The Mitsubishi Precis brake light uses the 1157 bulb size along with the 1156 and P21W options for various lighting applications. Data for the specific components covers the period from 1987 through 1994.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Mitsubishi Precis uses two distinct bulb types across its model years for the brake light position: the 1157 for 1987-1991 and the 1156 for 1992-1994.
The 1157 is a dual-filament bulb rated at 12V with a 21W/5W output, mounted on a BAY15d bayonet base. The dual-filament design allows it to serve both a running light function and a brighter brake light function within a single housing.
The 1156 is a single-filament bulb rated at 12V, 21W, using a BA15s bayonet base. Because it carries only one filament, it is dedicated solely to the brake light function rather than a combined running and stop light role.
The shift from the dual-filament 1157 to the single-filament 1156 between the 1991 and 1992 Mitsubishi Precis represents a change in circuit design, as the two bulb types are not interchangeable despite sharing a similar bayonet-style base family.
The BA15s base of the 1156 and the BAY15d base of the 1157 differ in pin alignment. The BAY15d base has offset pins to prevent incorrect installation of a single-filament bulb in a dual-filament socket, making cross-substitution physically restricted.
The Center High Mount Stop Light on the Mitsubishi Precis uses the 921 wedge bulb for 1987-1991 and transitions to the P21W for 1992-1994.
The 921 is a T15 wedge-base bulb rated at 12V, 16W. Its wedge construction requires no separate metal base, as the glass envelope itself is held in place by the socket contacts.
The P21W follows the ECE standard used in European and international markets. It is a single-filament signalling bulb rated at 12V, 21W, and shares the BA15s bayonet base with the ANSI 1156, though the two standards are not always treated as interchangeable across all applications.
The 921 wedge bulb used in the 1987-1991 Center High Mount Stop Light operates at 16W, which is lower than the 21W output of the P21W used in the 1992-1994 model years. The socket types for these two bulbs are physically incompatible with each other.
All bulb types specified across both positions on the Mitsubishi Precis operate on a 12V electrical system, consistent with standard automotive voltage.