The Lexus IS300 parking light utilizes bulb size 7444NA or 168 depending on the specific version required for the vehicle. Data for the bulb sizes covers the range from 2001 to 2021.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 7444NA is the front parking light bulb used in the Lexus IS300 across the 2016-2019 and 2021 model years.
The 7444NA is a dual-filament wedge bulb built to the T20 form factor, rated at 12 volts with a 21W/5W power draw across its two filaments.
The natural amber glass of the 7444NA produces a colored output directly from the bulb itself, rather than relying on an amber-tinted lens to achieve the required turn signal color.
The 7444NA conforms to ANSI standards applicable in both the United States and Canada.
The 2001 Lexus IS300 uses the 168 bulb for the front parking light, a specification that differs from all other listed model years.
The 168 is a single-filament miniature wedge bulb in the T10 form factor, rated at 12 volts and 4.9 watts.
The T10 and T20 designations refer to the outer width of each bulb type, with T10 being narrower than T20. The two form factors are physically incompatible and not interchangeable.
The wattage difference between the 168 (4.9W) and the 7444NA (21W/5W) reflects a substantial gap in power consumption, which also means the two bulbs are not electrically equivalent.