The Lexus HS250h front turn signal bulb uses 3357NA or 3457NA size, while the rear turn signal bulb uses 7440NA size. The replacement chart covers 2010 to 2012 production years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Lexus HS250h uses three distinct bulb types across its front and rear turn signal positions: the 3357NA, 3457NA, and 7440NA, all of which conform to ANSI standards recognized in the United States and Canada.
The 7440NA is the rear turn signal bulb for the HS250h across all three model years (2010-2012), making it the most consistent fitment in these specifications.
The 7440NA is a single-filament wedge bulb in the T20 form factor, rated at 12V and 21W, with natural amber glass that produces an amber color without the need for a tinted lens or colored coating.
The front turn signal of the HS250h uses the T25 wedge form factor for all three model years, though the specific bulb type varies by year.
The 3357NA and 3457NA share the same T25 wedge form factor and both carry a 12V, 27W rating on their primary filament, along with natural amber glass, which may suggest a degree of physical similarity.
Despite their similarities, the 3357NA is a single-filament bulb while the 3457NA is a dual-filament bulb rated at 27W/7W, meaning the two are not functionally interchangeable even if they share the same housing form factor.
The 2011 HS250h front turn signal position specifies the 3457NA, which differs from the 3357NA used in the 2010 and 2012 model years, making year verification necessary before sourcing a front turn signal bulb for this vehicle.
The dual-filament design of the 3457NA, used in the 2011 front turn signal, allows a single bulb to serve two lighting functions simultaneously, with the lower 7W filament typically serving a secondary role such as a parking or daytime running light.
Installing a 3357NA in a 2011 front turn signal socket designed for the 3457NA would result in the loss of the secondary filament function, as the single-filament 3357NA cannot replicate the dual-filament behavior of the 3457NA.
All six bulb positions across the three model years are rated at 12V, consistent with the standard electrical system voltage found in conventional passenger vehicles.