The UD 1800 uses a 67 bulb size for front side marker applications and a 168 bulb size for rear side marker applications. The replacement chart covers vehicle production spanning 1995 to 1998.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The UD 1800 uses bulb size 67 for the front side marker across the 1995-1998 model years.
The 67 bulb is an ANSI-standard single-filament type rated at 12V and 8W, fitted with a BA15s bayonet base.
The BA15s base is a single-contact bayonet fitting, which means it is not interchangeable with dual-contact bayonet bases such as those found on the 1157 or 2057 bulb families.
The 67 bulb is a lower-wattage variant of the 1156, sharing the same BA15s base but drawing less power at 8W compared to the 1156's 21W rating.
Because the 67 and 1156 share a base type, physical fitment may be possible, but the wattage difference makes them non-equivalent replacements for the front side marker position.
The rear side marker on the UD 1800 uses bulb size 168 across the same 1995-1998 model years.
The 168 is an ANSI-standard miniature wedge bulb of the T10 form factor, rated at 12V and 4.9W.
The T10 wedge base relies on contact through the bulb's lead wires rather than a separate metal base, which distinguishes it from the bayonet-style 67 used at the front.
The front and rear side marker positions on the UD 1800 require different bulb types, as the 67 and 168 use incompatible base designs and carry different wattage ratings.
Both the 67 and 168 bulbs conform to ANSI standards applicable in the United States and Canada.