GDI

There are currently two GDI engines in the Mitsubishi 4x4 range, the 2.0-litre engine in the Shogun Pinin and the 3.5-litre V6 in the Shogun. These were the world's first production direct-injection petrol engines, the term direct-injection meaning that the mixing of fuel and air takes place inside the cylinder rather than in a chamber before entering the cylinder.

Aside from the Pinin and Shogun installation, the GDI engine is used as a 2.4-litre unit in the Space Wagon.

A key aspect of the high efficiency is the fuel-injection system which operates in two different combustion modes according to the demands the driver puts on the engine.

In conditions when there is only a low load on the engine, such as idling or driving at modest speeds where the accelerator is being pressed lightly, the GDI engine runs in 'Ultra-Lean Combustion Mode'. This means there is a higher proportion of air in the air/fuel mixture fed into the cylinders.

The driver knows when the engine is running in this mode thanks to a 'GDI-ECO' light that comes on in the instrument panel.

When a greater load is placed on the engine, in other words when increased power is sought by the driver, the GDI system goes into 'Superior Output Mode', during which a more conventional air/fuel mixture is employed. To provide greater torque for accelerating from low speed or a standing start, the fuel-injection switches to 'Two-Stage Mixing', whereby a second spray of fuel is fed into the chamber during the combustion cycle.

The precision of the fuel-air mixture is enhanced by the 'drive-by-wire' throttle, whereby the driver's 'instructions' to the engine are delivered electronically rather than by a traditional cable.

A telling indicator of the efficiency is that the Shogun's 3.5 V6 GDI engine delivers nearly 80 percent of its torque at an amazingly low 1500rpm - a characteristic that gives it supreme low-down pulling power. This is not only very useful on-road, but invaluable when tackling the toughest off-road terrain.