Volkswagen gains cylinder deactivation
4th September, 2011
Volkswagen’s latest efficiency technology, a cylinder shut-off
system, will debut in the new 1.4-litre TSI engine from the start of 2012. This is a large step for Volkswagen
in terms of saving fuel.
The primary goal of the high-tech system is to reduce fuel consumption significantly by temporarily shutting
off two of the four cylinders under low to medium loads. In fact, cylinder shut-off reduces fuel consumption of
the 1.4-litre TSI by 0.4 litre per 100 km in the NEDC driving cycle. When Start/Stop functionality is integrated,
which deactivates the engine in neutral gear, the savings effect adds up to about 0.6 litre per 100 km.
The greatest benefits of the technology are realised while driving at constant moderate speeds. At 50 km/h, in
third or fourth gear, savings amount to nearly one litre per 100 km. This new fuel efficient TSI will therefore
also fulfil the future 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 4,000 rpm and
its torque is between 25 and 75 Nm. This applies to nearly 70 per cent 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 – shut-off functionality is automatically suppressed.