DIG-S Into Nissan's New Technoglogy

Representing the latest in low-emission engine technology, the DIG-S offers the performance of a bigger petrol engine but with the fuel economy of a diesel.

The ultra low emission 1.2-litre, three cylinder supercharged petrol engine emits from 95g/km to 99g/km depending on models. Official fuel consumption is 68.9mpg (29 kml) or 65.7mpg (28 kml) on the combined cycle, beating some similarly sized diesel models. Unlike most economy models though, the DIG-S also has a performance boost, with power rising from 80PS to 98PS.

The engine achieves the improvements in power and economy through a series of measures to improve efficiency. Direct injection, valve timing control with eco mode, improved exhaust gas recirculation, specially shaped pistons and a higher compression ratio ensure the most power is extracted from every drop of fuel.

To reduce inefficient power loss within the engine operating system the Miller Cycle is incorporated. By allowing the inlet valve to stay open longer, along with a higher compression ratio, the compression stroke becomes more efficient.

More energy is saved by using an intelligent alternator which recharges the battery when the engine power is not in demand, such as under braking. A stop / start function also helps to reduce emissions and fuel consumption by automatically turning off the engine whilst stationary and restarts again when you are ready to move off. The amount of CO2 saved during stop / start is displayed on the dashboard.

Credits: wilswong