Lexus GS430 License Plate Bulb Size

Additional Notes

• The Lexus GS430 license plate position uses two distinct bulb sizes across its production run: the 194 and the 168, both of which are T10 miniature wedge bulbs operating at 12 volts.
• The 194 bulb is rated at 3.78 watts, while the 168 bulb is rated at 4.9 watts. Although both share the same T10 wedge base and voltage rating, the wattage difference means they are not interchangeable without consequence.
• The 2005 Lexus GS430 takes the 194 bulb for the license plate position, separating it from all other model years listed in the specifications.
• The 168 bulb is specified for the 2001-2004 model years, making it the fitment used across the majority of the GS430 production span covered by these specifications.
• Both the 194 and 168 are classified under ANSI standards applicable in the United States and Canada, indicating they conform to a defined set of electrical and physical tolerances for those markets.
• The T10 wedge base is a tool-free, push-in socket type. The bulb is retained by the tension of the socket walls rather than by a bayonet or screw mechanism, which is typical for low-wattage license plate applications.
• Because the 194 and 168 share the same T10 wedge base, a 168 bulb is physically capable of seating in a socket designed for a 194, and vice versa. However, the wattage difference means the socket and circuit for the 2005 model year are calibrated for the lower 3.78-watt draw of the 194.
• Installing a 168 bulb in a 2005 GS430 license plate socket would introduce a higher wattage load than the circuit specifies, which can affect the longevity of the socket and the accuracy of any load-sensing systems.