts. 12V.	DE3175

The DE3175 is the sole dome light bulb size listed for the Lexus RX300 across all model years covered by these specifications, spanning 1999-2003.
The DE3175 follows the ANSI standard, which is the recognized bulb classification system used in the United States and Canada.
The DE3175 is a festoon-type bulb, a form factor characterized by a cylindrical body that makes contact with its circuit at both flat ends rather than through a base or socket pin.
The 31mm length designation in the DE3175 specification refers to the distance between the two end-cap contacts, which is the critical fitment factor for festoon bulbs in a spring-loaded dome light housing.
The bulb operates at 12 volts, consistent with the standard electrical system voltage found in conventional passenger vehicles.
Because the DE3175 uses end-cap contacts, substituting a festoon bulb of a different length would result in a poor or failed connection within the RX300 dome light housing, as the spring clips are sized to hold a 31mm body under tension.