Freightliner 108SD Tail Light Bulb Size

The Freightliner 108SD tail light utilizes a 1157 bulb size for the specified lighting component. Available data for the bulb specifications covers the period from 2012 through 2017.

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

Bulb Size by Year Range

Years	Bulb Size
2012-2017	1157

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. 12V, 21W/5W.	1157

Other Locations

Additional Notes

The 1157 is the tail light bulb size for the Freightliner 108SD across all six model years covered in these specifications, spanning 2012-2017.
The 1157 is a dual-filament bulb, meaning it contains two separate filaments within a single glass envelope. One filament operates at 21 watts for braking and turn signal functions, while the other operates at 5 watts for running light functions.
The 1157 uses a BAY15d bayonet base, which is an offset dual-contact base. The two contact pins are positioned at different heights, a design that prevents the bulb from being inserted in the wrong orientation.
The 1157 operates on a 12-volt electrical system, which is consistent with standard automotive and commercial vehicle electrical architecture.
The 1157 is classified under the ANSI standard and is recognized in both the United States and Canada, reflecting its use across North American vehicle applications.
Because the 1157 is a dual-filament type, single-filament substitutes such as the 1156 are not interchangeable with it, despite sharing a similar bayonet base style. The 1156 uses a BAU15s base with symmetrically placed pins and carries only one filament.