Subaru Brat front turn signal bulbs measure 1156 or 1157 in size, while rear turn signal bulbs measure 1156 in size. The replacement chart covers 1978 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 used in the United States and Canada, operating at 12 volts.
The 1156 is a single-filament bulb rated at 21W, fitted with a BA15s bayonet base.
The 1157 is a dual-filament bulb rated at 21W and 5W, fitted with a BAY15d bayonet base. The two filaments serve separate lighting functions within a single housing.
Although the 1156 and 1157 share a similar bayonet-style base design, their bases are not identical. The BA15s base has a single contact pin, while the BAY15d base has two offset contact pins, making the two bulb types non-interchangeable.
The Subaru Brat uses the 1156 bulb for the rear turn signal across all model years covered in the specifications, from 1978-1987.
The front turn signal of the Subaru Brat uses the 1156 bulb for model years 1982-1987.
For model years 1978-1981, the Subaru Brat front turn signal uses the 1157 bulb rather than the 1156 used in later years.
Because the front turn signal socket changed between the 1981 and 1982 model years, a 1156 bulb cannot be substituted into a socket designed for the 1157, and vice versa, without a socket adapter or wiring modification.