Ford Focus front side marker bulb size 168, rear side marker bulb size 3157, and side marker bulb size 194 represent the distinct bulb specifications for this vehicle model. The replacement chart covers 2008 to 2018 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 Ford Focus uses the 168 bulb for the front side marker position across the 2008-2018 model years, making it the most consistently specified bulb in these listings.
The 168 is an ANSI-standard miniature wedge bulb with a T10 envelope, rated at 12V and 4.9W, and is classified for use in the United States and Canada.
The 194 bulb shares the same T10 wedge form factor as the 168 but draws slightly less power at 3.78W versus 4.9W, which means the two types are physically similar yet not electrically identical.
The 194 bulb is designated for the mirror-mounted side marker position on the Ford Focus for the 2008 and 2012-2018 model years.
The 3157 is a dual-filament T25 wedge bulb rated at 12V with a high-filament draw of 27W and a low-filament draw of 7W, reflecting its role in positions that serve more than one lighting function.
The Ford Focus rear side marker uses the 3157 bulb for the 2012-2018 model years.
Because the 168 and 194 share the T10 wedge base, physical installation may be possible in either socket, but their differing wattage ratings means substituting one for the other falls outside the manufacturer-specified fitment.
The 3157 dual-filament construction is not interchangeable with the single-filament 168 or 194 bulbs, as the socket configurations and filament counts differ between the T25 and T10 wedge families.
All three bulb types listed, the 168, 194, and 3157, conform to ANSI standards applicable in the United States and Canada, indicating standardized base and envelope specifications across the range.
The mirror-designated 194 position represents a physically distinct mounting location from the main rear side marker socket, and the two rear positions on applicable model years therefore require different bulb types.