The Lexus GS350 front turn signal requires bulb sizes 7444NA, 7443NA, or 7440NA, while the rear turn signal uses 7440 or 7440NA bulb sizes. The replacement chart covers vehicle production years spanning 2007 to 2019 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 three most frequently specified bulb types across the Lexus GS350 turn signal positions are the 7440NA, 7443NA, and 7444NA, all of which conform to ANSI standards recognized in the United States and Canada.
All four bulb types found in these specifications share the T20 wedge base form factor and operate at 12 volts, making them part of the same broad bulb family despite differences in filament count and glass treatment.
The 7440NA and 7440 are both single-filament T20 wedge bulbs rated at 21W, while the 7443NA and 7444NA are dual-filament T20 wedge bulbs rated at 21W and 5W, with the higher wattage filament serving the turn signal function and the lower wattage filament serving a secondary role such as parking or daytime running light.
The 7440NA, 7443NA, and 7444NA all feature natural amber glass, which produces an amber output without the use of an amber-coated or painted lens, distinguishing them from their clear-glass counterparts such as the 7440.
The 7440 specified for the rear turn signal in 2013-2015 uses clear glass rather than natural amber glass, which is the sole optical difference between it and the 7440NA used in the same rear position for 2007-2011.
The front turn signal of the Lexus GS350 alternates between single-filament and dual-filament bulb types across model years, meaning the 7440NA used in 2007-2011 is not a direct drop-in replacement for the 7443NA or 7444NA specified for later years, despite sharing the same T20 base.
For the 2016 and 2018 front turn signal positions, the specification lists the 7443NA under a "With 2 Headlamps" condition, while the 2017 front position lists the 7444NA under the same condition, indicating that the same headlamp configuration does not guarantee the same bulb size across adjacent model years.
The 2019 front turn signal specifies the 7444NA under a "With LED Headlamps" condition, reflecting that headlamp technology on the GS350 is a determining factor in front turn signal bulb selection for that year.
The 7443NA and 7444NA are both dual-filament T20 natural amber bulbs with identical voltage and wattage ratings, yet they carry distinct ANSI part numbers, and substituting one for the other without confirming socket compatibility could result in an improper fit.
No rear turn signal bulb size is listed for the 2012, 2016, 2017, 2018, or 2019 model years in these specifications, and no front turn signal bulb size is listed for the 2012 model year.