The Peterbilt 375 uses a 194 bulb size for front side marker applications and an 1816 bulb size for rear side marker applications. Replacement chart data covers 1987 through 1996 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 375 uses two distinct bulb types across its side marker positions: the 194 for the front and the 1816 for the rear, across the full 1987-1996 model range.
Both the 194 and 1816 are ANSI-standardized miniature wedge bulbs rated for 12-volt electrical systems, making them compatible with the standard 12V architecture common to commercial trucks.
The 194 bulb follows the T10 wedge form factor and draws 3.78 watts, placing it among the lower-wattage miniature bulbs in automotive applications.
The 1816 bulb uses a T3.25 wedge form factor, which is physically smaller than the T10, and operates at 4 watts, a marginal increase over the front marker bulb.
Although both bulbs share the same wedge-base design and operate on 12 volts, the T10 and T3.25 form factors are not interchangeable due to differences in base size and housing fit.
The wattage difference between the 194 (3.78W) and the 1816 (4W) is minimal, but the distinct physical formats mean substituting one for the other is not supported by the specifications for the Peterbilt 375.
Both bulb types carry ANSI standardization recognized in both the United States and Canada, indicating consistent part availability across North American markets.