The Peterbilt 384 front turn signal bulb size measures 3157NA or 2057, while the rear turn signal bulb size measures 1157 or 2057. The replacement chart covers 2008 to 2016 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 Peterbilt 384 front turn signal takes the 3157NA bulb for model years 2011-2016, while the 2008-2009 model years use the 2057 bulb instead.
The 3157NA is a dual-filament T25 wedge bulb rated at 12V with a 27W high filament and 7W low filament, constructed with natural amber glass that produces a yellow-orange color output without requiring a tinted lens.
The rear turn signal on the Peterbilt 384 uses the 1157 for 2011-2016 and the 2057 for 2008-2009, meaning the front and rear positions share the same bulb only during the 2008-2009 model years.
The 2057 and 1157 both use the BAY15d bayonet base, which features two offset pins that prevent incorrect insertion, and both operate at 12V with dual filaments.
Although the 2057 and 1157 share the same BAY15d base type, their wattage ratings differ. The 2057 runs at 26.9W/8W while the 1157 runs at 21W/5W, making the 2057 the higher-output variant of the two.
The physical base compatibility between the 2057 and 1157 does not establish interchangeability, as the wattage difference between the two bulbs is a relevant fitment consideration for each specified position and model year.
The 3157NA uses a wedge-style base rather than a bayonet base, which means it is physically incompatible with sockets designed for the BAY15d bayonet mount used by the 1157 and 2057.
All three bulb types listed across these specifications conform to ANSI standards applicable in both the United States and Canada.