Mitsubishi 4A3 engine

The Mitsubishi 4A3 engine is a range of alloy-headed inline four-cylinder engines from Mitsubishi Motors, introduced in 1993 in the sixth generation of their Mitsubishi Minica kei car. It shares a 72 mm bore pitch with the 3G8-series three-cylinder engines, but has a considerably shorter stroke so as to stay beneath the 660 cc limit imposed by the Kei class.

A 1094 cc version was made available in 1997 for larger cars, and was subsequently fitted to the Mitsubishi Pistachio, (and Pajero JR), a limited production car based on the kei class Minica equipped with the company's Automatic Stop-Go (ASG) system for cutting the engine when idling. So equipped, the Pistachio was able to record fuel economy figures of 30 km/L.

4A30
Displacement — 659 cc Bore x Stroke — 60x58.3 mm Fuel type — Unleaded regular gasoline

659 cc Electronic carburettor (1993)

 * Engine type — Inline 4-cylinder SOHC 16v
 * Fuel system — Electro carburettor
 * Compression ratio — 10.0:1
 * Power — 50 PS at 7500 rpm
 * Torque — 56 Nm at 5500 rpm

659 cc SOHC (1993)

 * Engine type — Inline 4-cylinder SOHC 16v
 * Fuel system — ECI multiple
 * Compression ratio — 10.0:1
 * Power — 55 PS at 7000 rpm
 * Torque — 60 Nm at 5000 rpm

659 cc DOHC turbo (1993)

 * Engine type — Inline 4-cylinder DOHC 20v
 * Fuel system — ECI multiple
 * Compression ratio — 8.5:1
 * Power — 64 PS at 7000 rpm
 * Torque — 97 Nm at 3500 rpm

4A31
Displacement — 1094 cc Bore x Stroke — 66x80 mm Fuel type — Unleaded regular gasoline

1094 cc SOHC (1997)

 * Engine type: Inline 4-cylinder SOHC 16v
 * Fuel system: ECI multiple
 * Compression ratio: 9.5:1
 * Power: Pajero Junior: 80 PS at 6000 rpm
 * Toppo BJ Wide: 78 PS at 6000 rpm
 * Town Box Wide: 75 PS at 6000 rpm


 * Torque: Pajero Junior: 10.0 kgm at 4000 rpm
 * Toppo BJ Wide: 10.5 kgm at 4000 rpm
 * Town Box Wide: 10.2 kgm at 4000 rpm

1094 cc GDI (1999)

 * Engine type: Inline 4-cylinder DOHC 16v
 * Fuel system: GDI Direct Injection
 * Compression ratio: 11.0:1
 * Power: 74 PS at 6000 rpm
 * Torque: 100 Nm at 4000 rpm