Freightliner Cascadia Side Marker Bulb Size

The Freightliner Cascadia front side marker bulb uses a 4157NA size bulb. The replacement chart covers vehicle production spanning 2008 to 2017.

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

Front Side Marker

Years	Bulb Size
2008-2017	4157NA

Description	Bulb Size
ANSI standard (US & Canada). Dual-filament wedge bulb (T25), natural amber glass. 12V, 27W/7W.	4157NA

The Freightliner Cascadia uses the 4157NA bulb for the front side marker position across all listed model years from 2008-2017, indicating a consistent fitment specification throughout that period.
The 4157NA is an ANSI-standardized bulb, meaning its specifications conform to a recognized North American standard applicable in both the United States and Canada.
The bulb operates on a 12-volt system and carries a dual-wattage rating of 27W and 7W, which corresponds to its dual-filament construction. The higher wattage filament typically serves the turn signal function, while the lower wattage filament serves the marker or parking light function.
The T25 designation refers to the bulb's envelope size, expressed in eighths of an inch, placing it in a mid-range size category common to automotive signal lighting applications.
The natural amber glass construction of the 4157NA produces an amber output directly from the glass rather than relying on a colored lens, which is a relevant fitment detail when replacing bulbs in housings designed for this configuration.
The "NA" suffix in the 4157NA designation specifically denotes the natural amber glass variant, distinguishing it from the clear-glass 4157 bulb. Substituting a clear 4157 in a position specified for the 4157NA may affect the color output of the light assembly.