Peterbilt 357 front side marker bulbs use 194 size while rear side marker bulbs use 1816 size. Replacement chart data spans 1986 to 2008 for vehicle production specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Peterbilt 357 uses the 194 bulb for the front side marker position across all listed model years from 1986-2008, making it the most consistently specified bulb in these fitment records.
The 194 is an ANSI-standard miniature wedge bulb with a T10 envelope, rated at 12V and 3.78W, and is recognized in both the US and Canada.
The T10 designation refers to the bulb's tubular glass envelope, with the number indicating its width in eighths of an inch, placing it in the smaller end of the miniature wedge category.
The rear side marker position on the Peterbilt 357 uses the 1816 bulb for model years 1986-1997.
The 1816 is also an ANSI-standard miniature wedge bulb, though it carries a T3.25 envelope designation, rated at 12V and 4W, and is likewise recognized in both the US and Canada.
Although both the 194 and 1816 are miniature wedge-base bulbs operating at 12V, they differ in envelope size and wattage, and the two types are not interchangeable despite their shared base style.
The front and rear side marker positions on the Peterbilt 357 require different bulb types, with the 194 specified at the front and the 1816 at the rear, meaning the two positions draw from separate bulb specifications.
The 1816 draws marginally more power at 4W compared to the 194 at 3.78W, a difference that reflects the distinct optical and housing requirements of rear versus front side marker applications.