International S1823 front side marker bulbs use 168 or 1895 bulb sizes, while rear side marker bulbs use 168 size. The replacement chart covers 1980 to 1982 vehicle 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 International S1823 uses two distinct bulb types across its front and rear side marker positions: the 168 and the 1895, both of which are ANSI-standardized miniature wedge bulbs recognized in the US and Canada.
The 168 bulb follows the T10 wedge form factor and operates at 12V with a rated wattage of 4.9W, placing it in the lower-power range typical of side marker and courtesy lighting applications.
The 1895 bulb follows the T5 wedge form factor and operates at 12V with a rated wattage of 0.9W, making it significantly lower in power output than the 168.
The T10 and T5 designations refer to the width of the bulb envelope in units of one-eighth of an inch, meaning the T10 is 10/8 inch wide and the T5 is 5/8 inch wide. These two sizes are not physically interchangeable.
On the International S1823, the rear side marker position uses the 168 bulb across all three model years covered: 1980-1982.
The front side marker position of the S1823 uses the 1895 bulb for the 1980-1981 model years, while the 1982 model year uses the 168 bulb instead.
The front side marker bulb change between the 1981 and 1982 S1823 represents a shift from the T5 form factor to the T10 form factor, which also brings a substantial increase in wattage from 0.9W to 4.9W.
For the 1982 S1823, both the front and rear side marker positions share the same 168 bulb specification, whereas earlier model years use different bulb types front to rear.