From the start of 2012 the 1.4TSI engine will be available with a new fuel saving "cylinder shutdown" feature whereby the engine goes onto two cylinders between 1400 and 4000RPM in order to save fuel when being driven under "low loads"

This should save the driver around 1 litre of fuel per 100km of driving. Apparantly the change in number of fired cylinder when driving is imperceptable. If you push the throttle hard then the other cylinders immediately come back into play.

Sounds like a good idea which I can imagine spreading to all the TSI engines eventually. More info here: http://www.auto.cz/motor-vw-1-4-tsi-s-vypinanim-dvou-valcu-roku-2012-61317

Interesting, looks like the valve lift changes when in eco mode? Inverse of honda vtec/toyota vvti, adjusting the valve lift to reduce power/economy.

Have heard of cylinders being shutdown on large engines but not on a 4 cylinder. Wonder how smooth it will be.

More info in English

Linky

Link with video of how it works

I've driven cars with this system before but as mentioned above they didn't have 4 cylinders they where V8 and V12 and it was impossible to tell the difference.

I suspect they will perfect the technolodgy to suit the smaller engines, quite a good idea really!

Should lower the emissions too.

Should lower the emissions too.

which is one of the main reasons for doing it as the petrol engines are much higher emissions than the diesels in CO2.

Cadillac tried this back in the late 1970's early 1980's with their 4-6-8 engines, which ran on anything between 4 and 8 cylinders. It was a disaster and soon discontinued.

Cadillac tried this back in the late 1970's early 1980's with their 4-6-8 engines, which ran on anything between 4 and 8 cylinders. It was a disaster and soon discontinued.

It certainly seems to work well enough on Mercedes, so I'm sure the boffins at VW can make it work!