Ford E-350 License Plate Bulb Size

Additional Notes

• The Ford E-350 license plate bulb is the 194 across the 1975-1993 and 1995-1998 model years, making it the dominant fitment across this vehicle's specification range.
• The 194 is an ANSI-standardized miniature wedge bulb of the T10 form factor, rated at 12 volts and 3.78 watts.
• The 168 is also an ANSI-standardized T10 miniature wedge bulb rated at 12 volts, though it draws 4.9 watts, making it a higher-wattage unit than the 194 despite sharing the same physical form factor.
• Because the 194 and 168 share the T10 wedge base, they are physically interchangeable in the socket, but their wattage ratings differ and each year's specification calls for a distinct type.
• The 1994 Ford E-350 is the sole model year in these specifications to use the 168 bulb for the license plate position, setting it apart from all surrounding years.
• Both bulb types carry ANSI standardization recognized in the United States and Canada, meaning they conform to a defined set of electrical and physical tolerances rather than being proprietary fitments.
• The T10 designation refers to the bulb's tubular envelope width, expressed in eighths of an inch, placing the envelope at 10/8 of an inch, or approximately 1.25 inches wide.
• The wattage difference between the 194 and the 168 reflects a difference in filament resistance, with the 168's filament producing slightly more light output at the cost of greater current draw on the vehicle's electrical circuit.