Subaru Standard front turn signal bulbs utilize 1156 or 1157 sizes while rear turn signal bulbs use 1156 size. The replacement chart covers 1979 through 1987 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 1156 and 1157 are both ANSI-standardized bulb types recognized across the United States and Canada, making them widely available as replacement parts.
The 1156 is a single-filament bulb operating at 12V and 21W, fitted with a BA15s bayonet base, which has a single locating pin on its collar.
The 1157 is a dual-filament bulb operating at 12V with two wattage ratings, 21W for the high-intensity filament and 5W for the low-intensity filament, fitted with a BAY15d bayonet base.
The BAY15d base of the 1157 features two offset pins, which physically prevents it from being inserted into a BA15s socket designed for the 1156, making the two types non-interchangeable despite their similar appearance.
The Subaru Standard front turn signal for 1982-1987 uses the 1156 single-filament bulb, while the 1979-1981 model years use the 1157 dual-filament bulb in that same position.
The rear turn signal on the Subaru Standard uses the 1156 bulb across all listed model years, from 1979 through 1987.
The front turn signal position is the only location in these specifications where a bulb type change occurs across model years, shifting from the 1157 to the 1156 between the 1981 and 1982 model years.
Because the 1157 carries a secondary 5W filament, its use in the 1979-1981 front turn signal position suggests that circuit in those years was wired to serve a dual function, such as combining turn signal and parking light duties.