Plymouth Road Runner front and rear side marker bulbs utilized 168, 194, or 1895 bulb sizes depending on production specifications. The replacement chart covers 1968 through 1975 model years with corresponding bulb size data.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Plymouth Road Runner uses three distinct bulb sizes across its side marker positions: 168, 194, and 1895, all of which conform to ANSI standards recognized in both the United States and Canada.
All three bulb types are miniature wedge-base designs, meaning they use a plastic wedge base rather than a metal bayonet or screw base, and are inserted directly into a socket without a separate holder.
The 168 and 194 bulbs share the T10 wedge form factor, making their physical housing the same size, though they differ in wattage output.
The 1895 bulb uses a T5 wedge form factor, which is physically smaller than the T10 housing used by the 168 and 194 bulbs, making it incompatible as a direct substitute for either of those types.
The 168 bulb operates at 12V and 4.9W, while the 194 operates at 12V and 3.78W. Despite sharing the same T10 form factor, the wattage difference means the two are not interchangeable without affecting light output.
The 1895 bulb operates at a notably lower 0.9W, reflecting its role in a smaller, lower-intensity application relative to the T10 bulbs used in later model years.
For the Plymouth Road Runner, the 1968 model year uses the 1895 bulb in both the front and rear side marker positions, representing the only year in the specification to use the T5 form factor.
The 194 bulb is specified for both front and rear side marker positions across the 1969-1972 model years, making it the most widely applied bulb type across the Road Runner's side marker history in these specifications.
The 168 bulb is specified for both front and rear side marker positions across the 1973-1975 model years, indicating a shift from the 194 to a higher-wattage T10 bulb in the later production run.
Front and rear side marker positions share identical bulb specifications for every model year listed, meaning no distinction exists between the two positions within any given year.