International LoneStar Turn Signal Bulb Size

The International LoneStar front turn signal bulb size is 3157NA, a specific replacement bulb designation for this commercial truck model. The replacement chart covers vehicle production spanning 2009 to 2017, detailing bulb size specifications across those years.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Front Turn Signal

Years	Bulb Size
2009-2017	3157NA

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Dual-filament wedge bulb (T25), natural amber glass. 12V, 27W/7W.	3157NA

Other Locations

Additional Notes

The International LoneStar uses the 3157NA bulb for the front turn signal across all listed model years, spanning 2009-2017.
The 3157NA is an ANSI-standardized bulb type, meaning its specifications conform to a defined North American standard recognized in both the United States and Canada.
The 3157NA is a dual-filament bulb, operating at 27W on the high-filament circuit and 7W on the low-filament circuit, which allows it to serve two distinct lighting functions within a single housing.
The bulb operates on a 12V electrical system, consistent with standard automotive voltage.
The "NA" suffix in 3157NA denotes natural amber glass, meaning the amber color is produced by the glass envelope itself rather than by an external coating or lens tint.
The 3157NA carries a T25 wedge base designation, referring to its physical base type, which determines socket compatibility.
Because the 3157 family includes several variants, such as the clear 3157 and the long-life 3157LL, substituting a non-NA variant in the International LoneStar front turn signal position would alter the amber output characteristics intended for that application.