The Subaru GLF front turn signal requires either a 1156 or 1157 bulb size, while the rear turn signal uses a 1156 bulb size. The replacement chart covers vehicle production years from 1980 to 1982 with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Subaru GLF uses two bulb types across its front and rear turn signal positions for the 1980-1982 model years: the 1156 and the 1157.
The 1156 is a single-filament bulb operating at 12V and 21W, fitted with a BA15s bayonet base, and is classified under the ANSI standard applicable to the US and Canada.
The 1157 is a dual-filament bulb operating at 12V with filaments rated at 21W and 5W, fitted with a BAY15d bayonet base, and also carries the same ANSI classification.
The BA15s and BAY15d bayonet bases are physically distinct. The BA15s base has a single locating pin, while the BAY15d base has two offset pins, making the 1156 and 1157 non-interchangeable by base design alone.
The rear turn signal position on the Subaru GLF uses the 1156 bulb across all three model years covered in the specifications.
The front turn signal position on the 1982 Subaru GLF uses the 1156, while the 1980-1981 model years use the 1157, indicating a change in front turn signal bulb type between the 1981 and 1982 model years.
Because the 1157 carries a dual-filament design, its use in the 1980-1981 front turn signal position suggests that position served more than one lighting function during those years.