Lexus IS350 Interior Door Bulb Size

Additional Notes

• The 168 bulb is the sole interior door bulb size listed across all model years of the Lexus IS350 covered in these specifications, spanning 2006-2009 and 2016-2023.
• The 168 is an ANSI-standardized bulb designation recognized in both the United States and Canada, meaning its electrical and physical characteristics conform to a defined industry standard rather than a proprietary specification.
• The bulb operates at 12 volts and 4.9 watts, which places it in the low-wattage range typical of interior courtesy lighting where heat output and power draw are kept minimal.
• The T10 designation refers to the bulb's tubular glass envelope, with the number indicating a width of 10 eighths of an inch. This shape is a common form factor in automotive interior applications.
• The wedge base type means the bulb has no separate metal base or pins; instead, the glass envelope itself is pinched at the bottom to form a wedge that locks directly into a compatible socket, eliminating the need for a bayonet or screw fitting.
• Because the 168 and T10 wedge format are widely standardized, aftermarket and LED replacement bulbs marketed under the T10 or W5W designation are generally physically interchangeable, though electrical compatibility should be confirmed before substitution.
• The consistent use of the 168 across the 2016-2018 and 2021-2023 production periods of the IS350 indicates that the interior door socket specification was carried over without alteration through those generations.