The Subaru GL uses the 194 bulb for both the front and rear side markers across the 1980-1989 model years.
The 194 is a miniature wedge-type bulb, classified under the T10 form factor, which refers to its tubular shape measuring 10 millimeters in width at its widest point.
The 194 bulb operates at 12 volts with a power draw of 3.78 watts, placing it in the low-wattage range typical of side marker and courtesy lighting applications.
The 194 follows ANSI standardization recognized in both the United States and Canada, meaning units sourced from either market conform to the same electrical and physical specifications.
The wedge base design of the 194 means the bulb is held in its socket by the tension of the base itself rather than by a separate bayonet or screw mechanism.
Because the front and rear side marker positions on the Subaru GL share the same bulb size, a single bulb type services both locations on the vehicle.
The T10 wedge format of the 194 is a widely produced bulb type, and aftermarket variants including LED replacements are commonly manufactured to the same base specification, though electrical compatibility with the original socket depends on the specific replacement unit.