While electric, hybrid and diesel power trains have been grabbing headlines in recent times, work continues unabated on the good ol’ gasoline internal combustion engine and some significant headway has been realized with the news of a new Nissan Micra which will run a supercharged, direct injection 1.2 litre power-plant. The lightweight, low-friction, three-cylinder engine emits just 95g/km, produces 72kW (98PS) and 142Nm, and delivers combined cycle fuel economy figures of a staggering 68.9mpg. The car will debut in Geneva, will be available in both manual and CVT transmissions and will have a healthy top speed of 112mph. Technical innovation has been packed into the engine. The DIG-S uses the Miller cycle and direct petrol injection to raise the compression ratio to 13 to 1 for greater combustion efficiency and a supercharger for instant throttle response and added power.
By minimizing heat, friction and pumping losses as much a possible, Nissan's engineers have created an engine that sets the standard for the rest of the industry. Its three-cylinder configuration gives many benefits including less weight and further reductions in friction loss, thanks to having fewer moving parts. Further gains are made thanks to the adoption of advanced engine management systems with Start/Stop and energy regeneration. One of the biggest advantages of a small car with such a frugal engine are very low running costs, not just from the fuel economy but also thanks to tax concessions based on its emissions and to lower servicing bills from the smaller engine. For example, cars producing less than 100g/km of CO2 attract no annual road tax in the UK and are exempt from London’s daily congestion charge.
The DIG-S will be given its European debut at the Geneva Motor Show (March 3-13) with sales starting mid-year.