The Peterbilt 385 uses a 194 bulb size for front side marker applications and an 1816 bulb size for rear side marker applications. The replacement chart covers vehicle production spanning 1995 to 2008 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 385 front side marker position uses the 194 bulb across all listed model years from 1995-2008.
The 194 is an ANSI-standard miniature wedge bulb in the T10 form factor, rated at 12 volts and 3.78 watts.
The T10 designation refers to the bulb's tubular envelope size, expressed in eighths of an inch, making it a relatively small wedge-base lamp common in low-intensity marker applications.
The Peterbilt 385 rear side marker position uses the 1816 bulb for model years 1995-1997.
The 1816 is an ANSI-standard miniature wedge bulb in the T3.25 form factor, rated at 12 volts and 4 watts.
The T3.25 form factor of the 1816 is physically distinct from the T10 form factor of the 194, meaning the two bulbs are not interchangeable despite both being wedge-base types operating at 12 volts.
Both the 194 and 1816 carry ANSI standardization recognized in the United States and Canada, indicating conformance to a defined set of electrical and physical tolerances.
The wattage difference between the 194 (3.78W) and the 1816 (4W) reflects a slight variation in light output and current draw, relevant when assessing socket and circuit compatibility.