Peterbilt 377 License Plate Bulb Size

The Peterbilt 377 license plate light utilizes bulb sizes 67 and 97 for the exterior lighting system. Available information covers the production span from 1987 through 2001 for the specified vehicle components.

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
1998-2001	67
1987-1997	67
1987-1997	97 (With Halogen Capsule Headlamps)

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Lower wattage variant of 1156. 12V, 8W.	67
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Variant of 1156. 12V, 13W.	97

Other Locations

Additional Notes

The bulb size 67 is the most consistently specified license plate bulb across the Peterbilt 377, appearing as the sole fitment for model years 1997-2001 and as one of two options for model years 1987-1996.
Both the 67 and 97 are ANSI-standardized single-filament bulbs sharing the BA15s bayonet base, which means they are physically interchangeable in terms of socket fit despite differing in wattage output.
The 67 operates at 12V and 8W, while the 97 operates at 12V and 13W, making the 97 a higher-wattage variant within the same base family.
Both bulbs are classified as lower-wattage variants of the 1156, a widely used automotive single-filament bulb with the same BA15s base, though the 1156 itself is rated at a higher wattage than either the 67 or 97.
For the Peterbilt 377 model years 1987-1996, the presence of halogen capsule headlamps determines which license plate bulb size applies, with the 97 specified exclusively for vehicles equipped with that headlamp configuration.
The standard fitment of the 67 applies to 1987-1996 model years without halogen capsule headlamps, indicating that the headlamp system type is a critical factor in selecting the correct license plate bulb for those years.
From 1997 onward through 2001, only the 67 is listed regardless of headlamp configuration, reflecting a single-bulb specification for those years.
The wattage difference between the 67 and 97 is relevant to electrical load considerations, as substituting the 97 in a circuit designed for the 67 introduces a higher draw of approximately 5W per socket.