The latest engine efficiency technology from Volkswagen is a ground-breaking cylinder shut-off system, which will debut in a new 1.4-litre TSI powerplant in early 2012. With the primary goal of reducing fuel consumption, the engine temporarily shuts off two of the four cylinders under low to medium loads. Cylinder shut-off reduces fuel consumption of the 1.4-litre TSI by 0.4 litres per 100 km in the NEDC driving cycle, and when the company’s Start/Stop functionality is integrated – deactivating the engine in neutral gear – the savings adds up to 0.6 litres per 100 km.
The greatest benefits of the cutting-edge technology are realised while driving at constant moderate speeds. At 50km/h (31mph), in third or fourth gear, the savings amount to nearly one litre per 100 km. This new fuel efficient TSI will therefore also fulfil the forthcoming EU6 emissions standard. High efficiency does not exclude driving comfort: even when running on just two cylinders, the 1.4-litre TSI – with its excellent engine balance – is still very quiet and low in vibration.
Cylinder shut-off is active whenever the engine speed of the 1.4-litre TSI is between 1,400 and 4,000rpm and its torque is between 25 and 75Nm (18-55lb ft). This applies to nearly 70% of the driving distance in the EU fuel economy driving cycle. As soon as the driver presses the accelerator pedal sufficiently hard, cylinders 2 and 3 are reactivated imperceptibly. The system takes its information from the accelerator pedal sensor to detect the mode of driving. If the driving exhibits a non-uniform pattern – for example, while driving in roundabout traffic or in a sporty style on a country road – the shut-off functionality is automatically suppressed.